Area of the Columns cross section on the Floor Plan, including the area of the veneer, if any.
Core Dimension 2 - For a rectangular or profiled Column: One of the two dimensions of the Column in cross-section. (The other dimension is Core Dimension 1.)
For a rectangular or profiled Column: One of the two dimensions of the Column in cross-section. (The other dimension is Core Dimension 1.)
For a circular Column: the diameter of the Column in cross-section.
Core Dimension 1 - For a rectangular or profiled Column: One of the dimensions of the Column in cross-section. (The other dimension is Core Dimension 2.) Not applicable to circular Columns.
For a rectangular or profiled Column: One of the dimensions of the Column in cross-section. (The other dimension is Core Dimension 2.) Not applicable to circular Columns.
Column Cross Section - Shape of the Columns cross-section (rectangular, circular or profiled) as defined in the Settings dialog box.
Shape of the Columns cross-section (rectangular, circular or profiled) as defined in the Settings dialog box.
Building Material/Profile - Name of the Building Material assigned to the Column core (or the name of the Profile, in case of a profiled Column.)
Name of the Building Material assigned to the Column core (or the name of the Profile, in case of a profiled Column.)
Height - Height of the Column. (If the top of a Column is uneven and thus has two heights, e.g. due to a Roof trim, Height = Maximum Height.
Height of the Column. (If the top of a Column is uneven and thus has two heights, e.g. due to a Roof trim, Height = Maximum Height.
See also Maximum/Minimum height parameters.)
Top link story - Name of Columns top-linked Story, if any.
Name of Columns top-linked Story, if any.
Top offset - Offset (if any) of Column from its top-linked Story.
Offset (if any) of Column from its top-linked Story.
Maximum height of the Column - For a straight or slanted Column: equivalent to Height. For a Column cut e.g. by a slanted Roof: the highest point of the Column.
For a straight or slanted Column: equivalent to Height. For a Column cut e.g. by a slanted Roof: the highest point of the Column.
Minimum height of the Column - For a straight or slanted Column: equivalent to Height. For a Column cut e.g. by a slanted Roof: the lowest point of the Column.
For a straight or slanted Column: equivalent to Height. For a Column cut e.g. by a slanted Roof: the lowest point of the Column.
Surface - Surface assigned to Column (in Settings dialog box).
Surface assigned to Column (in Settings dialog box).
Perimeter of the Columns cross section. - Slant Angle
Slant Angle - Slant angle of a slanted Column.
Slant angle of a slanted Column. - Net Surface area of the Column core on all sides, not including the surface of the Column top or bottom. Takes Solid Element Operations into account.
Net Surface area of the Column core on all sides, not including the surface of the Column top or bottom. Takes Solid Element Operations into account.
Gross surface area of the core (without top/bottom)
Gross surface area of the Column core on all sides, not including the surface of the Column top or bottom. Does not take any Solid Element Operations into account.
Gross surface area of the core top (or bottom)
Surface area of the cross-section of the core at the top (or bottom) of the Column. Does not take any Solid Element Operations into account.
Gross surface area of the veneer (without top/bottom)
Gross surface area of the Column veneer on all sides, not including the surface of the veneer at the top or bottom of the Column. Does not take any Solid Element Operations into account.
Gross surface area of the veneer top (or bottom)
Surface area of the cross section of the veneer at the top (or bottom) of the Column. Does not take any Solid Element Operations into account.
Net surface area of the core bottom - Surface area of the cross-section of the core at the bottom of the Column.Takes Solid Element Operations into account.
Surface area of the cross-section of the core at the bottom of the Column.Takes Solid Element Operations into account.
Net surface area of the core top - Surface area of the cross-section of the veneer at the top of the Column. Takes Solid Element Operations into account.
Surface area of the cross-section of the veneer at the top of the Column. Takes Solid Element Operations into account.
Net surface area of the veneer bottom - Surface area of the cross-section of the veneer at the bottom of the Column. Takes Solid Element Operations into account.
Surface area of the cross-section of the veneer at the bottom of the Column. Takes Solid Element Operations into account.
Net surface area of the veneer top - Surface area of the cross-section of the veneer at the top of the Column.Takes Solid Element Operations into account.
Surface area of the cross-section of the veneer at the top of the Column.Takes Solid Element Operations into account.
Net Surface Area of the Veneer - Net Surface area of the Column veneer on all sides, not including the surface of the veneer at the top or bottom of the Column. Takes Solid Element Operations into account.
Net Surface area of the Column veneer on all sides, not including the surface of the veneer at the top or bottom of the Column. Takes Solid Element Operations into account.
Veneer Building Material - Name of Building Material assigned to veneer (in Column Settings dialog box).
Name of Building Material assigned to veneer (in Column Settings dialog box).
Veneer Type - Definition of veneer as either Core, Finish or None, as defined in the Settings dialog box (Geometry and Positioning Panel). Veneer Type will affect the display of the Column, which is determined by the Partial Structure Display Settings.
Definition of veneer as either Core, Finish or None, as defined in the Settings dialog box (Geometry and Positioning Panel). Veneer Type will affect the display of the Column, which is determined by the Partial Structure Display Settings.
Net volume of the core - Net volume of the Column core. Takes Solid Element Operations into account.
Net volume of the Column core. Takes Solid Element Operations into account.
Gross volume of the Column - Gross volume of the Column, including the volume of both the core and veneer, if any. Does not take any Solid Element Operations into account.
Gross volume of the Column, including the volume of both the core and veneer, if any. Does not take any Solid Element Operations into account.
Gross volume of the core - Gross volume of the Column core. Does not take any Solid Element Operations into account.
Gross volume of the Column core. Does not take any Solid Element Operations into account.
Gross volume of the veneer - Gross volume of the Column veneer. Does not take any Solid Element Operations into account.
Gross volume of the Column veneer. Does not take any Solid Element Operations into account.
Net volume of the veneer - Net volume of the Column veneer on all sides. Takes Solid Element Operations into account.
Net volume of the Column veneer on all sides. Takes Solid Element Operations into account.
Volume of the Column - Net volume of the Column (including the volume of the core and of the veneer, if any). Takes Solid Element Operations into account.
Net volume of the Column (including the volume of the core and of the veneer, if any). Takes Solid Element Operations into account.
Height of the Curtain Wall, defined in Curtain Wall System Settings or the Info Box.
Length of the Curtain Wall - Number of Panels
Number of Panels - Number of panels in the Curtain Wall.
Number of panels in the Curtain Wall. - Rotation angle of the Secondary Grid Lines measured clockwise from the Primary Grid Lines. This angle is defined in the Curtain Wall Scheme Settings/Grid Pattern panel, under Secondary Gridlines.
Rotation angle of the Secondary Grid Lines measured clockwise from the Primary Grid Lines. This angle is defined in the Curtain Wall Scheme Settings/Grid Pattern panel, under Secondary Gridlines.
Slant Angle - Slant angle of the Curtain Wall, defined in Curtain Wall System Settings or the Info Box.
Slant angle of the Curtain Wall, defined in Curtain Wall System Settings or the Info Box.
Surface Area Including Boundary - Surface area of Curtain Wall, including the surface area of its Boundary Frames.
Surface area of Curtain Wall, including the surface area of its Boundary Frames.
If the Boundary Frames are placed Inside Grid (Curtain Wall Settings/Curtain Wall System/ Member Placement: Place Boundary Frames Inside), then this parameter is equal to the general Surface Area parameter for the Curtain Wall.
If the Boundary Frames are placed Outside Grid or Centered on Grid, then the value of this parameter will exceed the general Surface Area parameter, because the Boundary Frames hang out over the boundary line.
If you use an Invisible type Frame for your Boundary Frames (Curtain Wall Settings/Curtain Wall System/Frames: Boundary), then the value of this parameter will be less than that of the general Surface Area parameter.
Thickness - Defined in Curtain Wall System Settings or the Info Box. The distance from the Reference Surface to the opposite side of the Curtain Wall.
Defined in Curtain Wall System Settings or the Info Box. The distance from the Reference Surface to the opposite side of the Curtain Wall.
Total Length of Frames - Total of the lengths of all frames in the Curtain Wall. If the shape of the Frame is not uniform, then the value of the Frame length is calculated by taking the average of its shortest and longest lengths.
Total of the lengths of all frames in the Curtain Wall. If the shape of the Frame is not uniform, then the value of the Frame length is calculated by taking the average of its shortest and longest lengths.
Total Panel Surface Area - Total surface area of all the Curtain Wall panels. This value does not include the surface of the frames between the panels. Total Panel Surface Area is seen if you look at the Curtain Wall in Edit mode, with just the Panels visible.
Total surface area of all the Curtain Wall panels. This value does not include the surface of the frames between the panels. Total Panel Surface Area is seen if you look at the Curtain Wall in Edit mode, with just the Panels visible.
Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Building Material/Composite/Profile - Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Height - Height of the Beam (difference between its base elevation and its top elevation)
Height of the Beam (difference between its base elevation and its top elevation)
Hole Height - Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Hole Level - Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Hole Number - Total number of holes in the Beam.
Total number of holes in the Beam. - Hole Width
Hole Width - Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Holes Surface Area - Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Holes Volume - Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Length Left - Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length Right - Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Bottom surface - Name of the surface assigned to the bottom surface of the Beam.
Name of the surface assigned to the bottom surface of the Beam.
Left side surface - Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Right side surface - Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
End surface - Name of the surface assigned to the two end surfaces of the Beam.
Name of the surface assigned to the two end surfaces of the Beam.
Top surface - Name of the surface assigned to the top surface of the Beam.
Name of the surface assigned to the top surface of the Beam.
Offset - Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Slant Angle - Angle of an inclined Beam.
Bottom Surface Area - Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Left side surface area - Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Right side surface area - Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
End Surface Area - Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Top Surface Area - Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Volume - Volume of the Beam, reduced by any SEOs or holes.
Volume of the Beam, reduced by any SEOs or holes.
Conditional Volume - Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by). Takes SEOs into account.
Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by). Takes SEOs into account.
Width - Width of the Beam as entered in Info Box or Beam Tool Settings
Width of the Beam as entered in Info Box or Beam Tool Settings
Name of the Slabs Building Material or its composite structure.
Name of the cover fill (if any) assigned to the Slab.
Gross volume of the Slab - Volume of Slab, subtracting the volume of any holes.
Volume of Slab, subtracting the volume of any holes.
Value is reduced by any trims, but does not take SEOs into account.
Holes Perimeter - Total perimeter of all holes in the Slab, measured according to the Slabs 2D polygon. Does not take SEOs into account.
Total perimeter of all holes in the Slab, measured according to the Slabs 2D polygon. Does not take SEOs into account.
Bottom Surface - Name of the surface assigned to the bottom surface of the Slab.
Name of the surface assigned to the bottom surface of the Slab.
Edge Surface - Name of the surface assigned to the edges of the Slab.
Name of the surface assigned to the edges of the Slab.
Note: Even if the listed Slab edge has a custom surface, the listed surface is the Slabs edge surface as shown in the Model panel of Slab Settings.
Top Surface - Name of the surface assigned to the top surface of the Slab.
Name of the surface assigned to the top surface of the Slab.
Perimeter - Perimeter of the Slab, including the perimeters of any holes, measured according to the Slabs 2D polygon.
Perimeter of the Slab, including the perimeters of any holes, measured according to the Slabs 2D polygon.
Net surface area of the bottom - Area of the surface of the bottom of the Slab reduced by any trims, SEOs or holes.
Area of the surface of the bottom of the Slab reduced by any trims, SEOs or holes.
Conditional surface area of the bottom - Surface area of the bottom of the Slab, subtracting the surface of any openings that exceed a given area as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab surface by). Takes trims and SEOs into account.
Surface area of the bottom of the Slab, subtracting the surface of any openings that exceed a given area as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab surface by). Takes trims and SEOs into account.
Conditional surface area of the top - Surface area of the top of the Slab, subtracting the surface of any openings that exceed a given area as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab surface by). Takes trims and SEOs into account.
Surface area of the top of the Slab, subtracting the surface of any openings that exceed a given area as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab surface by). Takes trims and SEOs into account.
Edge Surface Area - Area of the surface of the edge of the Slab, taking any trims, SEOs or holes into account.
Area of the surface of the edge of the Slab, taking any trims, SEOs or holes into account.
Gross surface area of the slab bottom - Area of the surface of the bottom of the Slab, subtracting the surface of any holes. Value is reduced by any trims, but does not take SEOs into account.
Area of the surface of the bottom of the Slab, subtracting the surface of any holes. Value is reduced by any trims, but does not take SEOs into account.
Gross surface area of the slab edges - Area of the surface of all the Slab edges. Value is reduced by any trims, but does not take SEOs into account.
Area of the surface of all the Slab edges. Value is reduced by any trims, but does not take SEOs into account.
Gross surface area of the slab top - Area of the surface of the top of the Slab, subtracting the surface of any holes. Value is reduced by any trims, but does not take SEOs into account.
Area of the surface of the top of the Slab, subtracting the surface of any holes. Value is reduced by any trims, but does not take SEOs into account.
Holes Surface Area - Total top surface area of all holes in the Slab, measured according to the Slabs 2D polygon. Does not take SEOs into account.
Total top surface area of all holes in the Slab, measured according to the Slabs 2D polygon. Does not take SEOs into account.
Net surface of the top - Area of the surface of the top of the Slab, reduced by any trims, SEOs or holes.
Area of the surface of the top of the Slab, reduced by any trims, SEOs or holes.
Thickness - Thickness of the Slab (as defined in the Thickness field of Slab Settings).
Thickness of the Slab (as defined in the Thickness field of Slab Settings).
Elevation of the bottom of the Slab - Elevation Top
Elevation Top - Elevation of the top of the Slab
Elevation of the top of the Slab - Net volume of the Slab, subtracting the volume of holes if any, and subtracting the effect of trims and Solid Element Operations.
Net volume of the Slab, subtracting the volume of holes if any, and subtracting the effect of trims and Solid Element Operations.
Conditional volume - Volume of the Slab, subtracting the volume of any openings that exceed a given size as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab volume by). Takes trims and SEOs into account.
Volume of the Slab, subtracting the volume of any openings that exceed a given size as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab volume by). Takes trims and SEOs into account.
The angle of rotation from the black ray to the green segment is 60, from the black ray to the blue segment is 210, and from the green to the blue segment is 210 60 = 150. A complete rotation about the center point is equal to 1 turn, 360, or 2 radians.
In mathematics, the angle of rotation is a measurement of the amount, of namely angle, that a figure is rotated about a fixed point, often the center of a circle. A clockwise rotation is considered a negative rotation, so that, for instance, a rotation of 310 (counterclockwise) can also be called a rotation of 50 (since 310 + 50 = 360, a full rotation (turn)). A counterclockwise rotation of more than one complete turn is normally measured modulo 360, meaning that 360 is subtracted off as many times as possible to leave a non-negative measurement less than 360.
For example, the carts on a Ferris wheel move along a circle around the center point of that circle. If a cart moves around the wheel once, the angle of rotation is 360. If the cart was stuck halfway, at the top of the wheel, at that point its angle of rotation was only 180.
This is also referred to as the "order of symmetry."
A O F ( 360 a + b ) = A O F ( b ) {\displaystyle AOF(360a+b)=AOF(b)} for all integer a and real b.
Jandris Block - If you have questions about specific products or services we provide, please dont hesitate to contact us.
If you have questions about specific products or services we provide, please dont hesitate to contact us.
TEK 14-14 - CONCRETE MASONRY ARCHES
CONCRETE MASONRY ARCHES - INTRODUCTION
INTRODUCTION - The masonry arch, one of mans oldest architectural forms, is defined as a rigid span curving upward between two points of support. The arch appears in a wide variety of structures ranging from the purely decorative triumphal arch to the masonry arch bridge where it sustains great loads.
The masonry arch, one of mans oldest architectural forms, is defined as a rigid span curving upward between two points of support. The arch appears in a wide variety of structures ranging from the purely decorative triumphal arch to the masonry arch bridge where it sustains great loads.
The round arch, Figure 1, was used by the early Chinese in all types of buildings. In ancient Egypt, this arch and others were used in nonceremonial structures such as engineering works and private dwellings. The Babylonians, on the other hand, used their arches in temples, palaces, and tombs. The Romans used the arch freely in their secular structures, as in the Colosseum, and in their engineering works like the aqueduct, but in their temples they followed the Greek style with the horizontal entablature.
Many forms of the arch have been developed during the centuries of its use, ranging from the flat or jack arch through the segmental, circular, parabolic to the pointed Gothic. Used freely in the great cathedrals of Europe, the Gothic or pointed arch had a structural use more important than the ornamental effect, as it minimized the outward thrust, making possible the firmness and stability combined with the lofty and spacious interior characteristic of the Gothic cathedral.
Two distinct types of arches have been recognized based on span, rise, and loading. The more common concrete masonry arch is the minor arch where maximum span is limited to about 6 feet (1.8 m) with a rise-to-span ratio not exceeding 0.15, and carrying loads up to 1500 lb per foot of span (21,891 N/m). The second type of arch is the major arch where span, rise, and loading may exceed those of the minor. Illustrations of both types of arches are shown in Figure 1. However, the design section of this TEK discusses only minor arches.
Figure 1Masonry Arch Forms - ANALYSIS
ANALYSIS - Fixed masonry arches are statically indeterminate to the third degree, that is, they have three reaction components or force paths that could be eliminated without adversely effecting their stability. This redundancy is a hidden asset of masonry; the tendency for arching action provides a masonry wall with resistance to progressive type failure. When a hole is caused suddenly in a masonry wall, an arch is created over the opening and the wall continues to carry load rather than fall down.
Fixed masonry arches are statically indeterminate to the third degree, that is, they have three reaction components or force paths that could be eliminated without adversely effecting their stability. This redundancy is a hidden asset of masonry; the tendency for arching action provides a masonry wall with resistance to progressive type failure. When a hole is caused suddenly in a masonry wall, an arch is created over the opening and the wall continues to carry load rather than fall down.
This redundancy of the masonry arch is, however, a nuisance when one considers design. Because the masonry arch is statically indeterminate, arches in building walls are generally designed or analyzed by approximate methods; the degree of exactness of the design procedure depends upon the size (span & rise) of the arch. Minor arches with spans of up to 6 feet (1.8 m) and rise-to-span ratios not exceeding 0.15 may be satisfactorily designed by the hypothesis of least crown thrust first proposed by Mosely in 1837. Major arches may be designed by considering them as essentially thick curved elastic beams. Many methods of elastic analysis have been developed; however, in most instances the application is complicated and time consuming. And, it is still an approximate analysis since the equations are developed assuming that deformations within the arch are small enough that the stresses are not affected if these deformations are ignored. This is not true of long span bridges where secondary stresses are significant and are taken into account. In masonry arches for building walls they can be ignored safely.
Figure 2 shows the forces and reactions within and upon a minor concrete masonry arch. The external load may consist of a uniform load, w, as shown, a concentrated load, or other. A horizontal thrust, H, is assumed to act at the crown, and its point of application is assumed to be at the upper middle-third limit (upper edge of kern) of the arch section. At the skewback (left-hand reaction), a reaction, F, is assumed to act at the lower middle-third limit (lower edge of kern) of the section. These assumptions for the design of minor arches, that the equilibrium polygon lies entirely within the middle third of the arch section, preclude the rotation of one section of the arch about the edge of a joint or the development of tensile stresses in either the intrados or extrados. The assumptions appear reasonable for symmetrical arches loaded equally and symmetrically, but may not be tenable for unsymmetrical arches or nonuniform loading. A vertical shear, VO, is shown also at the crown of the arch. This shear will equal zero when both halves of the arch are loaded equally, i.e., the general case.
There are four items to consider regarding structural failure of minor unreinforced concrete masonry arches:
failure due to tensile stresses (already eliminated by the assumption that the force polygon remains within the section kern)
crushing of the masonry due to compression by the horizontal thrust, H
shear sliding failure of one section of the arch along another, or along the skewback
the ability of supporting adjacent masonry wall or abutment to safely resist the horizontal thrust, H, of the arch.
Consider first the crushing of the masonry due to horizontal thrust. For minor arches (segmental or jack arches) the relationship between vertical loading or vertical reaction, V1 or W, and horizontal thrust, H, depends on the rise-to-span ratio, r/S, of the arch, and on the span/depth ratio, S/d. This relationship is shown in Figure 3. Knowing r/S and S/d of an arch, read the value W/2 H at the left-hand side of the graph. (Note: flat or jack arches are represented as r/S = 0).
Once the horizontal thrust has been determined, the maximum compressive stress in the masonry is determined by the following formula:
This value is twice an axial compressive stress on the arch due to a load H because the horizontal thrust is located at the edge of the kern.
Shear stress, or sliding of one section of the arch on another or on the skewback, requires consideration of the angular relationship of the reaction and the mortar joint, Figure 4. Stresses acting on the joint will depend on the angle formed between the reaction, F, and the inclined joint. This angle is:
For segmental arches with radial joints, the angle between the skewback and the vertical is:
or in terms of radius of curvature, R:
For jack or flat arches in which the skewback equals inch per foot of span (83 mm/m) for each 4 inches (102 mm) of arch depth, the angle that the skewback makes with the vertical is:
In these ratios all terms of length must be expressed in the same units; for example, in computing S/r, S/d, and S/R, if S is in feet (m), r, d, and R must be in feet (m) also.
Shear force, Q, along the mortar joint is then equal to:
Finally, a check should be made to make certain the supporting adjacent masonry wall has sufficient shear strength and resistance to overturning against the horizontal thrust, H, of the concrete masonry arch. Figure 5 illustrates how shear resistance may be calculated. It is assumed that the horizontal thrust of the arch attempts to move a volume of masonry enclosed by the boundary lines ABCD and CDEF. The thrust, H, is acting against two shear planes of resistance, CF and DE. Shear stress along either plane can then be calculated as:
The tendency for the arch thrust, H, to overturn the supporting masonry wall must be checked, especially when the arch is near the wall top. No tension due to overturning moment should be permitted in the supporting wall section. Applicable equations are:
M = overturning moment due to thrust H h = wall height f = stress at bottom of wall P = vertical load on wall An = net area of wall I = moment of inertia of wall based on length and equivalent solid thickness c = distance from neutral axis, 1/2 wall length
Figure 2Assumed Conditions for Static Analysis of Small Concrete Masonry Arch
Figure 3Relationship of Vertical Load, W, and Horizontal Thrust, H, in Small Concrete Masonry Arches
Figure 4Angular Relationship Between Forces and Stresses in Radial Joint of Segmental and/or Jack Arches
Figure 5Supporting Adjacent Masonry Must Resist the Horizontal Thrust of the Arch
CONSTRUCTION - Since any section of an arch may be subjected to shear, moment, and thrust, it is important that arches be constructed with high quality concrete masonry units, mortar, and good workmanship. For this reason, the use of mortar conforming to ASTM C 270 (ref. 5), Type M, S, or N is recommended. Bond is an important factor in building arches with sufficient shear resistance to withstand the imposed loads. To obtain good bond, all mortar joints in the arch need to be completely filled. This is sometimes very difficult to do, especially where the concrete masonry units are laid in soldier bond or rowlock header bond. It is also hard to do where the curvature of the arch is of short radius, and mortar joints of varying thickness are used. But completely filled joints are paramount to a strong arch, and can be achieved with quality workmanship.
Since any section of an arch may be subjected to shear, moment, and thrust, it is important that arches be constructed with high quality concrete masonry units, mortar, and good workmanship. For this reason, the use of mortar conforming to ASTM C 270 (ref. 5), Type M, S, or N is recommended. Bond is an important factor in building arches with sufficient shear resistance to withstand the imposed loads. To obtain good bond, all mortar joints in the arch need to be completely filled. This is sometimes very difficult to do, especially where the concrete masonry units are laid in soldier bond or rowlock header bond. It is also hard to do where the curvature of the arch is of short radius, and mortar joints of varying thickness are used. But completely filled joints are paramount to a strong arch, and can be achieved with quality workmanship.
Concrete masonry units for arch construction should be either 100 percent solid units, or filled units, or filled cell construction. Applicable ASTM Specifications are: Concrete Building Brick, ASTM C 55 (ref. 3); Calcium Silicate Face Brick, ASTM C 73 (Sand-Lime Brick) (ref. 2); Load-Bearing Concrete Masonry Units, ASTM C 90 (ref. 4).
Concrete masonry arches are constructed with the aid of a form or temporary support. After construction, the form is kept in place until the arch is strong enough to carry the loads to which it will be subjected. For unreinforced concrete masonry arches, the form should remain in place about one week after construction.
Finally, the wall supporting the concrete masonry arch must be considered. With a masonry arch, three conditions relating to the supporting wall must be maintained in order to ensure arch action: the length of the span must remain constant; the elevation of the arch ends must remain unchanged; and the inclination of the skewback must remain fixed. If any of these conditions are violated by sliding, settlement, or rotation of the supporting abutments, critical stresses for which the arch was not designed may result.
DESIGN EXAMPLESEGMENTAL ARCH - A segmental arch is to be supported on an unreinforced 8-inch (203 mm) hollow loadbearing wall. One end of the arch will be 24 inches (610 mm) from the end of the wall. Other given data are:
A segmental arch is to be supported on an unreinforced 8-inch (203 mm) hollow loadbearing wall. One end of the arch will be 24 inches (610 mm) from the end of the wall. Other given data are:
SUMMARY: The arch is sufficient to carry the loads, but the supporting wall will require reinforcement to increase its shear capacity.
References - Leontorich, V. Frames and Arches. McGraw-Hill, 1959.
Leontorich, V. Frames and Arches. McGraw-Hill, 1959.
Standard Specification for Calcium Silicate Face Brick (Sand-Lime Brick), ASTM C 73-94. American Society for Testing and Materials, 1994.
Standard Specification for Concrete Building Brick, ASTM C 55-94. American Society for Testing and Materials, 1994.
Standard Specification for Load-Bearing Concrete Masonry Units, ASTM C 90-94. American Society for Testing and Materials, 1994.
Standard Specification for Mortar for Unit Masonry, ASTM C 270-92a. American Society for Testing and Materials, 1992.
Dado (architecture) - Diagram of a wall illustrating (orange strips) the crown moulding (top), dado rail (middle) and the skirting board (lower). The dado lies between the dado rail and the skirting board.
Diagram of a wall illustrating (orange strips) the crown moulding (top), dado rail (middle) and the skirting board (lower). The dado lies between the dado rail and the skirting board.
In architecture, the dado is the lower part of a wall,[1] below the dado rail and above the skirting board. The word is borrowed from Italian meaning "dice" or "cube",[2] and refers to "die", an architectural term for the middle section of a pedestal or plinth.[3]
Contents - This area is given a decorative treatment different from that for the upper part of the wall; for example panelling, wainscoting or lincrusta. The purpose of the dado treatment to a wall is both aesthetic and functional. Historically, the panelling below the dado rail was installed to cover the lower part of the wall which was subject to stains associated with rising damp; additionally it provided protection from furniture and passing traffic. The dado rail itself is sometimes referred to misleadingly as a chair rail, though its function is principally aesthetic and not to protect the wall from chair backs.
This area is given a decorative treatment different from that for the upper part of the wall; for example panelling, wainscoting or lincrusta. The purpose of the dado treatment to a wall is both aesthetic and functional. Historically, the panelling below the dado rail was installed to cover the lower part of the wall which was subject to stains associated with rising damp; additionally it provided protection from furniture and passing traffic. The dado rail itself is sometimes referred to misleadingly as a chair rail, though its function is principally aesthetic and not to protect the wall from chair backs.
Dado meaning the middle section or main body of a pedestal
The name was first used in English as an architectural term for the part of a pedestal between the base and the cornice. As with many other architectural terms, the word is Italian in origin. The dado in a pedestal is roughly cubical in shape, and the word in Italian means "dice" or "cube" (ultimately Latin datum, meaning "something given", hence also a die for casting lots).[2][4] By extension, the dado becomes the lower part of a wall when the pedestal is treated as being continuous along the wall, with the cornice becoming the dado rail.[3]
Breadcrumb - Number of occupants per room
Number of occupants per room - The occupant density per room indicates the number of persons per room. This indicator is examined from various aspects: household characteristics, buildings and dwellings.
The occupant density per room indicates the number of persons per room. This indicator is examined from various aspects: household characteristics, buildings and dwellings.
Occupant density per room by number of rooms since 1970
Sources: FSO - Federal Population Census, Buildings and dwellings statistics
In 2019, more than one in two households was living in a dwelling with more than 2 rooms per person.
Occupant density per room by nationality and household composition, 2019
Swiss household: all members Swiss nationals Swiss-foreign household: at least one Swiss national and one foreign national Foreign household: all members foreign nationals Source: FSO - Buildings and dwellings statistics
Statistical sources and concepts - Contact
Contact - Federal statistical office Section Population Espace de lEurope 10 CH-2010 Neuchtel Switzerland
Federal statistical office Section Population Espace de lEurope 10 CH-2010 Neuchtel Switzerland
Remark - Our English pages offer only a limited range of information on our statistical production. For our full range please consult our pages in French and German (top right hand screen).
Our English pages offer only a limited range of information on our statistical production. For our full range please consult our pages in French and German (top right hand screen).
Door frames - A door frame is the structure the door leaf or panel is fitted to and provides a solid structure within a rough opening. For hinged doors, the hinges attach to the frame; for sliding doors, the track is fitted to a frame for rollers to slide across; and folding doors have hinges and tracks in their frames. They come in different sizes to fit the size of the opening and the depth of the wall.
A door frame is the structure the door leaf or panel is fitted to and provides a solid structure within a rough opening. For hinged doors, the hinges attach to the frame; for sliding doors, the track is fitted to a frame for rollers to slide across; and folding doors have hinges and tracks in their frames. They come in different sizes to fit the size of the opening and the depth of the wall.
The strength and durability of a door frame will affect the longevity of the door itself. A weak or poorly fitted door frame can pose a security risk and is likely to wear out much quicker. You will also find that the quality of the door frame will influence the insulation provided; gaps in a frame can let cold air in and warm air out.
Whatever the shape, a door frame's primary job is to provide a seal around the door. Interior and exterior door frames will usually have different properties, as frames used outside will have to face the elements.
When you buy a door you will usually have the option to have it pre-hung, as a door sets. This means the door will come with hinges and frame already attached. This should make installation quicker, as the door will already be firmly in place in its frame. This option is also useful for new builds, or if you need to replace the frame, as well as the door. While internal doors sets are usually bought in separate parts with a door slab and door frame (lining) external door sets are a popular choice for the modern home, as they are complete and ready to install into a rough opening.
Doors sold without being fitted to a frame are usually called slab doors. These doors will be cheaper than a pre-hung door, so if you're just replacing the door itself, and you can find the right size, this might be the best option. To replace a frame and door with separate parts is more difficult, as getting the exact dimensions is so important. If you are replacing an external door frame, you need to ensure you follow Building Regulations.
Here at Wonkee Donkee XL Joinery we stock XL Joinery frames for external doors and linings for internal doors. We also have an excellent range of frames for folding room dividers or internal French door sets, to suit various rooms in your home, including bathrooms, kitchens, living rooms and patios.
Internal door frames - Internal door frames, usually called door linings, are usually constructed to span the thickness of the wall, so they're not significantly recessed into the gap. They tend to be more forgiving than external door frames when making adjustments to ensure the frame is square because any gaps between the frame the wall will usually be covered with architrave.
Internal door frames, usually called door linings, are usually constructed to span the thickness of the wall, so they're not significantly recessed into the gap. They tend to be more forgiving than external door frames when making adjustments to ensure the frame is square because any gaps between the frame the wall will usually be covered with architrave.
Internal door frames are often open frames, or they may have particularly low sills, or ones which recess into the flooring to sit flush. They will not be as sturdy as external frames, as they don't need to be as strong or durable, and they will be easier for a DIYer to assemble themselves if they choose to.
What are the parts of an internal door frame?
Head - The head of a door frame can sometimes be called the upper jamb or lintel. This horizontal piece sets the width of the frame where the door will be fitted. The head will usually have grooves for jambs to fit into, and often have two sets of these grooves for different widths of frame. Any material which extends past the jambs can be cut off if the frame is not to be built into an opening.
The head of a door frame can sometimes be called the upper jamb or lintel. This horizontal piece sets the width of the frame where the door will be fitted. The head will usually have grooves for jambs to fit into, and often have two sets of these grooves for different widths of frame. Any material which extends past the jambs can be cut off if the frame is not to be built into an opening.
Jambs - The jambs are the side pieces of the frame, running vertically. They're sometimes called the legs. One of the jambs is where the hinges will be attached, to hang the door. This is sometimes called the hinge jamb. The other side is where a strike plate or lock keep will be fitted, and is sometimes called the latch jamb. The width of the jambs usually matches the width of the wall.
The jambs are the side pieces of the frame, running vertically. They're sometimes called the legs. One of the jambs is where the hinges will be attached, to hang the door. This is sometimes called the hinge jamb. The other side is where a strike plate or lock keep will be fitted, and is sometimes called the latch jamb. The width of the jambs usually matches the width of the wall.
Stops - The stops are thin strips which are fitted to the jambs, or occasionally moulded into the jambs themselves, sometimes called rebated jambs. They catch the door when it's closed, so it can only be opened one way. This is necessary to stop the door going too far and breaking the hinges. Stops are not fitted on swing doors, which can be opened from either side of the frame.
The stops are thin strips which are fitted to the jambs, or occasionally moulded into the jambs themselves, sometimes called rebated jambs. They catch the door when it's closed, so it can only be opened one way. This is necessary to stop the door going too far and breaking the hinges. Stops are not fitted on swing doors, which can be opened from either side of the frame.
Sill - The sill, or threshold, of a door frame, is the bottom, horizontal section. The door will rest against this piece when it's closed, which will close the gap between the bottom of the door and the floor. Internal frames usually don't have sills. If they do, they will normally be low profile sills for easy access and are generally used to separate rooms with different types of flooring, or there will just be a simple floor profile in the place where a sill would be.
The sill, or threshold, of a door frame, is the bottom, horizontal section. The door will rest against this piece when it's closed, which will close the gap between the bottom of the door and the floor. Internal frames usually don't have sills. If they do, they will normally be low profile sills for easy access and are generally used to separate rooms with different types of flooring, or there will just be a simple floor profile in the place where a sill would be.
Architrave - The architrave borders a frame, and its role is decorative rather than structural. It can also be called door trim, moulding, or casting. Architrave covers most of the frame and hides the gap where it joins to the wall. Architrave can be plain or moulded into various designs, and will often be finished to match skirting boards or dado rails.
The architrave borders a frame, and its role is decorative rather than structural. It can also be called door trim, moulding, or casting. Architrave covers most of the frame and hides the gap where it joins to the wall. Architrave can be plain or moulded into various designs, and will often be finished to match skirting boards or dado rails.
External door frames - External door frames are usually recessed within a wall due to the increased thickness of external walls. Because of this, they need to be more accurately fitted into a rough opening because any gaps between the frame and the wall will often just be sealed with silicone and not trimmed with architrave. If external doors have any architrave it's usually called moulding. External doors usually have stops built into the jambs, rather than fitted separately.
External door frames are usually recessed within a wall due to the increased thickness of external walls. Because of this, they need to be more accurately fitted into a rough opening because any gaps between the frame and the wall will often just be sealed with silicone and not trimmed with architrave. If external doors have any architrave it's usually called moulding. External doors usually have stops built into the jambs, rather than fitted separately.
External door frames are usually sold as closed frames, as the sill is an important seal to prevent leaks. If you buy an open frame you need to ensure you also use a suitable sill. Flush sills on external doors need to incorporate a channel for collecting and draining rain water. External frames often come ready assembled, with all components in place, and frame kits usually have the weather strips already in place.
What are the parts of an external door frame?
Head - The head of the frame is the horizontal piece across the top. It will usually have a stop moulded or rebated into it, where the door touches the frame when its closed. There will also be a groove for a weather strip, or the weather strip may already be installed.
The head of the frame is the horizontal piece across the top. It will usually have a stop moulded or rebated into it, where the door touches the frame when its closed. There will also be a groove for a weather strip, or the weather strip may already be installed.
Jambs - The jambs are the vertical side pieces of the frame. They also have stops moulded or rebated into them and they will also have weather strips. The weather strips on the frame create an effective seal when the door is closed to prevent draughts and leaks.
The jambs are the vertical side pieces of the frame. They also have stops moulded or rebated into them and they will also have weather strips. The weather strips on the frame create an effective seal when the door is closed to prevent draughts and leaks.
Sill - The door sill, or threshold, is particularly important on external doors as a barrier to the elements and has a weather strip or seal like the other frame pieces. The sill will often be slanted, so any water will drain away from the door. Some frame kits also include a weather bar or door sweep, which fits on the bottom of the door slab and creates a tight seal with the sill when the door is closed.
The door sill, or threshold, is particularly important on external doors as a barrier to the elements and has a weather strip or seal like the other frame pieces. The sill will often be slanted, so any water will drain away from the door. Some frame kits also include a weather bar or door sweep, which fits on the bottom of the door slab and creates a tight seal with the sill when the door is closed.
What are the different types of door frame?
Door frames can be purchased as one piece, fully constructed and ready to be fitted into an entrance opening; or they can come as individual pieces for you to assemble yourself. The ready-made frames might come separately to the door leaf or the door might be pre-hung - already attached to the frame.
Ready-assembled frames and pre-hung doors will be more expensive than ones you need to assemble yourself, but they will have been constructed by professionals and should meet the high standards needed to keep the door working correctly. External doors are often sold with ready-assembled parts, but internal doors are more regularly sold as separate pieces.
Inward opening door frames and outward opening door frames
Open door frame - The most simply constructed door frame consists of a head supported by two vertical stiles, without a sill across the bottom. These are called open door frames and are used for interior doors, where a raised threshold at the bottom of the door could hinder access.
The most simply constructed door frame consists of a head supported by two vertical stiles, without a sill across the bottom. These are called open door frames and are used for interior doors, where a raised threshold at the bottom of the door could hinder access.
Closed door frames - Exterior door frames will need to have a sill or threshold; these are called closed door frames. This horizontal piece at the bottom of the frame completes the seal around the door. The door sits on the sill when it's closed. Internal frames can also have sills, but they are usually much lower profile than external ones.
Exterior door frames will need to have a sill or threshold; these are called closed door frames. This horizontal piece at the bottom of the frame completes the seal around the door. The door sits on the sill when it's closed. Internal frames can also have sills, but they are usually much lower profile than external ones.
Frames with glazing panels - For extra light or added decorative features, you might want a door frame which includes glazing panels. There are many different options for adding glazing panels; they can be added to the side or top of frames and are made in a variety of shapes.
For extra light or added decorative features, you might want a door frame which includes glazing panels. There are many different options for adding glazing panels; they can be added to the side or top of frames and are made in a variety of shapes.
Fanlights - When the glazing panel is placed above the door it's called a fanlight or an over panel. When the jambs of a frame with an over panel reach the height of the room it will usually be called a storey frame because it reaches the next storey of the building. The horizontal part of the frame which joins the main door frame to the fanlight is usually called a transom bar.
When the glazing panel is placed above the door it's called a fanlight or an over panel. When the jambs of a frame with an over panel reach the height of the room it will usually be called a storey frame because it reaches the next storey of the building. The horizontal part of the frame which joins the main door frame to the fanlight is usually called a transom bar.
Sidelights - When a glazing panel is placed at the side of the frame it's called a sidelight. This is because glass panels set in doors are usually referred to as lights or lites. Sidelights can be either side of the door and can extend out to varying sizes, depending on the look you wish to achieve and the size of the door opening. External sidelight frame packs are available in Hardwood or Oak .
When a glazing panel is placed at the side of the frame it's called a sidelight. This is because glass panels set in doors are usually referred to as lights or lites. Sidelights can be either side of the door and can extend out to varying sizes, depending on the look you wish to achieve and the size of the door opening. External sidelight frame packs are available in Hardwood or Oak .
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Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' in the product itself. The concept can be useful in determining the effectiveness of energy-producing or energy saving devices, or the "real" replacement cost of a building, and, because energy-inputs usually entail greenhouse gas emissions, in deciding whether a product contributes to or mitigates global warming. One fundamental purpose for measuring this quantity is to compare the amount of energy produced or saved by the product in question to the amount of energy consumed in producing it.
Embodied energy is an accounting method which aims to find the sum total of the energy necessary for an entire product lifecycle. Determining what constitutes this lifecycle includes assessing the relevance and extent of energy into raw material extraction, transport, manufacture, assembly, installation, disassembly, deconstruction and/or decomposition as well as human and secondary resources.
The history of constructing a system of accounts which records the energy flows through an environment can be traced back to the origins of accounting itself. As a distinct method, it is often associated with the Physiocrat's "substance" theory of value,[1] and later the agricultural energetics of Sergei Podolinsky, a Russian physician,[2] and the ecological energetics of Vladmir Stanchinsky.[3]
The main methods of embodied energy accounting as they are used today grew out of Wassily Leontief's input-output model and are called Input-Output Embodied Energy analysis. Leontief's input-output model was in turn an adaptation of the neo-classical theory of general equilibrium with application to "the empirical study of the quantitative interdependence between interrelated economic activities".[4] According to Tennenbaum[5] Leontief's Input-Output method was adapted to embodied energy analysis by Hannon[6] to describe ecosystem energy flows. Hannon's adaptation tabulated the total direct and indirect energy requirements (the energy intensity) for each output made by the system. The total amount of energies, direct and indirect, for the entire amount of production was called the embodied energy.
Embodied energy analysis is interested in what energy goes to supporting a consumer, and so all energy depreciation is assigned to the final demand of consumer. Different methodologies use different scales of data to calculate energy embodied in products and services of nature and human civilization. International consensus on the appropriateness of data scales and methodologies is pending. This difficulty can give a wide range in embodied energy values for any given material. In the absence of a comprehensive global embodied energy public dynamic database, embodied energy calculations may omit important data on, for example, the rural road/highway construction and maintenance needed to move a product, marketing, advertising, catering services, non-human services and the like. Such omissions can be a source of significant methodological error in embodied energy estimations.[7] Without an estimation and declaration of the embodied energy error, it is difficult to calibrate the sustainability index, and so the value of any given material, process or service to environmental and economic processes.
The SBTool, UK Code for Sustainable Homes was, and USA LEED still is, a method in which the embodied energy of a product or material is rated, along with other factors, to assess a building's environmental impact. Embodied energy is a concept for which scientists have not yet agreed absolute universal values because there are many variables to take into account, but most agree that products can be compared to each other to see which has more and which has less embodied energy. Comparative lists (for an example, see the University of Bath Embodied Energy & Carbon Material Inventory[8]) contain average absolute values, and explain the factors which have been taken into account when compiling the lists.
Typical embodied energy units used are MJ/kg (megajoules of energy needed to make a kilogram of product), tCO 2 (tonnes of carbon dioxide created by the energy needed to make a kilogram of product). Converting MJ to tCO 2 is not straightforward because different types of energy (oil, wind, solar, nuclear and so on) emit different amounts of carbon dioxide, so the actual amount of carbon dioxide emitted when a product is made will be dependent on the type of energy used in the manufacturing process. For example, the Australian Government[9] gives a global average of 0.098 tCO 2 = 1 GJ. This is the same as 1 MJ = 0.098 kgCO 2 = 98 gCO 2 or 1 kgCO 2 = 10.204 MJ.
In the 2000s drought conditions in Australia have generated interest in the application of embodied energy analysis methods to water. This has led to use of the concept of embodied water.[10]
A range of databases exist for quantifying the embodied energy of goods and services, including materials and products. These are based on a range of different data sources, with variations in geographic and temporal relevance and system boundary completeness. One such database is the Environmental Performance in Construction (EPiC) Database developed at The University of Melbourne, which includes embodied energy data for over 250 mainly construction materials. This database also includes values for embodied water and greenhouse gas emissions.[11] The main reason for differences in embodied energy data between databases is due to the source of data and methodology used in their compilation. Bottom-up 'process' data is typically sourced from product manufacturers and suppliers. While this data is generally more reliable and specific to particular products, the methodology used to collect process data typically results in much of the embodied energy of a product being excluded, mainly due to the time, costs and complexity of data collection. Top-down environmentally-extended input-output (EEIO) data, based on national statistics can be used to fill these data gaps. While EEIO analysis of products can be useful on its own for initial scoping of embodied energy, it is generally much less reliable than process data and rarely relevant for a specific product or material. Hence, hybrid methods for quantifying embodied energy have been developed,[12] using available process data and filling any data gaps with EEIO data. Databases that rely on this hybrid approach, such as The University of Melbourne's EPiC Database,[13] provide a more comprehensive assessment of the embodied energy of products and materials.
Selected data from the Inventory of Carbon and Energy ('ICE') prepared by the University of Bath (UK) [8]
Theoretically, embodied energy stands for the energy used to extract materials from mines, to manufacture vehicles, assemble, transport, maintain, transform them and to transport energy, and ultimately to recycle these vehicles. Besides, the energy needed to build and maintain transport networks, whether road or rail, should be taken into account as well. The process to be implemented is so complex that no one dares to put forward a figure.
According to the fr:Institut du dveloppement durable et des relations internationales, in the field of transportation, "it is striking to note that we consume more embodied energy in our transportation expenditures than direct energy [...]. Put in other words, we consume less energy to move around in our personal vehicles than we consume the energy we need to produce, sell and transport the cars, trains or buses we use ".[14]
Jean-Marc Jancovici advocates a carbon footprint analysis of any transportation infrastructure project, prior to its construction.[15]
The embodied energy contents of a Volkswagen Golf A3 car is 18 000 kWh, the electric energy produced by roughly 9 tons of coal
According to Volkswagen, the embodied energy contents of a Golf A3 with a petrol engine amounts to 18 000 kWh (i.e. 12% of 545 GJ as shown in the report[16]). A Golf A4 (equipped with a turbocharged direct injection) will show an embodied energy amounting to 22 000 kWh (i.e. 15% of 545 GJ as shown in the report[16]). According to the French energy and environment agency ADEME [17] a motor car has an embodied energy contents of 20 800 kWh whereas an electric vehicle shows an embodied energy contents amounting to 34 700 kWh.
An electric car has a higher embodied energy than a combustion engine one, owing to the battery and electronics. According to Science & Vie, the embodied energy of batteries is so high that rechargeable hybrid cars constitute the most appropriate solution,[18] with their batteries smaller than those of an all-electric car.
As regards energy itself, the factor energy returned on energy invested (EROEI) of fuel can be estimated at 8, which means that to some amount of useful energy provided by fuel should be added 1/7 of that amount in embodied energy of the fuel. In other words, the fuel consumption should be augmented by 14.3% due to the fuel EROEI.
According to some authors, to produce 6 liters of petrol requires 42 kWh of embodied energy (which corresponds to approximately 4.2 liters of petrol in terms of energy content).[19]
We have to work here with figures, which prove still more difficult to obtain. In the case of road construction, the embodied energy would amount to 1/18 of the fuel consumption (i.e. 6%).[20]
Treloar, et al. have estimated the embodied energy in an average automobile in Australia as 0.27 terajoules (i.e. 75 000 kWh) as one component in an overall analysis of the energy involved in road transportation.[21]
The typical lifespan of a house in Japan is fewer than 30 years[22]
Although most of the focus for improving energy efficiency in buildings has been on their operational emissions, it is estimated that about 30% of all energy consumed throughout the lifetime of a building can be in its embodied energy (this percentage varies based on factors such as age of building, climate, and materials). In the past, this percentage was much lower, but as much focus has been placed on reducing operational emissions (such as efficiency improvements in heating and cooling systems), the embodied energy contribution has come much more into play. Examples of embodied energy include: the energy used to extract raw resources, process materials, assemble product components, transport between each step, construction, maintenance and repair, deconstruction and disposal. As such, it is important to employ a whole-life carbon accounting framework in analyzing the carbon emissions in buildings.[23]
EROEI (Energy Returned On Energy Invested) provides a basis for evaluating the embodied energy due to energy.
Final energy has to be multiplied by 1 EROEI-1 {\displaystyle {\frac {\hbox{1}}{\hbox{EROEI-1}}}} in order to get the embodied energy.
Given an EROEI amounting to eight e.g., a seventh of the final energy corresponds to the embodied energy.
Not only that, for really obtaining overall embodied energy, embodied energy due to the construction and maintenance of power plants should be taken into account, too. Here, figures are badly needed.
In the BP Statistical Review of World Energy June 2018, toe are converted into kWh "on the basis of thermal equivalence assuming 38% conversion efficiency in a modern thermal power station".
In France, by convention, the ratio between primary energy and final energy in electricity amounts to 2.58,[24] corresponding to an efficiency of 38.8%.
In Germany, on the contrary, because of the swift development of the renewable energies, the ratio between primary energy and final energy in electricity amounts to only 1.8,[25] corresponding to an efficiency of 55.5%.
According to EcoPassenger,[26] overall electricity efficiency would amount to 34 % in the UK , 36 % in Germany and 29 % in France.[27]
According to association ngaWatt, embodied energy related to digital services amounted to 3.5 TWh/a for networks and 10.0 TWh/a for data centres (half for the servers per se, i. e. 5 TWh/a, and the other half for the buildings in which they are housed, i. e. 5 TWh/a), figures valid in France, in 2015. The organization is optimistic about the evolution of the energy consumption in the digital field, underlining the technical progress being made.[28] The Shift Project, chaired by Jean-Marc Jancovici, contradicts the optimistic vision of the association ngaWatt, and notes that the digital energy footprint is growing at 9% per year.[29]
^ a b G.P.Hammond and C.I.Jones (2006) Embodied energy and carbon footprint database, Department of Mechanical Engineering, University of Bath, United Kingdom
^ McCormack, M.; Treloar, G.J.; Palmowski, L.; Crawford, R. (2007). "Modelling direct and indirect water requirements of construction". Building Research and Information. 35 (2): 156162. doi:10.1080/09613210601125383. S2CID 109032580.
^ Crawford, R.H.; Stephan, A.; Prideaux, F. (2019). "Environmental Performance in Construction (EPiC) Database". The University of Melbourne. doi:10.26188/5dc228ef98c5a. Cite journal requires (help)
^ Crawford, R.H.; Bontinck, P.-A.; Stephan, A.; Wiedmann, T.; Yu, M. (2018). "Hybrid life cycle inventory methods A review". Journal of Cleaner Production. 172: 12731288. doi:10.1016/j.jclepro.2017.10.176. hdl:11343/194165.
^ Crawford, R.H.; Stephan, A.; Prideaux, F. (2019). "Environmental Performance in Construction (EPiC) Database". The University of Melbourne. doi:10.26188/5dc228ef98c5a. Cite journal requires (help)
^ Treloar, Graham; Crawford, Robert (2004). "Hybrid Life-Cycle Inventory for Road Construction and Use". Journal of Construction Engineering and Management. 130 (1): 4349. doi:10.1061/(ASCE)0733-9364(2004)130:1(43).
^ Ibn-Mohammed, T.; Greenough, R.; Taylor, S.; Ozawa-Meida, L.; Acquaye, A. (1 November 2013). "Operational vs. embodied emissions in buildingsA review of current trends". Energy and Buildings. 66: 232245. doi:10.1016/j.enbuild.2013.07.026.
Clark, D.H.; Treloar, G.J.; Blair, R. (2003). "Estimating the increasing cost of commercial buildings in Australia due to greenhouse emissions trading". In Yang, J.; Brandon, P.S.; Sidwell, A.C. (eds.). Proceedings of the CIB 2003 International Conference on Smart and Sustainable Built Environment, Brisbane, Australia. hdl:10536/DRO/DU:30009596. ISBN 978-1741070415. OCLC 224896901.
Crawford, R.H. (2005). "Validation of the Use of Input-Output Data for Embodied Energy Analysis of the Australian Construction Industry". Journal of Construction Research. 6 (1): 7190. doi:10.1142/S1609945105000250.
Lenzen, M. (2001). "Errors in conventional and input-output-based life-cycle inventories". Journal of Industrial Ecology. 4 (4): 127148. doi:10.1162/10881980052541981.
Lenzen, M.; Treloar, G.J. (February 2002). "Embodied energy in buildings: wood versus concrete-reply to Brjesson and Gustavsson". Energy Policy. 30 (3): 249255. doi:10.1016/S0301-4215(01)00142-2.
Treloar, G.J. (1997). "Extracting Embodied Energy Paths from Input-Output Tables: Towards an Input-Output-based Hybrid Energy Analysis Method". Economic Systems Research. 9 (4): 375391. doi:10.1080/09535319700000032.
Treloar, Graham J. (1998). A comprehensive embodied energy analysis framework (Ph.D.). Deakin University. hdl:10536/DRO/DU:30023444.
Treloar, G.J.; Love, P.E.D.; Holt, G.D. (2001). "Using national input-output data for embodied energy analysis of individual residential buildings". Construction Management and Economics. 19 (1): 4961. doi:10.1080/014461901452076. S2CID 110124981.
Energy storage - The Llyn Stwlan dam of the Ffestiniog Pumped Storage Scheme in Wales. The lower power station has four water turbines which can generate a total of 360 MW of electricity for several hours, an example of artificial energy storage and conversion.
The Llyn Stwlan dam of the Ffestiniog Pumped Storage Scheme in Wales. The lower power station has four water turbines which can generate a total of 360 MW of electricity for several hours, an example of artificial energy storage and conversion.
Energy storage is the capture of energy produced at one time for use at a later time[1] to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an accumulator or battery. Energy comes in multiple forms including radiation, chemical, gravitational potential, electrical potential, electricity, elevated temperature, latent heat and kinetic. Energy storage involves converting energy from forms that are difficult to store to more conveniently or economically storable forms.
Some technologies provide short-term energy storage, while others can endure for much longer. Bulk energy storage is currently dominated by hydroelectric dams, both conventional as well as pumped. Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid.
Common examples of energy storage are the rechargeable battery, which stores chemical energy readily convertible to electricity to operate a mobile phone; the hydroelectric dam, which stores energy in a reservoir as gravitational potential energy; and ice storage tanks, which store ice frozen by cheaper energy at night to meet peak daytime demand for cooling. Fossil fuels such as coal and gasoline store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels. Food (which is made by the same process as fossil fuels) is a form of energy stored in chemical form.
In the 20th century grid, electrical power was largely generated by burning fossil fuel. When less power was required, less fuel was burned.[2] Hydropower, a mechanical energy storage method, is the most widely adopted mechanical energy storage, and has been in use for centuries. Large hydropower dams have been energy storage sites for more than one hundred years.[3] Concerns with air pollution, energy imports, and global warming have spawned the growth of renewable energy such as solar and wind power.[2] Wind power is uncontrolled and may be generating at a time when no additional power is needed. Solar power varies with cloud cover and at best is only available during daylight hours, while demand often peaks after sunset (see duck curve). Interest in storing power from these intermittent sources grows as the renewable energy industry begins to generate a larger fraction of overall energy consumption.[4]
Off grid electrical use was a niche market in the 20th century, but in the 21st century, it has expanded. Portable devices are in use all over the world. Solar panels are now common in the rural settings worldwide. Access to electricity is now a question of economics and financial viability, and not solely on technical aspects. Electric vehicles are gradually replacing combustion-engine vehicles. However, powering long-distance transportation without burning fuel remains in development.
Energy can be stored in water pumped to a higher elevation using pumped storage methods or by moving solid matter to higher locations (gravity batteries). Other commercial mechanical methods include compressing air and flywheels that convert electric energy into internal energy or kinetic energy and then back again when electrical demand peaks.
Hydroelectric dams with reservoirs can be operated to provide electricity at times of peak demand. Water is stored in the reservoir during periods of low demand and released when demand is high. The net effect is similar to pumped storage, but without the pumping loss.
While a hydroelectric dam does not directly store energy from other generating units, it behaves equivalently by lowering output in periods of excess electricity from other sources. In this mode, dams are one of the most efficient forms of energy storage, because only the timing of its generation changes. Hydroelectric turbines have a start-up time on the order of a few minutes.[5]
At times of low electrical demand, excess generation capacity is used to pump water from a lower source into a higher reservoir. When demand grows, water is released back into a lower reservoir (or waterway or body of water) through a turbine, generating electricity. Reversible turbine-generator assemblies act as both a pump and turbine (usually a Francis turbine design). Nearly all facilities use the height difference between two water bodies. Pure pumped-storage plants shift the water between reservoirs, while the "pump-back" approach is a combination of pumped storage and conventional hydroelectric plants that use natural stream-flow.
Compressed air energy storage (CAES) uses surplus energy to compress air for subsequent electricity generation.[11] Small-scale systems have long been used in such applications as propulsion of mine locomotives. The compressed air is stored in an underground reservoir, such as a salt dome.
Compressed-air energy storage (CAES) plants can bridge the gap between production volatility and load. CAES storage addresses the energy needs of consumers by effectively providing readily available energy to meet demand. Renewable energy sources like wind and solar energy vary. So at times when they provide little power, they need to be supplemented with other forms of energy to meet energy demand. Compressed-air energy storage plants can take in the surplus energy output of renewable energy sources during times of energy over-production. This stored energy can be used at a later time when demand for electricity increases or energy resource availability decreases.[12]
Compression of air creates heat; the air is warmer after compression. Expansion requires heat. If no extra heat is added, the air will be much colder after expansion. If the heat generated during compression can be stored and used during expansion, efficiency improves considerably.[13] A CAES system can deal with the heat in three ways. Air storage can be adiabatic, diabatic, or isothermal. Another approach uses compressed air to power vehicles.[14][15]
Flywheel energy storage (FES) works by accelerating a rotor (a flywheel) to a very high speed, holding energy as rotational energy. When energy is added the rotational speed of the flywheel increases, and when energy is extracted, the speed declines, due to conservation of energy.
Most FES systems use electricity to accelerate and decelerate the flywheel, but devices that directly use mechanical energy are under consideration.[16]
FES systems have rotors made of high strength carbon-fiber composites, suspended by magnetic bearings and spinning at speeds from 20,000 to over 50,000 revolutions per minute (rpm) in a vacuum enclosure.[17] Such flywheels can reach maximum speed ("charge") in a matter of minutes. The flywheel system is connected to a combination electric motor/generator.
FES systems have relatively long lifetimes (lasting decades with little or no maintenance;[17] full-cycle lifetimes quoted for flywheels range from in excess of 105, up to 107, cycles of use),[18] high specific energy (100130 Wh/kg, or 360500 kJ/kg)[18][19] and power density.
Changing the altitude of solid masses can store or release energy via an elevating system driven by an electric motor/generator. Studies suggest energy can begin to be released with as little as 1 second warning, making the method a useful supplemental feed into an electricity grid to balance load surges.[20]
Efficiencies can be as high as 85% recovery of stored energy.[21]
This can be achieved by siting the masses inside old vertical mine shafts or in specially constructed towers where the heavy weights are winched up to store energy and allowed a controlled descent to release it. At 2020 a prototype vertical store is being built in Edinburgh, Scotland [22]
using rails[26][27] and cranes[21] to move concrete weights up and down;
using high-altitude solar-powered balloon platforms supporting winches to raise and lower solid masses slung underneath them,[28]
using winches supported by an ocean barge to take advantage of a 4 km (13,000 ft) elevation difference between the sea surface and the seabed,[29]
Sensible heat storage take advantage of sensible heat in a material to store energy.[30]
Seasonal thermal energy storage (STES) allows heat or cold to be used months after it was collected from waste energy or natural sources. The material can be stored in contained aquifers, clusters of boreholes in geological substrates such as sand or crystalline bedrock, in lined pits filled with gravel and water, or water-filled mines.[31] Seasonal thermal energy storage (STES) projects often have paybacks in four to six years.[32] An example is Drake Landing Solar Community in Canada, for which 97% of the year-round heat is provided by solar-thermal collectors on the garage roofs, with a borehole thermal energy store (BTES) being the enabling technology.[33][34][35] In Braedstrup, Denmark, the community's solar district heating system also uses STES, at a temperature of 65 C (149 F). A heat pump, which is run only when there is surplus wind power available on the national grid, is used to raise the temperature to 80 C (176 F) for distribution. When surplus wind generated electricity is not available, a gas-fired boiler is used. Twenty percent of Braedstrup's heat is solar.[36]
Latent heat thermal energy storage systems work by transferring heat to or from a material to change its phase. A phase-change is the melting, solidifying, vaporizing or liquifying. Such a material is called a phase change material (PCM). Materials used in LHTESs often have a high latent heat so that at their specific temperature, the phase change absorbs a large amount of energy, much more than sensible heat.[37]
A steam accumulator is a type of LHTES where the phase change is between liquid and gas and uses the latent heat of vaporization of water. Ice storage air conditioning systems use off-peak electricity to store cold by freezing water into ice. The stored cold in ice releases during melting process and can be used for cooling at peak hours.
Air can be liquefied by cooling using electricity and stored as a cryogen with existing technologies. The liquid air can then be expanded through a turbine and the energy recovered as electricity. The system was demonstrated at a pilot plant in the UK in 2012.[38] In 2019, Highview announced plans to build a 50 MW in the North of England and northern Vermont, with the proposed facility able to store five to eight hours of energy, for a 250-400 MWh storage capacity.[39]
Electrical energy can be stored in heat storage by resistive heating or heat pumps, and the stored heat can be converted back to electricity via Rankine cycle or Brayton cycle.[40] This technology has been studied to retrofit exising coal-fired power plants into fossil-fuel free generation systems.[41] Coal-fired boilers are replaced by high-temperature heat storage which is charged by excess electricity from variable renewable energy sources. In 2020, German Aerospace Center starts to construct the world's first large-scale Carnot battery system, which has 1,000 MWh storage capacity.[42]
A rechargeable battery comprises one or more electrochemical cells. It is known as a 'secondary cell' because its electrochemical reactions are electrically reversible. Rechargeable batteries come in many shapes and sizes, ranging from button cells to megawatt grid systems.
Rechargeable batteries have lower total cost of use and environmental impact than non-rechargeable (disposable) batteries. Some rechargeable battery types are available in the same form factors as disposables. Rechargeable batteries have higher initial cost but can be recharged very cheaply and used many times.
Common rechargeable battery chemistries include: - Leadacid battery: Lead acid batteries hold the largest market share of electric storage products. A single cell produces about 2V when charged. In the charged state the metallic lead negative electrode and the lead sulfate positive electrode are immersed in a dilute sulfuric acid (H2SO4) electrolyte. In the discharge process electrons are pushed out of the cell as lead sulfate is formed at the negative electrode while the electrolyte is reduced to water.
Leadacid battery: Lead acid batteries hold the largest market share of electric storage products. A single cell produces about 2V when charged. In the charged state the metallic lead negative electrode and the lead sulfate positive electrode are immersed in a dilute sulfuric acid (H2SO4) electrolyte. In the discharge process electrons are pushed out of the cell as lead sulfate is formed at the negative electrode while the electrolyte is reduced to water.
Lead-acid battery technology has been developed extensively. Upkeep requires minimal labor and its cost is low. The battery's available energy capacity is subject to a quick discharge resulting in a low life span and low energy density.[43]
Nickelcadmium battery (NiCd): Uses nickel oxide hydroxide and metallic cadmium as electrodes. Cadmium is a toxic element, and was banned for most uses by the European Union in 2004. Nickelcadmium batteries have been almost completely replaced by nickelmetal hydride (NiMH) batteries.
Nickelmetal hydride battery (NiMH): First commercial types were available in 1989.[44] These are now a common consumer and industrial type. The battery has a hydrogen-absorbing alloy for the negative electrode instead of cadmium.
A flow battery works by passing a solution over a membrane where ions are exchanged to charge or discharge the cell. Cell voltage is chemically determined by the Nernst equation and ranges, in practical applications, from 1.0 V to 2.2 V. Storage capacity depends on the volume of solution. A flow battery is technically akin both to a fuel cell and an electrochemical accumulator cell. Commercial applications are for long half-cycle storage such as backup grid power.
One of a fleet of electric capabuses powered by supercapacitors, at a quick-charge station-bus stop, in service during Expo 2010 Shanghai China. Charging rails can be seen suspended over the bus.
Supercapacitors bridge the gap between conventional capacitors and rechargeable batteries. They store the most energy per unit volume or mass (energy density) among capacitors. They support up to 10,000 farads/1.2 Volt,[48] up to 10,000 times that of electrolytic capacitors, but deliver or accept less than half as much power per unit time (power density).[45]
While supercapacitors have specific energy and energy densities that are approximately 10% of batteries, their power density is generally 10 to 100 times greater. This results in much shorter charge/discharge cycles. Also, they tolerate many more charge-discharge cycles than batteries.
Supercapacitors have many applications, including: - Power for cars, buses, trains, cranes and elevators, including energy recovery from braking, short-term energy storage and burst-mode power delivery
Power for cars, buses, trains, cranes and elevators, including energy recovery from braking, short-term energy storage and burst-mode power delivery
In the first method, hydrogen is injected into the natural gas grid or is used for transportation. The second method is to combine the hydrogen with carbon dioxide to produce methane using a methanation reaction such as the Sabatier reaction, or biological methanation, resulting in an extra energy conversion loss of 8%. The methane may then be fed into the natural gas grid. The third method uses the output gas of a wood gas generator or a biogas plant, after the biogas upgrader is mixed with the hydrogen from the electrolyzer, to upgrade the quality of the biogas.
The element hydrogen can be a form of stored energy. Hydrogen can produce electricity via a hydrogen fuel cell.
At penetrations below 20% of the grid demand, renewables do not severely change the economics; but beyond about 20% of the total demand,[49] external storage becomes important.[50] If these sources are used to make ionic hydrogen, they can be freely expanded. A 5-year community-based pilot program using wind turbines and hydrogen generators began in 2007 in the remote community of Ramea, Newfoundland and Labrador.[51] A similar project began in 2004 on Utsira, a small Norwegian island.
Energy losses involved in the hydrogen storage cycle come from the electrolysis of water, liquification or compression of the hydrogen and conversion to electricity.[52]
About 50 kWh (180 MJ) of solar energy is required to produce a kilogram of hydrogen, so the cost of the electricity is crucial. At $0.03/kWh, a common off-peak high-voltage line rate in the United States, hydrogen costs $1.50 per kilogram for the electricity, equivalent to $1.50/gallon for gasoline. Other costs include the electrolyzer plant, hydrogen compressors or liquefaction, storage and transportation.[citation needed]
Hydrogen can also be produced from aluminum and water by stripping aluminum's naturally-occurring aluminum oxide barrier and introducing it to water. This method is beneficial because recycled aluminum cans can be used to generate hydrogen, however systems to harness this option have not been commercially developed and are much more complex than electrolysis systems.[53] Common methods to strip the oxide layer include caustic catalysts such as sodium hydroxide and alloys with gallium, mercury and other metals.[54]
Powerpaste is a magnesium and hydrogen -based fluid gel that releases hydrogen when reacting with water. It was invented, patented and is being developed by the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) of the Fraunhofer-Gesellschaft. Powerpaste is made by combining magnesium powder with hydrogen to form magnesium hydride in a process conducted at 350 C and five to six times atmospheric pressure. An ester and a metal salt are then added to make the finished product. Fraunhofer states that they are building a production plant slated to start production in 2021, which will produce 4 tons of Powerpaste annually.[59] Fraunhofer has patented their invention in the United States and EU.[60] Fraunhofer claims that Powerpaste is able to store hydrogen energy at 10 times the energy density of a lithium battery of a similar dimension and is safe and convenient for automotive situations.[59]
Methane is the simplest hydrocarbon with the molecular formula CH4. Methane is more easily stored and transported than hydrogen. Storage and combustion infrastructure (pipelines, gasometers, power plants) are mature.
Synthetic natural gas (syngas or SNG) can be created in a multi-step process, starting with hydrogen and oxygen. Hydrogen is then reacted with carbon dioxide in a Sabatier process, producing methane and water. Methane can be stored and later used to produce electricity. The resulting water is recycled, reducing the need for water. In the electrolysis stage, oxygen is stored for methane combustion in a pure oxygen environment at an adjacent power plant, eliminating nitrogen oxides.
Methane combustion produces carbon dioxide (CO2) and water. The carbon dioxide can be recycled to boost the Sabatier process and water can be recycled for further electrolysis. Methane production, storage and combustion recycles the reaction products.
The CO2 has economic value as a component of an energy storage vector, not a cost as in carbon capture and storage.
Power to liquid is similar to power to gas except that the hydrogen is converted into liquids such as methanol or ammonia. These are easier to handle than gases, and requires fewer safety precautions than hydrogen. They can be used for transportation, including aircraft, but also for industrial purposes or in the power sector.[61]
Various biofuels such as biodiesel, vegetable oil, alcohol fuels, or biomass can replace fossil fuels. Various chemical processes can convert the carbon and hydrogen in coal, natural gas, plant and animal biomass and organic wastes into short hydrocarbons suitable as replacements for existing hydrocarbon fuels. Examples are FischerTropsch diesel, methanol, dimethyl ether and syngas. This diesel source was used extensively in World War II in Germany, which faced limited access to crude oil supplies. South Africa produces most of the country's diesel from coal for similar reasons.[62] A long term oil price above US$35/bbl may make such large scale synthetic liquid fuels economical.
Aluminum has been proposed as an energy store by a number of researchers. Its electrochemical equivalent (8.04 Ah/cm3) is nearly four times greater than that of lithium (2.06 Ah/cm3).[63] Energy can be extracted from aluminum by reacting it with water to generate hydrogen.[64] However, it must first be stripped of its natural oxide layer, a process which requires pulverization,[65] chemical reactions with caustic substances, or alloys.[54] The byproduct of the reaction to create hydrogen is aluminum oxide, which can be recycled into aluminum with the HallHroult process, making the reaction theoretically renewable.[54] If the Hall-Heroult Process is run using solar or wind power, aluminum could be used to store the energy produced at higher efficiency than direct solar electrolysis.[66]
The organic compound norbornadiene converts to quadricyclane upon exposure to light, storing solar energy as the energy of chemical bonds. A working system has been developed in Sweden as a molecular solar thermal system.[70]
This mylar-film, oil-filled capacitor has very low inductance and low resistance, to provide the high-power (70 megawatts) and the very high speed (1.2 microsecond) discharges needed to operate a dye laser.
A capacitor (originally known as a 'condenser') is a passive two-terminal electrical component used to store energy electrostatically. Practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e., insulator). A capacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary battery, or like other types of rechargeable energy storage system.[71] Capacitors are commonly used in electronic devices to maintain power supply while batteries change. (This prevents loss of information in volatile memory.) Conventional capacitors provide less than 360 joules per kilogram, while a conventional alkaline battery has a density of 590 kJ/kg.
Capacitors store energy in an electrostatic field between their plates. Given a potential difference across the conductors (e.g., when a capacitor is attached across a battery), an electric field develops across the dielectric, causing positive charge (+Q) to collect on one plate and negative charge (-Q) to collect on the other plate. If a battery is attached to a capacitor for a sufficient amount of time, no current can flow through the capacitor. However, if an accelerating or alternating voltage is applied across the leads of the capacitor, a displacement current can flow. Besides capacitor plates, charge can also be stored in a dielectric layer.[72]
Capacitance is greater given a narrower separation between conductors and when the conductors have a larger surface area. In practice, the dielectric between the plates emits a small amount of leakage current and has an electric field strength limit, known as the breakdown voltage. However, the effect of recovery of a dielectric after a high-voltage breakdown holds promise for a new generation of self-healing capacitors.[73][74] The conductors and leads introduce undesired inductance and resistance.
Research is assessing the quantum effects of nanoscale capacitors[75] for digital quantum batteries.[76][77]
Superconducting magnetic energy storage (SMES) systems store energy in a magnetic field created by the flow of direct current in a superconducting coil that has been cooled to a temperature below its superconducting critical temperature. A typical SMES system includes a superconducting coil, power conditioning system and refrigerator. Once the superconducting coil is charged, the current does not decay and the magnetic energy can be stored indefinitely.[78]
The stored energy can be released to the network by discharging the coil. The associated inverter/rectifier accounts for about 23% energy loss in each direction. SMES loses the least amount of electricity in the energy storage process compared to other methods of storing energy. SMES systems offer round-trip efficiency greater than 95%.[79]
Due to the energy requirements of refrigeration and the cost of superconducting wire, SMES is used for short duration storage such as improving power quality. It also has applications in grid balancing.[78]
The classic application before the industrial revolution was the control of waterways to drive water mills for processing grain or powering machinery. Complex systems of reservoirs and dams were constructed to store and release water (and the potential energy it contained) when required.[80]
Home energy storage is expected to become increasingly common given the growing importance of distributed generation of renewable energies (especially photovoltaics) and the important share of energy consumption in buildings.[81] To exceed a self-sufficiency of 40% in a household equipped with photovoltaics, energy storage is needed.[81] Multiple manufacturers produce rechargeable battery systems for storing energy, generally to hold surplus energy from home solar or wind generation. Today, for home energy storage, Li-ion batteries are preferable to lead-acid ones given their similar cost but much better performance.[82]
Tesla Motors produces two models of the Tesla Powerwall. One is a 10 kWh weekly cycle version for backup applications and the other is a 7 kWh version for daily cycle applications.[83] In 2016, a limited version of the Tesla Powerpack 2 cost $398(US)/kWh to store electricity worth 12.5 cents/kWh (US average grid price) making a positive return on investment doubtful unless electricity prices are higher than 30 cents/kWh.[84]
RoseWater Energy produces two models of the "Energy & Storage System", the HUB 120[85] and SB20.[86] Both versions provide 28.8 kWh of output, enabling it to run larger houses or light commercial premises, and protecting custom installations. The system provides five key elements into one system, including providing a clean 60 Hz Sine wave, zero transfer time, industrial-grade surge protection, renewable energy grid sell-back (optional), and battery backup.[87][88]
Enphase Energy announced an integrated system that allows home users to store, monitor and manage electricity. The system stores 1.2 kWh of energy and 275W/500W power output.[89]
Storing wind or solar energy using thermal energy storage though less flexible, is considerably cheaper than batteries. A simple 52-gallon electric water heater can store roughly 12 kWh of energy for supplementing hot water or space heating.[90]
For purely financial purposes in areas where net metering is available, home generated electricity may be sold to the grid through a grid-tie inverter without the use of batteries for storage.
Construction of the Salt Tanks which provide efficient thermal energy storage[91] so that electricity can be generated after the sun goes down, and output can be scheduled to meet demand.[92] The 280 MW Solana Generating Station is designed to provide six hours of storage. This allows the plant to generate about 38% of its rated capacity over the course of a year.[93]
The largest source and the greatest store of renewable energy is provided by hydroelectric dams. A large reservoir behind a dam can store enough water to average the annual flow of a river between dry and wet seasons. A very large reservoir can store enough water to average the flow of a river between dry and wet years. While a hydroelectric dam does not directly store energy from intermittent sources, it does balance the grid by lowering its output and retaining its water when power is generated by solar or wind. If wind or solar generation exceeds the region's hydroelectric capacity, then some additional source of energy is needed.
Many renewable energy sources (notably solar and wind) produce variable power.[95] Storage systems can level out the imbalances between supply and demand that this causes. Electricity must be used as it is generated or converted immediately into storable forms.[96]
The main method of electrical grid storage is pumped-storage hydroelectricity. Areas of the world such as Norway, Wales, Japan and the US have used elevated geographic features for reservoirs, using electrically powered pumps to fill them. When needed, the water passes through generators and converts the gravitational potential of the falling water into electricity.[95] Pumped storage in Norway, which gets almost all its electricity from hydro, has currently a capacity of 1.4 GW but since the total installed capacity is nearly 32 GW and 75% of that is regulable, it can be expanded significantly.[97]
In 2011, the Bonneville Power Administration in Northwestern United States created an experimental program to absorb excess wind and hydro power generated at night or during stormy periods that are accompanied by high winds. Under central control, home appliances absorb surplus energy by heating ceramic bricks in special space heaters to hundreds of degrees and by boosting the temperature of modified hot water heater tanks. After charging, the appliances provide home heating and hot water as needed. The experimental system was created as a result of a severe 2010 storm that overproduced renewable energy to the extent that all conventional power sources were shut down, or in the case of a nuclear power plant, reduced to its lowest possible operating level, leaving a large area running almost completely on renewable energy.[101][102]
Another advanced method used at the former Solar Two project in the United States and the Solar Tres Power Tower in Spain uses molten salt to store thermal energy captured from the sun and then convert it and dispatch it as electrical power. The system pumps molten salt through a tower or other special conduits to be heated by the sun. Insulated tanks store the solution. Electricity is produced by turning water to steam that is fed to turbines.
Since the early 21st century batteries have been applied to utility scale load-leveling and frequency regulation capabilities.[95]
In vehicle-to-grid storage, electric vehicles that are plugged into the energy grid can deliver stored electrical energy from their batteries into the grid when needed.
Thermal energy storage (TES) can be used for air conditioning.[103] It is most widely used for cooling single large buildings and/or groups of smaller buildings. Commercial air conditioning systems are the biggest contributors to peak electrical loads. In 2009, thermal storage was used in over 3,300 buildings in over 35 countries. It works by chilling material at night and using the chilled material for cooling during the hotter daytime periods.[98]
The most popular technique is ice storage, which requires less space than water and is cheaper than fuel cells or flywheels. In this application, a standard chiller runs at night to produce an ice pile. Water circulates through the pile during the day to chill water that would normally be the chiller's daytime output.
A partial storage system minimizes capital investment by running the chillers nearly 24 hours a day. At night, they produce ice for storage and during the day they chill water. Water circulating through the melting ice augments the production of chilled water. Such a system makes ice for 16 to 18 hours a day and melts ice for six hours a day. Capital expenditures are reduced because the chillers can be just 40% - 50% of the size needed for a conventional, no-storage design. Storage sufficient to store half a day's available heat is usually adequate.
A full storage system shuts off the chillers during peak load hours. Capital costs are higher, as such a system requires larger chillers and a larger ice storage system.
This ice is produced when electrical utility rates are lower.[104] Off-peak cooling systems can lower energy costs. The U.S. Green Building Council has developed the Leadership in Energy and Environmental Design (LEED) program to encourage the design of reduced-environmental impact buildings. Off-peak cooling may help toward LEED Certification.[105]
Thermal storage for heating is less common than for cooling. An example of thermal storage is storing solar heat to be used for heating at night.
Latent heat can also be stored in technical phase change materials (PCMs). These can be encapsulated in wall and ceiling panels, to moderate room temperatures.
Public transport systems like trams and trolleybuses require electricity, but due to their variability in movement, a steady supply of electricity via renewable energy is challenging. Photovoltaic systems installed on the roofs of buildings can be used to power public transportation systems during periods in which there is increased demand for electricity and access to other forms of energy are not readily available.[106] Upcoming transitions in the transportation system also include e.g. ferries and airplanes, where electric power supply is investigated as an interesting alternative.[107]
Storage capacity is the amount of energy extracted from an energy storage device or system; usually measured in joules or kilowatt-hours and their multiples, it may be given in number of hours of electricity production at power plant nameplate capacity; when storage is of primary type (i.e., thermal or pumped-water), output is sourced only with the power plant embedded storage system.[110][111]
The economics of energy storage strictly depends on the reserve service requested, and several uncertainty factors affect the profitability of energy storage. Therefore, not every storage method is technically and economically suitable for the storage of several MWh, and the optimal size of the energy storage is market and location dependent.[112]
Moreover, ESS are affected by several risks, e.g.:[113]
1) Techno-economic risks, which are related to the specific technology;
2) Market risks, which are the factors that affect the electricity supply system;
3) Regulation and policy risks. - Therefore, traditional techniques based on deterministic Discounted Cash Flow (DCF) for the investment appraisal are not fully adequate to evaluate these risks and uncertainties and the investor's flexibility to deal with them. Hence, the literature recommends to assess the value of risks and uncertainties through the Real Option Analysis (ROA), which is a valuable method in uncertain contexts.[113]
Therefore, traditional techniques based on deterministic Discounted Cash Flow (DCF) for the investment appraisal are not fully adequate to evaluate these risks and uncertainties and the investor's flexibility to deal with them. Hence, the literature recommends to assess the value of risks and uncertainties through the Real Option Analysis (ROA), which is a valuable method in uncertain contexts.[113]
The economic valuation of large-scale applications (including pumped hydro storage and compressed air) considers benefits including: curtailment avoidance, grid congestion avoidance, price arbitrage and carbon-free energy delivery.[98][114][115] In one technical assessment by the Carnegie Mellon Electricity Industry Centre, economic goals could be met using batteries if their capital cost was $30 to $50 per kilowatt-hour.[98]
A metric of energy efficiency of storage is energy storage on energy invested (ESOI), which is the amount of energy that can be stored by a technology, divided by the amount of energy required to build that technology. The higher the ESOI, the better the storage technology is energetically. For lithium-ion batteries this is around 10, and for lead acid batteries it is about 2. Other forms of storage such as pumped hydroelectric storage generally have higher ESOI, such as 210.[116]
In 2013, the German Federal government allocated 200M (approximately US$270M) for research, and another 50M to subsidize battery storage in residential rooftop solar panels, according to a representative of the German Energy Storage Association.[117]
Siemens AG commissioned a production-research plant to open in 2015 at the Zentrum fr Sonnenenergie und Wasserstoff (ZSW, the German Center for Solar Energy and Hydrogen Research in the State of Baden-Wrttemberg), a university/industry collaboration in Stuttgart, Ulm and Widderstall, staffed by approximately 350 scientists, researchers, engineers, and technicians. The plant develops new near-production manufacturing materials and processes (NPMM&P) using a computerized Supervisory Control and Data Acquisition (SCADA) system. It aims to enable the expansion of rechargeable battery production with increased quality and lower cost.[118][119]
On September 27, 2017, Senators Al Franken of Minnesota and Martin Heinrich of New Mexico introduced Advancing Grid Storage Act (AGSA), which would devote more than $1 billion in research, technical assistance and grants to encourage energy storage in the United States.[122]
In the United Kingdom, some 14 industry and government agencies allied with seven British universities in May 2014 to create the SUPERGEN Energy Storage Hub in order to assist in the coordination of energy storage technology research and development.[123][124]
^ Clarke, Energy. "Energy Storage". Clarke Energy. Retrieved June 5, 2020.
^ a b Liasi, Sahand Ghaseminejad; Bathaee, Seyed Mohammad Taghi (July 30, 2019). "Optimizing microgrid using demand response and electric vehicles connection to microgrid". 2017 Smart Grid Conference (SGC). pp. 17. doi:10.1109/SGC.2017.8308873. ISBN 978-1-5386-4279-5. S2CID 3817521.
^ Keles, Dogan; Hartel, Rupert; Mst, Dominik; Fichtner, Wolf (Spring 2012). "Compressed-air energy storage power plant investments under uncertain electricity prices: an evaluation of compressed-air energy storage plants in liberalized energy markets". The Journal of Energy Markets. 5 (1): 54. doi:10.21314/JEM.2012.070. ProQuest 1037988494.
^ Layered Materials for Energy Storage and Conversion, Editors: Dongsheng Geng, Yuan Cheng, Gang Zhang , Royal Society of Chemistry, Cambridge 2019,
^ Hellstrm, G. (May 19, 2008), Large-Scale Applications of Ground-Source Heat Pumps in Sweden, IEA Heat Pump Annex 29 Workshop, Zurich.
^ Sekhara Reddy, M.C.; T., R.L.; K., D.R; Ramaiah, P.V (2015). "Enhancement of thermal energy storage system using sensible heat and latent heat storage materials". I-Manager's Journal on Mechanical Engineering. 5: 36. ProQuest 1718068707.
^ Marin S. Halper, James C. Ellenbogen (March 2006). Supercapacitors: A Brief Overview (PDF) (Technical report). MITRE Nanosystems Group. Archived from the original (PDF) on February 1, 2014. Retrieved January 20, 2014.
^ Frackowiak, Elzbieta; Bguin, Franois (2001). "Carbon materials for the electrochemical storage of energy in Capacitors". Carbon. 39 (6): 937950. doi:10.1016/S0008-6223(00)00183-4.
^ Chen, Y.; et., al. (2012). "Study on self-healing and lifetime characteristics of metallized-film capacitor under high electric field". IEEE Transactions on Plasma Science. 40 (8): 20142019. Bibcode:2012ITPS...40.2014C. doi:10.1109/TPS.2012.2200699. S2CID 8722419.
^ Hubler, A.; Osuagwu, O. (2010). "Digital quantum batteries: Energy and information storage in nanovacuum tube arrays". Complexity. 15: NA. doi:10.1002/cplx.20306.
^ a b Hassenzahl, W.V., "Applied Superconductivity: Superconductivity, An Enabling Technology For 21st Century Power Systems?", IEEE Transactions on Magnetics, pp. 14471453, Vol. 11, Iss. 1, March 2001.
^ Cheung K.Y.C; Cheung S.T.H.; Navin De Silvia; Juvonen; Singh; Woo J.J. Large-Scale Energy Storage Systems, Imperial College London: ISE2, 2002/2003.
^ Encyclopedia of technology and applied sciences. 10. New York: Marshall Cavendish. 2000. p. 1401. ISBN 076147126X. Retrieved December 31, 2020. Simple waterwheels were used in the Balkans of Europe in 100 B.C.E for powering flour mills. Elaborate Irrigation systems had been built In Egypt and Mesopotamia a thousand years before that, and it is very likely that these systems contained simple waterwheels. Waterwheels powered by a stream running underneath were common in the Roman Empire during the third and fourth centuries C.E. After the fall of the Western Roman Empire, water technology advanced further in the Middle East than in Europe, but waterwheels were commonly used to harness water as a source of power in Europe during the Middle Ages. The Doomsday Book of 1086 C.E. lists 5624 water powered mills in the southern half of England. The designs of more efficient waterwheels were brought back to Europe from the Middle East by the Crusaders and were used for grinding grain and for powering furnace bellows.
^ a b Guilherme de Oliveira e Silva; Patrick Hendrick (September 15, 2016). "Lead-acid batteries coupled with photovoltaics for increased electricity self-sufficiency in households". Applied Energy. 178: 856867. doi:10.1016/j.apenergy.2016.06.003.
^ Edwin Cartlidge (November 18, 2011). "Saving for a rainy day". Science (Vol 334). pp. 922924. Missing or empty (help)
^ Air-Conditioning, Heating and Refrigeration Institute, Fundamentals of HVAC/R, Page 1263
^ Loisel, Rodica; Mercier, Arnaud; Gatzen, Christoph; Elms, Nick; Petric, Hrvoje (2010). "Valuation framework for large scale electricity storage in a case with wind curtailment". Energy Policy. 38 (11): 73237337. doi:10.1016/j.enpol.2010.08.007.
Chen, Haisheng; Thang Ngoc Cong; Wei Yang; Chunqing Tan; Yongliang Li; Yulong Ding. Progress in electrical energy storage system: A critical review, Progress in Natural Science, accepted July 2, 2008, published in Vol. 19, 2009, pp. 291312, doi: 10.1016/j.pnsc.2008.07.014. Sourced from the National Natural Science Foundation of China and the Chinese Academy of Sciences. Published by Elsevier and Science in China Press. Synopsis: a review of electrical energy storage technologies for stationary applications. Retrieved from ac.els-cdn.com on May 13, 2014. (PDF)
Corum, Lyn. The New Core Technology: Energy storage is part of the smart grid evolution, The Journal of Energy Efficiency and Reliability, December 31, 2009. Discusses: Anaheim Public Utilities Department, lithium ion energy storage, iCel Systems, Beacon Power, Electric Power Research Institute (EPRI), ICEL, Self Generation Incentive Program, ICE Energy, vanadium redox flow, lithium Ion, regenerative fuel cell, ZBB, VRB, lead acid, CAES, and Thermal Energy Storage. (PDF)
de Oliveira e Silva, G.; Hendrick, P. (2016). "Lead-acid batteries coupled with photovoltaics for increased electricity self-sufficiency in households". Applied Energy. 178: 856867. doi:10.1016/j.apenergy.2016.06.003.
Whittingham, M. Stanley. History, Evolution, and Future Status of Energy Storage, Proceedings of the IEEE, manuscript accepted February 20, 2012, date of publication April 16, 2012; date of current version May 10, 2012, published in Proceedings of the IEEE, Vol. 100, May 13, 2012, 00189219, pp. 15181534, doi: 10.1109/JPROC.2012.219017. Retrieved from ieeexplore.ieee.org May 13, 2014. Synopsis: A discussion of the important aspects of energy storage including emerging battery technologies and the importance of storage systems in key application areas, including electronic devices, transportation, and the utility grid. (PDF)
Daz-Gonzlez, Franscisco (2016). Energy storage in power systems. United Kingdom: John Wiley & Sons. ISBN 9781118971321.
IEA-ECES - International Energy Agency - Energy Conservation through Energy Conservation programme.
A fire resistance rating typically means the duration for which a passive fire protection system can withstand a standard fire resistance test. This can be quantified simply as a measure of time, or it may entail a host of other criteria, involving other evidence of functionality or fitness for purpose.
The following depict the most commonly used international time/temperature curves:
Time/Temperature Curves used for testing the fire-resistance rating of passive fire protection systems in tunnels in Germany, The Netherlands and France.
Time/Temperature Curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in The Netherlands.
Time/Temperature Curve used for testing the fire-resistance rating of passive fire protection systems in Europe.
Time/Temperature Curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in France.
Time/Temperature Curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in Germany.
Furnace pressure is also subject to standardised tolerances for testing to obtain fire-resistance ratings. This image shows European tolerances, subject to NEN-EN 1363-1.
Furnace Temperatures for fire testing to obtain fire-resistance ratings are subject to certain tolerances. This graph shows the tolerance applicable to the European building elements / cellulosic curve.
MOAC: Mother of all curves Reprinted, with permission, from E3134-17 Standard Specification for Transportation Tunnel Structural Components and Passive Fire Protection Systems, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, http://www.astm.org."
There are many international variations for nearly countless types of products and systems, some with multiple test requirements.
Canada's Institute for Research in Construction (a part of the National Research Council and publisher of Canada's model building code - NBC) requires a special test regime for firestops for plastic pipe penetrants. Fire endurance tests for this application must be run under 50Pa positive furnace pressure in order to adequately simulate the effect of potential temperature differences between indoor and outdoor temperatures in Canada's winters. Special hoods are applied here to provide suction on the top side of a test assembly in order to reach the 50Pa pressure differential. Afterwards, a 30PSI hose-stream test may be applied.
Outdoor spray fireproofing methods that must be qualified to the hydrocarbon curve may be required to pass a host of environmental tests before any burn takes place, to minimize the likelihood of ordinary operational environments rendering a vital system component useless before it ever encounters a fire.
If critical environmental conditions are not satisfied, an assembly may not be eligible for a fire-resistance rating.
Tests for fire resistance of record protection equipment[edit]
The following classifications may be attained when testing in accordance with UL 72.[1]
This rating is the requirement in data safes and vault structures for protecting digital information on magnetic media or hard drives. Temperatures inside the protected chamber must be held below 125 F (52 C) for the time period specified, such as Class 125-2 Hour, with temperatures up to 2,000 F (1,090 C) outside the vault. The temperature reading is taken on the inside surfaces of the protective structure. Maintaining the temperature below 125 F is critical because data is lost above that temperature threshold, even if the media or hard drives appear to be intact.
This is the rating required to protect microfilm, microfiche, and other film-based information storage media. Above 150 F (65.5 C) film is distorted by the heat and information is lost. A Class 150-2 Hour vault must keep the temperature below 150 F. for at least two hours, with temperatures up to 2,000 F. (1,093.3 C) outside the vault.
This rating is the requirement for protecting paper documents. Above 350 F (176.7 C) paper is distorted by the heat and information is lost. A Class 350-4 Hour vault must keep the temperature below 350 F. for at least four hours, with temperatures up to 2,000 F. (1,093.3 C) outside the vault.
Typically, most countries use the building elements curve for residential and commercial spaces, which is nearly identical in most countries as that is what results by burning wood. The building elements curve is characterized jointly by, including, but not limited to, DIN4102, BS476, ASTM E119, ULC-S101, etc. For industrial facilities in the hydrocarbon & petrochemical industries, a hydrocarbon curve (such as UL 1709) is used, reflecting a more rapid temperature rise. The only commonly used exposure beyond this, apart from the more recent tunnel curves shown above, would be the jet fire exposure standards such as ISO 22899, which are used where equipment may be subject to the extreme heat and momentum effects of jet fire exposure.
Big differences between different countries in terms of the use of the curves include the use of pipes, which shield the furnace thermocouples inside of NAFTA testing laboratories. This slows down the response time and results in a somewhat more conservative test regime in North America. On the other hand, the ISO based European curves run somewhat hotter for most of the test. North America also selectively uses a hose-stream test between 30 and 45PSI, to simulate real-world impacts and damages that may not be simulated in a laboratory. The US Navy even insists on a 90PSI hose-stream test for some of its assemblies, which may simulate the pressure available to firefighters in fighting a fire, but which has little to do with countermeasures against damaging effects of manual fire suppression. The hose-stream is simply intended to add a level of toughness to matters because without this, some fairly flimsy systems can pass a test, thus receive a rating and thus be permissible by a building code but be so weak that ordinary building use may damage a thus qualified system before it encounters a fire.
Germany's DIN4102 also includes a significant impact test for a potential firewall, which is, however, applied from the wrong side: the cold side. Applying the impact from the cold side is more practical to do in a lab setting, however, potential impacts should come from the exposed side, not the unexposed side. Still, for the person designing, building and paying for the test, the fire resistance itself may be rather uneventful unless major problems appear. The burn itself is the long duration, up to 4 hours, but the hose stream test only lasts a few minutes, with large damage potential due to the sudden thermal and kinetic impacts, as the fire was upwards of 1,100 C (see curves above), whereas the sudden hose-stream test is as cold as the domestic water fed to the fire hose used in the test, which might be 10-20 C. This combined impact explains the debris that can be seen coming from test specimens during the hose stream test, as seen herein.
Because of the large differences in test regimes all over the world, even for identical products and systems, organizations that intend to market their products internationally are often required to run many tests in many countries. Even where test regimes are identical, countries are often reluctant to accept the test results and particularly the certification methods of other countries.
During a fire in a tunnel, as well as in the petrochemical industry, temperatures exceed those of ordinary building (cellulosic) fires. This is because the fuel for the fire is hydrocarbons, which burn hotter (compare hydrocarbon curve above to ASTM E119 curve), faster and typically run out of fuel faster as well, compared against timber. The added complication with tunnels is that the environment inside a "tube" is best described as a "microclimate". The heat cannot escape as well as it can in a burning refinery, which is in the open. Instead, the fire is confined to a narrow tube, where pressure and heat build up and spread rapidly, with little room for escape and little chance of compartmentalization. This scenario was tested and quantified, particularly during the "Eureka Project", run by Technische Universitt Braunschweig's iBMB, Ekkehard Richter. The Netherlands, through Rijkswaterstaat in particular, mandated an extremely tough standard, the curve of which is shown in the gallery above.
Example of a fire stop fire-resistance rating test[edit]
Construction of a test sample consists of a mockup of a section of concrete floor, with typical mechanical and electrical utility components (pipes and cables) penetrating the floor assembly. A firestop mortar is applied around the penetrations.
The completed test sample is inserted into a furnace such that one side is exposed to a fire. The test is terminated when the fire stops successfully meet the test criteria in minimizing the amount of heat and smoke allowed to pass through the assembly, when the fire penetrates the fire stops. This determines the fire stop F-Rating. The length of time required for a penetrant or sample on average to exceed a specified average heat rise above ambient at any single location determines the duration for the FT Rating (Fire and Temperature). If a hose-stream test is passed afterwards, the rating can then be expressed as an FTH Rating (Fire, Temperature and Hose-stream). The lowest of the three determines the overall rating.
Part B: The Burning Branding Test. This test consists of mock decks being subject the placement of a burning brand in the center of the mock deck to simulate the falling of burning embers during a wildfire. The deck must be absent of flame after the 40 minute test period and lack structural failure of any boards.
Fire Retardant Glass - UL9 Certified Fire Resistant glass in USA - 284 F for 180 minutes
Floor area - Amount of area taken up by a building or part of it
Amount of area taken up by a building or part of it
In architecture, construction, and real estate, floor area, floor space, or floorspace is the area (measured as square feet or square metres) taken up by a building or part of it. The ways of defining "floor area" depend on what factors of the building should or should not be included, such as external walls, internal walls, corridors, lift shafts, stairs, etc. Generally there are three major differences in measuring floor area.[1]
Gross floor area (GFA) - The total floor area contained within the building measured to the external face of the external walls.
Gross internal area (GIA) - The floor area contained within the building measured to the internal face of the external walls.
Net internal area (NIA) (or usable floor area UFA) - The NIA is the GIA less the floor areas taken up by lobbies, enclosed machinery rooms on the roof, stairs and escalators, mechanical and electrical services, lifts, columns, toilet areas (other than in domestic property), ducts, and risers.
Contents - Gross floor area (GFA) in real estate is the total floor area inside the building envelope, including the external walls, and excluding the roof.
Gross floor area (GFA) in real estate is the total floor area inside the building envelope, including the external walls, and excluding the roof.
Definitions of GFA, including which areas are to be counted towards it and which areas aren't, vary around the world. Adding to this confusion is the practice among some developers to use gross leasable area (GLA) and GFA interchangeably, or to use GFA as GLA, even though GLA usually excludes corridors and other public areas inside the development, while both figures include areas occupied by structure, like walls and columns.
Subject to sub-paragraph (b), for the purposes of regulations 19, 20, 21 and 22, the gross floor area of a building shall be the area contained within the external walls of the building measured at each floor level (including any floor below the level of the ground), together with the area of each balcony in the building, which shall be calculated from the overall dimensions of the balcony (including the thickness of the sides thereof), and the thickness of the external walls of the building.
sub-paragraph (b): - In determining the gross floor area for the purposes of regulations 20, 21 and 22, the Building Authority may disregard any floor space that he is satisfied is constructed or intended to be used solely for parking motor vehicles, loading or unloading of motor vehicles, or for refuse storage chambers, refuse storage and material recovery chambers, material recovery chambers, refuse storage and material recovery rooms, refuse chutes, refuse hopper rooms and other types of facilities provided to facilitate the separation of refuse to the satisfaction of the Building Authority, or for access facilities for telecommunications and broadcasting services, or occupied solely by machinery or equipment for any lift, air-conditioning or heating system or any similar service. (L.N. 406 of 1987; 39 of 2000 s. 7)
In determining the gross floor area for the purposes of regulations 20, 21 and 22, the Building Authority may disregard any floor space that he is satisfied is constructed or intended to be used solely for parking motor vehicles, loading or unloading of motor vehicles, or for refuse storage chambers, refuse storage and material recovery chambers, material recovery chambers, refuse storage and material recovery rooms, refuse chutes, refuse hopper rooms and other types of facilities provided to facilitate the separation of refuse to the satisfaction of the Building Authority, or for access facilities for telecommunications and broadcasting services, or occupied solely by machinery or equipment for any lift, air-conditioning or heating system or any similar service. (L.N. 406 of 1987; 39 of 2000 s. 7)
The non-accountable GFA is further defined in Practice Notes for Authorized Persons, Registered Structural Engineers and Registered Geotechnical Engineers no APP-2.[2]
Permitted GFA in Hong Kong land lease agreement generally the maximum GFA (excluding the non-accountable above) to develop. However it may be further reduced by the effect of plot ratio, maximum site coverage, maximum permitted height of building and Outline Zoning Plan. Moreover, roof and other uncovered area is exclude in Permitted GFA but usually had restricted use as opening space, corridor or emergence escaping area.
Green features - Since 2001, to encourage the incorporation of green features in building developments, further facilities could be excluded/disregard in GFA.[3] and defined at Joint Practice Notes on protection and improvement of the built and natural environment no. 1 and no. 2.[4][5] Since such facilities granted extra floor area to develop and usually included in the GFA/ selling area the developer sold to end-user, which made end-user confused, government planned to abolish the exclusion of green features and use alternative way to encourage green features. For the total floor area, HK use the term Site Coverage.
Since 2001, to encourage the incorporation of green features in building developments, further facilities could be excluded/disregard in GFA.[3] and defined at Joint Practice Notes on protection and improvement of the built and natural environment no. 1 and no. 2.[4][5] Since such facilities granted extra floor area to develop and usually included in the GFA/ selling area the developer sold to end-user, which made end-user confused, government planned to abolish the exclusion of green features and use alternative way to encourage green features. For the total floor area, HK use the term Site Coverage.
3.1 All covered floor areas of a building, except otherwise exempted, and uncovered areas for commercial uses are deemed the gross floor area of the building for purposes of plot ratio control and development charge. The gross floor area is the total area of the covered floor space measured between the centre line of party walls, including the thickness of external walls but excluding voids. Accessibility and usability are not criteria for exclusion from GFA.
3.2 URA reserves the right to decide on GFA matters based on the specific design of a development proposal on a case-by-case basis.
With effect from January 2014, Private enclosed spaces (PES) and private roof terraces (PRT) are counted as part of the bonus GFA capped at 10% above the Master Plan that also includes balconies.[7]
Gross leasable area (GLA) is the amount of floor space available to be rented in a commercial property. Specifically, gross leasable area is the total floor area designed for tenant occupancy and exclusive use, including any basements, mezzanines, or upper floors. It is typically expressed in square metres (although in some places such as the United States, Canada and the United Kingdom, the square foot is used). It is measured from the center line of joint partitions and from outside wall faces. That is, gross leasable area is the area for which tenants pay rent, and thus the area that produces income for the property owner.
For a property with only one tenant, the measurements Gross Floor Area (GFA) and Gross Leasable Area (GLA) are essentially equal.
^ Jim Smith and David Jaggar, Building Cost Planning for the Design Team, Butterworth-Heinemann, London, 2006. Duncan Cartlidge, Quantity Surveyor's Pocket Book, Butterworth-Heinemann, London, 2009.
^ "JPN1: Green and Innovative Buildings" (PDF). Buildings Department, Lands Department & Planning Department. Government of Hong Kong. Retrieved 2010-02-16.
In architecture and building engineering, a floor plan is a drawing to scale, showing a view from above, of the relationships between rooms, spaces, traffic patterns, and other physical features at one level of a structure.
Dimensions are usually drawn between the walls to specify room sizes and wall lengths. Floor plans may also include details of fixtures like sinks, water heaters, furnaces, etc. Floor plans may include notes for construction to specify finishes, construction methods, or symbols for electrical items.
It is also called a plan which is a measured plane typically projected at the floor height of 4 ft (1.2 m), as opposed to an elevation which is a measured plane projected from the side of a building, along its height, or a section or cross section where a building is cut along an axis to reveal the interior structure.
Contents - Similar to a map, the orientation of the view is downward from above, but unlike a conventional map, a plan is drawn at a particular vertical position (commonly at about four feet above the floor). Objects below this level are seen, objects at this level are shown 'cut' in plan-section, and objects above this vertical position within the structure are omitted or shown dashed. Plan view or planform is defined as a vertical orthographic projection of an object on a horizontal plane, like a map.
Similar to a map, the orientation of the view is downward from above, but unlike a conventional map, a plan is drawn at a particular vertical position (commonly at about four feet above the floor). Objects below this level are seen, objects at this level are shown 'cut' in plan-section, and objects above this vertical position within the structure are omitted or shown dashed. Plan view or planform is defined as a vertical orthographic projection of an object on a horizontal plane, like a map.
The term may be used in general to describe any drawing showing the physical layout of objects. For example, it may denote the arrangement of the displayed objects at an exhibition, or the arrangement of exhibitor booths at a convention. Drawings are now reproduced using plotters and large format xerographic copiers.
A reflected ceiling plan (RCP) shows a view of the room as if looking from above, through the ceiling, at a mirror installed one foot below the ceiling level, which shows the reflected image of the ceiling above. This convention maintains the same orientation of the floor and ceilings plans looking down from above. RCPs are used by designers and architects to demonstrate lighting, visible mechanical features, and ceiling forms as part of the documents provided for construction.
The art of constructing ground plans (ichnography; Gr. , chnos, "track, trace" and , grphein, "to write";[1] pronounced ik-nog-rfi) was first described by Vitruvius (i.2) and included the geometrical projection or horizontal section representing the plan of any building, taken at such a level as to show the outer walls, with the doorways, windows, fireplaces, etc., and the correct thickness of the walls; the position of piers, columns or pilasters, courtyards and other features which constitute the design,[2] as to scale.
Floor plans use standard symbols to indicate features such as doors. This symbol shows the location of the door in a wall and which way the door opens.
A floor plan is not a top view or birds eye view. It is a measured drawing to scale of the layout of a floor in a building. A top view or bird's eye view does not show an orthogonally projected plane cut at the typical four foot height above the floor level. A floor plan could show:[3]
interior walls and hallways - restrooms
restrooms - windows and doors
windows and doors - appliances such as stoves, refrigerators, water heater etc.
appliances such as stoves, refrigerators, water heater etc.
interior features such as fireplaces, saunas and whirlpools
A plan view is an orthographic projection of a three-dimensional object from the position of a horizontal plane through the object. In other words, a plan is a section viewed from the top. In such views, the portion of the object above the plane (section) is omitted to reveal what lies beyond. In the case of a floor plan, the roof and upper portion of the walls may typically be omitted. Whenever an interior design project is being approached, a floor plan is the typical starting point for any further design considerations and decisions.
Roof plans are orthographic projections, but they are not sections as their viewing plane is outside of the object.
A plan is a common method of depicting the internal arrangement of a three-dimensional object in two dimensions. It is often used in technical drawing and is traditionally crosshatched. The style of crosshatching indicates the type of material the section passes through.
A 3D floor plan can be defined as a virtual model of a building floor plan. It is often used to better convey architectural plans to individuals not familiar with floor plans. Despite the purpose of floor plans originally being to depict 3D layouts in a 2D manner, technological expansion has made rendering 3D models much more cost effective. 3D plans show a better depth of image and are often complemented by 3D furniture in the room. This allows a greater appreciation of scale than with traditional 2D floor plans.
^ One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Ichnography". Encyclopdia Britannica. 14 (11th ed.). Cambridge University Press. p. 243.
Glossary of Terms - A
A - Abrasion A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the lubricant. It may also cause a break down of the material (such as the tooth surfaces of gears). Lack of proper lubrication may result in abrasion.
Abrasion A general wearing away of a surface by constant scratching, usually due to the presence of foreign matter such as dirt, grit, or metallic particles in the lubricant. It may also cause a break down of the material (such as the tooth surfaces of gears). Lack of proper lubrication may result in abrasion.
Abrasive Wear (Or cutting wear) Comes about when hard surface asperities or hard particles that have embedded themselves into a soft surface and plough grooves into the opposing harder surface, e.g., a journal.
Absolute Filtration Rating The diameter of the largest hard spherical particle that will pass through a filter under specified test conditions. This is an indication of the largest opening in the filter elements.
Absolute Pressure The sum of atmospheric and gage pressure.
Absolute Viscosity A term used interchangeably with viscosity to distinguish it from either kinematic viscosity or commercial viscosity. Absolute viscosity is the ratio of shear stress to shear rate. It is a fluid's internal resistance to flow. The common unit of absolute viscosity is the poise. Absolute viscosity divided by fluid density equals kinematic viscosity. It is occasionally referred to as dynamic viscosity. Absolute viscosity and kinematic viscosity are expressed in fundamental units. Commercial viscosity such as Saybolt viscosity is expressed in arbitrary units of time, usually seconds.
Absorbent Filter A filter medium that holds contaminant by mechanical means.
Absorption The assimilation of one material into another; in petroleum refining, the use of an absorptive liquid to selectively remove components from a process stream.
AC Fine Test Dust (ACFTD) A test contaminant used to assess both filters and the contaminant sensitivity of all types of tribological mechanisms.
Accumulator A container in which fluid is stored under pressure as a source of fluid power.
Acid In a restricted sense, any substance containing hydrogen in combination with a nonmetal or nonmetallic radical and capable of producing hydrogen ions in solution.
Acid Number The quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize the acidic constituents in 1 g of sample.
Acid Sludge The residue left after treating petroleum oil with sulfuric acid for the removal of impurities. It is a black, viscous substance containing the spent acid and impurities.
Acid Treating A refining process in which unfinished petroleum products, such as gasoline, kerosene, and lubricating oil stocks, are contacted with sulfuric acid to improve their color, odor, and other properties
Acidity In lubricants, acidity denotes the presence of acid-type constituents whose concentration is usually defined in terms of total acid number. The constituents vary in nature and may or may not markedly influence the behavior of the lubricant.
Activated Alumina A highly porous material produced from dehydroxylated aluminium hydroxide. Is used as a desiccant and as a filtering medium.
Actuator A device used to convert fluid energy into mechanical motion.
Additive A chemical substance added to a petroleum product to impart or improve certain properties. Common petroleum product additives are: antifoam agent, anti-wear additive, corrosion inhibitor, demulsifier, detergent, dispersant, emulsifier, EP additive, oiliness agent, oxidation inhibitor, pour point depressant, rust inhibitor, tackiness agent, viscosity index (VI.) improver.
Additive Level The total percentage of all additives in an oil. (Expressed in % of mass (weight) or % of volume)
Additive stability The ability of additives in the fluid to resist changes in their performance during storage or use.
Adhesion The property of a lubricant that causes it to cling or adhere to a solid surface.
Adhesive Wear Is often referred to as galling, scuffing, scoring, or seizing. It happens when sliding surfaces contact one another, causing fragments to be pulled from one surface and to adhere to the other.
Adsorbent Filter A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion.
Adsorption Adhesion of the molecules of gases, liquids, or dissolved substances to a solid surface, resulting in relatively high concentration of the molecules at the place of contact; e.g. the plating out of an anti-wear additive on metal surfaces.
Adsorptive Filtration The attraction to, and retention of particles in, a filter medium by electrostatic forces, or by molecular attraction between the particles and the medium.
Aeration The state of air being suspended in a liquid such as a lubricant or hydraulic fluid.
Agglomeration The potential of the system for particle attraction and adhesion.
AGMA An acronym for "American Gear Manufacturers Associations," an organization serving the gear industry.
AGMA Lubricant Numbers AGMA specification covering gear lubricants. The viscosity ranges of the AGMA numbers (or grades) conform to the International Standards Organization (ISO) viscosity classification system (see ISO viscosity classification system).
Air Bleeder A device for removal of air from a hydraulic fluid line.
Air Breather A device permitting air movement between atmosphere and the component in/on which it is installed.
Air Entrainment The incorporation of air in the form of bubbles as a dispersed phase in the bulk liquid. Air may be entrained in a liquid through mechanical means and/or by release of dissolved air due to a sudden change in environment. The presence of entrained air is usually readily apparent from the appearance of the liquid (i.e., bubbly, opaque, etc.) while dissolved air can only be determined by analysts.
Air Motor A device which converts compressed gas into mechanical force and motion. It usually provides rotary mechanical motion.
Air/Oil Systems A lubrication system in which small measured quantities of oil are introduced into an air/oil mixing device which is connected to a lube line that terminates at a bearing, or other lubrication point. The air velocity transports the oil along the interior walls of the lube line to the point of application. These systems provide positive air pressure within the bearing housing to prevent the ingress of contaminants, provide cooling air flow to the bearing, and perform the lubrication function with a continuous flow of minute amounts of oil.
Air-Gap Solenoid A solenoid that is sealed to prevent leakage of the liquid indo the plunger cavity
Alkali Any substance having basic (as opposed to acidic) properties. In a restricted sense it is applied to the hydroxides of ammonium, lithium, potassium and sodium. Alkaline materials in lubricating oils neutralize acids to prevent acidic and corrosive wear in internal combustion engines.
Almen EP Lubricant Tester A journal bearing machine used for determining the load-carrying capacity or Extreme Pressure properties (EP) of gear lubricants.
Aluminum Alloy White particles which indicate wear of aluminum component such as a casing wall.
Ambient Temperature Temperature of the area or atmosphere around a process, (not the operating temperature of the process itself).
Amp Ampere - Analytical Ferrography The magnetic precipitation and subsequent analysis of wear debris from a fluid sample This approach involves passing a volume of fluid over a chemically treated microscope slide which is supported over a magnetic field. Permanent magnets are arranged in such a way as to create a varying field strength over the length of the substrate. This varying strength causes wear debris to precipitate in a distribution with respect to size and mass over the Ferrogram. Once rinsed and fixed to the substrate, this debris deposit serves as an excellent media for optical analysis of the composite wear particulates.
Analytical Ferrography The magnetic precipitation and subsequent analysis of wear debris from a fluid sample This approach involves passing a volume of fluid over a chemically treated microscope slide which is supported over a magnetic field. Permanent magnets are arranged in such a way as to create a varying field strength over the length of the substrate. This varying strength causes wear debris to precipitate in a distribution with respect to size and mass over the Ferrogram. Once rinsed and fixed to the substrate, this debris deposit serves as an excellent media for optical analysis of the composite wear particulates.
Anhydrous Devoid of water. - Aniline Point The minimum temperature for complete miscibility of equal volumes of aniline and the sample under test ASTM Method D611. A product of high aniline point will be low in aromatics and naphthenes and, therefore, high in paraffins. Aniline point is often specified for spray oils, cleaning solvents, and thinners, where effectiveness depends upon aromatic content. In conjunction with API gravity, the aniline point may be used to calculate the net heat of combustion for aviation fuels.
Aniline Point The minimum temperature for complete miscibility of equal volumes of aniline and the sample under test ASTM Method D611. A product of high aniline point will be low in aromatics and naphthenes and, therefore, high in paraffins. Aniline point is often specified for spray oils, cleaning solvents, and thinners, where effectiveness depends upon aromatic content. In conjunction with API gravity, the aniline point may be used to calculate the net heat of combustion for aviation fuels.
ANSI American National Standards Institute - Anti-foam Agent One of two types of additives used to reduce foaming in petroleum products: silicone oil to break up large surface bubbles, and various kinds of polymers that decrease the amount of small bubbles entrained in the oils.
Anti-foam Agent One of two types of additives used to reduce foaming in petroleum products: silicone oil to break up large surface bubbles, and various kinds of polymers that decrease the amount of small bubbles entrained in the oils.
Anti-friction Bearing A rolling contact type bearing in which the rotating or moving member is supported or guided by means of ball or roller elements. Does not mean without friction.
Anti-oxidants Prolong the induction period of a base oil in the presence of oxidizing conditions and catalyst metals at elevated temperatures. The additive is consumed and degradation products increase not only with increasing and sustained temperature, but also with increases in mechanical agitation or turbulence and contamination
Antistatic Additive An additive that increases the conductivity of a hydrocarbon fuel to hasten the dissipation of electrostatic charges during high-speed dispensing, thereby reducing the fire/explosion hazard.
Antiwear Additives Improve the service life of tribological elements operating in the boundary lubrication regime. Antiwear compounds (for example, ZDDP and TCP) start decomposing at 90 degrees to 100 degrees C and even at a lower temperature if water (25 to 50 ppm) is present.
API An acronym for American Petroleum Institute. A trade association of petroleum producers, refiners, marketers, and transporters, organized for the advancement of the petroleum industry by conducting research, gathering and disseminating information, and maintaining cooperation between government and the industry on all matters of mutual interest.
API Engine Service Categories Gasoline and diesel engine oil quality levels established jointly by API, SAE, and ASTM, and sometimes called SAE or API/SAE categories; formerly called API Engine Service Classifications.
API Gravity A gravity scale established by the American Petroleum Institute and in general use in the petroleum industry, the unit being called "the A.P.I. degree." This unit is defined in terms of specific gravity as follows:
Apparent Viscosity The ratio of shear stress to rate of shear of a non-Newtonian fluid such as lubricating grease, or a multi-grade oil, calculated from Poiseuilles equation and measured in poises. The apparent viscosity changes with changing rates of shear and temperature and must, therefore, be reported as the value at a given shear rate and temperature (ASTM Method D 1092).
Aqueous Decontamination Removal of a chemical or biological hazard with a water-base solution
Aromatic Derived From, or characterized by, the presence of the benzene ring.
ARP An acronym for Aeronautical Recommended Practice - Ash A measure of the amount of inorganic material in lubricating oil. Determined by burning the oil and weighing the residue. Results expressed as percent by weight.
Ash A measure of the amount of inorganic material in lubricating oil. Determined by burning the oil and weighing the residue. Results expressed as percent by weight.
ASLE American Society of Lubrication Engineers. Changed now to Society of Tribologist and Lubrication Engineers (STLE).
ASME American Society of Mechanical Engineers - Asperities Microscopic projections on metal surfaces resulting from normal surface-finishing processes. Interference between opposing asperities in sliding or rolling applications is a source of friction, and can lead to metal welding and scoring. Ideally, the lubricating film between two moving surfaces should be thicker than the combined height of the opposing asperities.
Asperities Microscopic projections on metal surfaces resulting from normal surface-finishing processes. Interference between opposing asperities in sliding or rolling applications is a source of friction, and can lead to metal welding and scoring. Ideally, the lubricating film between two moving surfaces should be thicker than the combined height of the opposing asperities.
ASTM Acronym for "American Society for Testing Materials." A society for developing standards for materials and test methods.
ASTM D2670 Pin and V-Block Test ASTM Test Method D2670 is for measuring the antiwear properties of liquid lubricants. The load is applied to the jaws and maintained by a toothed wheel. The wear is a function of the number of the tooth which needs to be engaged to keep the load constant for a fixed time.
ASTM D5302 Sequence VE ASTM Test Method D 5302, the Sequence VE gasoline engine test, has been correlated with vehicles used in stop-and-go service prior to 1988, particularly with regard to sludge and valve train wear.
ASTM D5533 Sequence IIIF ASTM Test Method D 5533, the Sequence IIIE gasoline engine test, has been correlated with vehicles used in high-temperature service prior to 1988, particularly with regard to oil thickening and valve train wear.
Atmospheric Pressure Pressure exerted by the atmosphere at any specific location. (Sea level pressure is approximately 14.7 pounds per square inch absolute.)
Atomic Absorption Spectroscopy Measures the radiation absorbed by chemically unbound atoms by analyzing the transmitted energy relative to the incident energy at each frequency. The procedure consists of diluting the fluid sample with methyl isobutyl ketone (MIBK) and directly aspirating the solution. The actual process of atomization involves reducing the solution to a fine spray, dissolving it, and finally vaporizing it with a flame. The vaporization of the metal particles depends upon their time in the flame, the flame temperature, and the composition of the flame gas. The spectrum occurs because atoms in the vapor state can absorb radiation at certain well-defined characteristic wave lengths. The wave length bands absorbed are very narrow and differ for each element. In addition, the absorption of radiant energy by electronic transitions from ground to excited state is essentially and absolute measure of the number of atoms in the flame and is, therefore, the concentration of the element in a sample.
Atomization The conversion of a liquid into a spray of very fine droplets.
Automatic Transmission Fluid (ATF) Fluid for automatic, hydraulic transmissions in motor vehicles.
Axial-load Bearing A bearing in which the load acts in the direction of the axis of rotation.
B - Babbitt A soft, white, non-ferrous alloy bearing material composed principally of copper, antimony, tin and lead.
Babbitt A soft, white, non-ferrous alloy bearing material composed principally of copper, antimony, tin and lead.
Back Pressure The pressure encountered on the return side of a system.
Background Contamination The total of the extraneous particles which are introduced in the process of obtaining, storing, moving, transferring and analyzing a fluid sample.
Bacteria Microorganisms often composed of a single cell.
Bactericide Additive included in the formulations of water-mixed cutting fluids to inhibit the growth of bacteria promoted by the presence of water, thus preventing odors that can result from bacterial action.
Baffle A device to prevent direct fluid flow or impingement on a surface.
Ball Bearing An antifriction rolling type bearing containing rolling elements in the form of balls.
Barrel A unit of liquid volume of petroleum oils equal to 42 U.S. gallons or approximately 35 Imperial gallons.
Base A material which neutralizes acids. An oil additive containing colloidally dispersed metal carbonate, used to reduce corrosive wear.
Base Number The amount of acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide, required to neutralize all basic constituents present in 1 g of sample
Base Oil A base oil is a base stock or blend of base stocks used in an API-licensed engine oil.
Base Stock The base fluid, usually a refined petroleum fraction or a selected synthetic material, into which additives are blended to produce finished lubricants.
Batch Any quantity of material handled or considered as a "unit" in processing. i.e., any sample taken from the same batch will have the same properties and/or qualities.
Bearing A support or guide by means of which a moving part such as a shaft or axle is positioned with respect to the other parts of a mechanism.
Bellows Seal A type of mechanical seal which utilizes bellows for providing secondary sealing and spring-type loading.
Bernouillis Theory If no work is done on or by a flowing, frictionless liquid, its energy, due to pressure and velocity, remains constant at all points along the streamline.
Beta Rating The method of comparing filter performance based on efficiency. This is done using the Multi-Pass Test which counts the number of particles of a given size before and after fluid passes through a filter.
Beta-Ratio The ratio of the number of particles greater than a given size in the influent fluid to the number of particles greater than the same size in the effluent fluid, under specified test conditions (see "Multi-Pass Test").
Bevel Gear A straight-toothed gear with the teeth cut on sloping faces and the gear shafts at an angle (normally a right angle)
Biocides Additive designed to inhibit the growth of microorganisms in liquids
Biodegradation The chemical breakdown of materials by living organisms in the environment. The process depends on certain microorganisms, such as bacteria, yeast, and fungi, which break down molecules for sustenance. Certain chemical structures are more susceptible to microbial breakdown than others; vegetable oils, for example, will biodegrade more rapidly than petroleum oils. Most petroleum products typically will completely biodegrade in the environment within two months to two years.
Bitumen Also called asphalt or tar, bitumen is the brown or black viscous residue from the vacuum distillation of crude petroleum. It also occurs in nature as asphalt "lakes" and "tar sands." It consists of high molecular weight hydrocarbons and minor amounts of sulfur and nitrogen compounds.
Black oils Lubricants containing asphaltic materials, which impart extra adhesiveness, that are used for open gears and steel cables.
Bleeding The separation of some of the liquid phase from a grease
Blending The process of mixing lubricants or components for the purpose of obtaining the desired physical and/or chemical properties (see compounding)
Blow-by Passage of unburned fuel and combustion gases past the piston rings of internal combustion engines, resulting in fuel dilution and contamination of the crankcase oil.
Boiling Point The temperature at which a substance boils, or is converted into vapor by bubbles forming within the liquid; it varies with pressure
Boiling Range For a mixture of substances, such as a petroleum fraction, the temperature interval between the initial and final boiling points.
Bomb Oxidation A test for the oxidation stability of a product obtained by sealing it in a closed container with oxygen under pressure. The drop in pressure of the oxygen is a measure of the amount of oxidation that has occurred.
Boundary Lubrication Form of lubrication between two rubbing surfaces without development of a full-fluid lubricating film. Boundary lubrication can be made more effective by including additives in the lubricating oil that provide a stronger oil film, thus preventing excessive friction and possible scoring. There are varying degrees of boundary lubrication, depending on the severity of service. For mild conditions, oiliness agents may be used; by plating out on metal surfaces in a thin but durable film, oiliness agents prevent scoring under some conditions that are too severe for a straight mineral oil. Compounded oils, which are formulated with polar fatty oils, are sometimes used for this purpose. Anti-wear additives are commonly used in more severe boundary lubrication applications. The more severe cases of boundary lubrication are defined as extreme pressure conditions; they are met with lubricants containing EP additives that prevent sliding surfaces from fusing together at high local temperatures and pressures.
Boyles Law The absolute pressure of a fixed mass of gas varies inversely as the volume, provided the temperature remains constant.
Breakdown Maintenance Maintenance performed after a machine has failed to return it to an operating state.
Bridging A condition of filter element loading in which contaminant spans the space between adjacent sections of a filter element, thus blocking a portion of the useful filtration.
Bright Stock A heavy residual lubricant stock with low pour point, used in finished blends to provide good bearing film strength, prevent scuffing, and reduce oil consumption. Usually identified by its viscosity, SUS at 210 degrees F or cSt at 100 degrees C.
Brinelling Permanent deformation of the bearing surfaces where the rollers (or balls) contact the races. Brinelling results from excessive load or impact on stationary bearings. It is a form of mechanical damage in which metal is displaced or upset without attrition.
Brookfield Viscosity Apparent viscosity in cP determined by Brookfield viscometer, which measures the torque required to rotate a spindle at constant speed in oil of a given temperature. Basis for ASTM Method D 2983; used for measuring low temperature viscosity of lubricants.
BTU British thermal unit. The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit.
Bubble Point The differential gas pressure at which the first steady stream of gas bubbles is emitted from a wetted filter element under specified test conditions.
Built-in-dirt Material passed into the effluent stream composed of foreign materials incorporated into the filter medium.
Bulk Modulus (of elasticity) A ratio of normal stress to a change in volume. A term used in determining the compressibility of a fluid. Data for petroleum products can be found in the International Critical Tables.
Burst pressure Rating The maximum specified inside-out differential pressure that can be applied to a filter element without outward structural or filter-medium failure.
Bushing A short, externally threaded connector with a smaller size internal thread.
Bypass Filtration A system of filtration in which only a portion of the total flow of a circulating fluid system passes through a filter at any instant or in which a filter having its own circulating pump operates in parallel to the main flow.
Bypass Valve (Relief valve) A valve mechanism that assures system fluid flow when a preselected differential pressure across the filter element is exceeded; the valve allows all or part of the flow to bypass the filter element.
C - C or cent. Centigrade
C or cent. Centigrade - CAF Corporate Average Fuel Economy
CAF Corporate Average Fuel Economy - Cams Eccentric shafts used in most internal combustion engines to open and close valves.
Cams Eccentric shafts used in most internal combustion engines to open and close valves.
Capacity The amount of contaminants a filter will hold before an excessive pressure drop is caused. Most filters have bypass valves which open when a filter reaches its rated capacity.
Capillarity A property of a solid-liquid system manifested by the tendency of the liquid in contact with the solid to rise above or fall below the level of the surrounding liquid; this phenomenon is seen in a smallbore (capillary) tube.
Capillary Viscometer A viscometer in which the oil flows through a capillary tube.
Carbon A non-metallic element - No. 6 in the periodic table. Diamonds and graphite are pure forms of carbon. Carbon is a constituent of all organic compounds. It also occurs in combined form in many inorganic substances; i.e., carbon dioxide, limestone, etc.
Carbon (deposit) Solid black residue in piston grooves which can interfere with piston ring movement leading to wear and/or loss of power.
Carbon Residue Coked material remaining after an oil has been exposed to high temperatures under controlled conditions.
Carbon Type The distinction between paraffinic, naphthenic, and aromatic molecules. In relation to lubricant base stocks, the predominant type present.
Carbonyl Iron Powder A contaminant which consists of up to 99.5% pure iron spheres.
Carcinogen A cancer-causing substance. Certain petroleum products are classified as potential carcinogens OSHA criteria. Suppliers are required to identify such products as potential carcinogens on package labels and Material Safety Data Sheets.
Cartridge Seal A completely self-contained assembly including seal, gland, sleeve, mating ring, etc., usually needing no installation measurement.
Case Drain Filter A filter located in a line conducting fluid from a pump or motor housing to reservoir.
Case Drain Line A line conducting fluid from a component housing to the reservoir.
Catalyst A substance that initiates or increases the rate of a chemical reaction, without itself being used up in the process.
Catalytic Converter An integral part of vehicle emission control systems since 1975. Oxidizing converters remove hydrocarbons and carbon monoxide (CO) from exhaust gases, while reducing converters control nitrogen oxide (NOx) emissions. Both use noble metal (platinum, palladium or rhodium) catalysts that can be "poisoned" by lead compounds in the fuel or lubricant.
Catastrophic Failure Sudden, unexpected failure of a machine resulting in considerable cost and downtime.
Caustic A highly alkaline substance such as sodium hydroxide.
Cavitation Formation of an air or vapor pocket (or bubble) due to lowering of pressure in a liquid, often as a result of a solid body, such as a propeller or piston, moving through the liquid; also, the pitting or wearing away of a solid surface as a result of the violent collapse of a vapor bubble. Cavitation can occur in a hydraulic system as a result of low fluid levels that draw air into the fluid, producing tiny bubbles that expand followed by rapid implosion, causing metal erosion and eventual pump destruction.
Cavitation Erosion A material-damaging process which occurs as a result of vaporous cavitation. "Cavitation" refers to the occurrence or formation of gas- or vapor- filled pockets in flowing liquids due to the hydrodynamic generation of low pressure (below atmospheric pressure). This damage results from the hammering action when cavitation bubbles implode in the flow stream. Ultra-high pressures caused by the collapse of the vapor bubbles produce deformation, material failure and, finally, erosion of the surfaces.
Cellulose Media A filter material made from plant fibers. Because cellulose is a natural material, its fibers are rough in texture and vary in size and shape. Compared to synthetic media, these characteristics create a higher restriction to the flow of fluids.
Centi Hundredth - Centipoise (cp) A unit of absolute viscosity. 1 centipoise = 0.01 poise.
Centipoise (cp) A unit of absolute viscosity. 1 centipoise = 0.01 poise.
Centistoke (cst) A unit of kinematic viscosity. 1 centistoke = 0.01 stoke.
Centralized Lubrication A system of lubrication in which a metered amount of lubricant or lubricants for the bearing surfaces of a machine or group of machines are supplied from a central location.
Centrifugal Separator A separator that removes immiscible fluid and solid contaminants that have a different specific gravity than the fluid being purified by accelerating the fluid mechanically in a circular path and using the radial acceleration component to isolate these contaminants.
Channeling The phenomenon observed among gear lubricants and greases when they thicken due to cold weather or other causes, to such an extent that a groove is formed through which the part to be lubricated moves without actually coming in full contact with the lubricant. A term used in percolation filtration; may be defined as: a preponderance of flow through certain portions of the clay bed.
Chemical Stability The tendency of a substance or mixture to resist chemical change.
Chip Control (grit control, last-chance) filter A filter intended to prevent only large particles from entering a component immediately downstream.
Chlorinated Wax Certain solid hydrocarbons treated with chlorine gas to form straight-chain hydrocarbons with a relatively high chlorine component. Chlorinated waxes are used primarily as polyvinyl chloride plasticizers, extreme-pressure additives for lubricants, and formulation components for many cutting fluids
Chromatography An analytical technique whereby a complex substance is adsorbed on a solid or liquid substrate and progressively eluted by a flow of a substance (the eluant) in which the components of the substance under investigation are differentially soluble. The eluant can be a liquid or a gas. When the substrate is filter paper and the eluant a liquid, a chromatogram of colored bands can be developed by use of indicators. For gas chromatography, electronic detectors are normally used to indicate passage of the various components from the system.
Circulating Header System A lubrication system having isolated lube zones wherein the lube pump runs continuously and circulates oil through the header, a return filter and back to tank during the idle period. When lubrication is required, a normal open solenoid valve in the return loop is actuated, allowing pump pressure to build. The zone valves are then sequentially opened to provide lubricant to the individual zones. Oil dispensed to the friction points is not reused, therefore, the system is a terminating type.
Circulating Oil A lubrication system wherein the oil pump runs continuously and circulates oil to the friction points on a continuous basis. The oil is drained back to tank, filtered, cooled as required and reused.
Circulating System A lubricating system in which oil is recirculated from a central sump to the parts requiring lubrication and then returned to the sump.
Clay Filtration A refining process using fullers earth (activated clay), bauxite or other mineral to absorb minute solids from lubricating oil, as well as remove traces of water, acids, and polar compounds.
Clean 100 particles >10 micron per milliliter - in regards to an oil sample bottle cleanliness
Clean Room A facility or enclosure in which air content and other conditions (such as temperature, humidity, and pressure) are controlled and maintained at a specific level by special facilities and operating processes and by trained personnel.
Cleanable Filter A filter element which, when loaded, can be restored by a suitable process, to an acceptable percentage of its original dirt capacity.
Cleanliness Level A measure of relative freedom from contaminants.
Clearance Bearing A journal bearing in which the radius of the bearing surface is greater than the radius of the journal surface.
Cleveland Open Cup A flash point test in which the surface of the sample is completely open to the atmosphere, and which is therefore relatively insensitive to small traces of volatile contaminants.
Cloud Point The temperature at which waxy crystals in an oil or fuel form a cloudy appearance.
Coalescor A separator that divides a mixture or emulsion of two immiscible liquids using the interfacial tension between the two liquids and the difference in wetting of the two liquids on a particular porous medium.
Coefficient of Friction The number obtained by dividing the friction force resisting motion between two bodies by the normal force pressing the bodies together.
Cohesion That property of a substance that causes it to resist being pulled apart by mechanical means.
Coking The undesirable accumulation of carbon (coke) deposits in the internal combustion engine or in a refinery plant. The process of distilling a petroleum product to dryness
Cold Cranking Simulator An intermediate shear rate viscometer that predicts the ability of an oil to permit a satisfactory cranking speed to be developed in a cold engine.
Collapse An inward structural failure of a filter element which can occur due to abnormally high pressure drop (differential pressure) or resistance to flow.
Collapse Pressure The minimum differential pressure that an element is designed to withstand without permanent deformation.
Complex Grease A lubricating grease thickened by a complex soap consisting of a normal soap and a complexing agent.
Compound (1) chemically speaking, a distinct substance formed by the combination of two or more elements in definite proportions by weight and possessing physical and chemical properties different from those of the combining elements. (2) in petroleum processing, generally connotes fatty oils and similar materials foreign to petroleum added to lubricants to impart special properties.
Compounded Oil A petroleum oil to which has been added other chemical substances.
Compounding The addition of fatty oils and similar materials to lubricants to impart special properties. Lubricating oils to which such materials have been added are known as compounded oils.
Compressed Air Air at any pressure greater than atmospheric pressure.
Compressibility A compound that enhances some property of, or imparts some new property to, the base fluid. In some hydraulic fluid formulations, the additive volume may constitute as much as 20 percent of the final composition. The more important types of additives include anti-oxidants, anti-wear additives, corrosion inhibitors, viscosity index improvers, and foam suppressants.
Compression Ratio In an internal combustion engine, the ratio of the volume of combustion space at bottom dead center to that at top dead center.
Compressor A device which converts mechanical force and motion into pneumatic fluid power.
Consistency The degree to which a semisolid material such as grease resists deformation. (See ASTM designation D 217.) Sometimes used qualitatively to denote viscosity of liquids.
Contaminant Any foreign or unwanted substance that can have a negative effect on system operation, life or reliability.
Contaminant Capacity (Dirt, ACFTD) The weight of a specified artificial contaminant that must be added to the influent to produce a given differential pressure across a filter at specified conditions. Used as an indication of relative service life.
Contaminant Capacity The weight of a specified artificial contaminant which must be added to the influent to produce a given differential pressure across a filter at specified conditions. Used as an indication of relative service life.
Contaminant Failure Any loss of performance due to the presence of contamination. Two basic types of contamination failure are: Perceptible
Contaminant Lock A particle or fiber-induced jam caused by solid contaminants.
Contamination Control A broad subject which applies to all types of material systems (including both biological and engineering). It is concerned with planning, organizing, managing, and implementing all activities required to determine, achieve and maintain a specified contamination level.
Coolant A fluid used to remove heat. See Cutting fluid.
Copper Strip Corrosion The gradual eating away of copper surfaces as the result of oxidation or other chemical action. It is caused by acids or other corrosive agents.
Core The internal duct and filter media support.
Corrosion The decay and loss of a metal due to a chemical reaction between the metal and its environment. It is a transformation process in which the metal passes from its elemental form to a combined (or compound) form.
Corrosion Inhibitor Additive for protecting lubricated metal surfaces against chemical attack by water or other contaminants. There are several types of corrosion inhibitors. Polar compounds wet the metal surface preferentially, protecting it with a film of oil. Other compounds may absorb water by incorporating it in a water-in-oil emulsion so that only the oil touches the metal surface. Another type of corrosion inhibitor combines chemically with the metal to present a non-reactive surface.
Coupling A straight connector for fluid lines. - Cracking The process whereby large molecules are broken down by the application of heat and pressure to form smaller molecules.
Cracking The process whereby large molecules are broken down by the application of heat and pressure to form smaller molecules.
Cracking Pressure The pressure at which a pressure operated valve begins to pass fluid.
Crankcase Oil Lubricant used in the crankcase of the internal combustion engine.
Crown The top of the piston in an internal combustion engine above the fire ring, exposed to direct flame impingement.
Cryogenics The branch of physics relating to the production and effects of very low temperatures.
Cutting Fluid Any fluid applied to a cutting tool to assist in the cutting operation by cooling, lubricating or other means.
Cutting Oil A lubricant used in machining operations for lubricating the tool in contact with the workpiece, and to remove heat. The fluid can be petroleum based, water based, or an emulsion of the two. The term emulsifiable cutting oil normally indicates a petroleum-based concentrate to which water is added to form an emulsion which is the actual cutting fluid.
Cycle A single complete operation consisting of progressive phases starting and ending at the neutral position.
Cylinder A device which converts fluid power into linear mechanical force and motion. It usually consists of a moveable element such as a piston and piston rod, plunger rod, plunger or ram, operating with in a cylindrical bore.
Cylinder Oil A lubricant for independently lubricated cylinders, such as those of steam engines and air compressors; also for lubrication of valves and other elements in the cylinder area. Steam cylinder oils are available in a range of grades with high viscosities to compensate for the thinning effect of high temperatures; of these, the heavier grades are formulated for super-heated and high-pressure steam, and the less heavy grades for wet, saturated, or low-pressure steam. Some grades are compounded for service in excessive moisture; see compounded oil. Cylinder oils lubricate on a once-through basis.
D - Deaerator A separator that removes air from the system fluid through the application of bubble dynamics.
Deaerator A separator that removes air from the system fluid through the application of bubble dynamics.
Degas Removing air from a liquid, usually by ultrasonic and/or vacuum methods.
Degradation The progressive failure of a machine or lubricant.
Dehydrator A separator that removes water from the system fluid.
Delamination Wear A complex wear process where a machine surface is peeled away or otherwise removed by forces of another surface acting on it in a sliding motion.
Demulsibility The ability of a fluid that is insoluble in water to separate from water with which it may be mixed in the form of an emulsion.
Demulsifier An additive that promotes oil-water separation in lubricants that are exposed to water or steam
Density The mass of a unit volume of a substance. Its numerical value varies with the units used.
Deplete The depletion of additives expressed as an approximate percentage.
Deposits Oil-insoluble materials that result from oxidation and decomposition of lube oil and contamination from external sources and engine blow-by. These can settle out on machine or engine parts. Examples are sludge, varnish, lacquer and carbon.
Depth Filter A filter medium that retains contaminants primarily within tortuous passages.
Depth Filter Media Porous materials which primarily retain contaminants within a tortuous path, performing the actual process of filtration.
Dermatitis Inflammation of the skin. Repeated contact with petroleum products can be a cause.
Desorption Opposite of absorption or adsorption. In filtration, it relates to the downstream release of particles previously retained by the filter.
Detergent In lubrication, either an additive or a compounded lubricant having the property of keeping insoluble matter in suspension thus preventing its deposition where it would be harmful. A detergent may also redisperse deposits already formed.
Detergent Oil Is a lubricating oil possessing special sludge-dispersing properties usually conferred on the oil by the incorporation of special additives. Detergent oils hold formed sludge particles in suspension and thus promote cleanliness especially in internal-combustion engines. However detergent oils do not contain detergents such as those used for cleaning of laundry or dishes. Also detergent oils do not clean already dirty engines, but rather keep in suspension the sludge that petroleum oil forms so that the engine remains cleaner for longer period. The formed sludge particles are either filtered out by Oil Filters or drained out when oil is changed.
Dewaxing Removal of wax from a base oil in order to reduce the pour point.
Dielectric Strength A measure of the ability of an insulating material to withstand electric stress (voltage) without failure. Fluids with high dielectric strength (usually expressed in volts or kilovolts) are good electrical insulators. (ASTM Designation D 877.)
Differential Pressure Indicator An indicator which signals the difference in pressure between two points, typically between the upstream and downstream sides of a filter element.
Differential Pressure Valve A valve whose primary function is to limit differential pressure.
Directional Control Servo Valve A directional control valve which modulates flow or pressure as a function of its input signal.
Directional Control Valve A valve whose primary function is to direct or prevent flow through selected passages.
Dirt Capacity The weight of a specified artificial contaminant which must be added to the influent to produce a given differential pressure across a filter at specified conditions. Used as an indication of relative service life.
Dispersant In lubrication, a term usually used interchangeably with detergent. An additive, usually nonmetallic ("ashless"), which keeps fine particles of insoluble materials in a homogeneous solution. Hence, particles are not permitted to settle out and accumulate.
Disposable A filter element intended to be discarded and replaced after one service cycle.
Dissolved Air Air which is dispersed in a fluid to form a mixture.
Dissolved Gases Those gases that enter into solution with a fluid and are neither free nor entrained gases.
Dissolved Water Water which is dispersed in the fluid to form a mixture.
Distillation Method (ASTM D-95) A method involving distilling the fluid sample in the presence of a solvent that is miscible in the sample but immiscible in water. The water distilled from the fluid is condensed and segregated in a specially-designed receiving tube or tray graduated to directly indicate the volume of water distilled.
Double Seal Two mechanical seals designed to permit a liquid or gas barrier fluid between the seals mounted back-to-back or face-to-face.
Drag The resistance to movement caused by oil viscosity.
Dropping Point In general, the dropping point is the temperature at which the grease passes from a semisolid to a liquid state. This change in state is typical of greases containing conventional soap thickeners. Greases containing thickeners other than conventional soaps may, without change in state, separate oil.
Drum A container with a capacity of 55 U.S. gallons.
Dry Lubrication The situation when moving surfaces have no liquid lubricant between them.
Dry Sump An engine design in which oil is not retained in a pan beneath the crankshaft thus permitting splash lubrication. There may be a remote sump from which oil is recirculated, or there may be a total loss system.
Dual-Line System A positive displacement terminating (oil, or grease) lubrication system that employs two main lines supplied from a pump connected to a 4-way (reverser) valve. Pressure in one main line (while the other is open to tank) causes the measuring piston(s) in the dual-line valve(s) to stroke in one direction dispensing lubricant to one group of lube points. Switching the 4-way (reverser) valve directs pump flow to the second main line and opens the first main line to tank. This allows pressure to build in the second main line causing the dual-line valve(s) measuring piston(s) to stroke back to their original position dispensing lubricant to a second group of lube points. The system is a parallel type and each dual-line valves operates independently of any other in the system.
Duplex Filter An assembly of two filters with valving for selection of either or both filters.
Dust Capacity The weight of a specified artificial contaminant which must be added to the influent to produce a given differential pressure across a filter at specified conditions. Used as an indication of relative service life.
Dynamic Seal A seal that moves due to axial or radial movement of the unit.
E - Effluent The fluid leaving a component.
Effluent The fluid leaving a component. - Elastohydrodynamic Lubrication In rolling element bearings, the elastic deformation of the bearing (flattening) as it rolls, under load, in the bearing race. This momentary flattening improves the hydrodynamic lubrication properties by converting point or line contact to surface-to-surface contact.
Elastohydrodynamic Lubrication In rolling element bearings, the elastic deformation of the bearing (flattening) as it rolls, under load, in the bearing race. This momentary flattening improves the hydrodynamic lubrication properties by converting point or line contact to surface-to-surface contact.
Elastomer A rubber or rubber-like material, both natural and synthetic, used in making a wide variety of products, such as seals and hoses. In oil seals, an elastomers chemical composition is a factor in determining its compatibility with a lubricant.
Electrical Insulating Oil A high-quality oxidation-resistant oil refined to give long service as a dielectric and coolant for electrical equipment, most commonly transformers. An insulating oil must resist the effects of elevated temperatures, electrical stress, and contact with air, which can lead to sludge formation and loss of insulation properties. It must be kept dry, as water is detrimental to dielectric strength the minimum voltage required to produce an electric arc through an oil sample, as measured by test method ASTM D 877.
Electrostatic Separator A separator that removes contaminant from dielectric fluids by applying an electrical charge to the contaminant that is then attracted to a collection device of different electrical charge.
Emission Spectrometer Works on the basis that atoms of metallic and other particular elements emit light at characteristic wavelengths when they are excited in a flame, arc, or spark. Excited light is directed through an entrance slit in the spectrometer. This light penetrates the slit, falls on a grate, and is dispersed and reflected. The spectrometer is calibrated by a series of standard samples containing known amounts of the elements of interest. By exciting these standard samples, an analytical curve can be established which gives the relationship between the light intensity and its concentration in the fluid.
Emulsibility The ability of a non-water-soluble fluid to form an emulsion with water.
Emulsifier Additive that promotes the formation of a stable mixture, or emulsion, of oil and water. Common emulsifiers are: metallic soaps, certain animal and vegetable oils, and various polar compounds.
Emulsion Intimate mixture of oil and water, generally of a milky or cloudy appearance. Emulsions may be of two types: oil-in water (where water is the continuous phase) and water-in-oil (where water is the discontinuous phase).
End Cap A ported or closed cover for the end of a filter element.
Engine Deposits Hard or persistent accumulation of sludge, varnish and carbonaceous residues due to blow-by of unburned and partially burned fuel, or the partial breakdown of the crankcase lubricant. Water from the condensation of combustion products, carbon, residues from fuel or lubricating oil additives, dust and metal particles also contribute.
Entrained Air A mechanical mixture of air bubbles having a tendency to separate from the liquid phase.
Environmental Contaminant All material and energy present in and around an operating system, such as dust, air moisture, chemicals, and thermal energy.
EP (Extreme Pressure) Lubricants Lubricants that impart to rubbing surfaces the ability to carry appreciably greater loads than would be possible with ordinary lubricants without excessive wear or damage.
Erosion The progressive removal of a machine surface by cavitation or by particle impingement at high velocities.
Externally Pressurized Seal A seal that has pressure acting on the seal parts from an external independent source of supply.
Extreme Pressure (EP) Additive Lubricant additive that prevents sliding metal surfaces from seizing under conditions of extreme pressure. At the high local temperatures associated with metal-to-metal contact, an EP additive combines chemically with the metal to form a surface film that prevents the welding of opposing asperities, and the consequent scoring that is destructive to sliding surfaces under high loads. Reactive compounds of sulfur, chlorine, or phosphorus are used to form these inorganic films.
F - Fabrication Integrity Point The differential gas pressure at which the first stream of gas bubbles are emitted from a wetted filter element under standard test conditions.
Fabrication Integrity Point The differential gas pressure at which the first stream of gas bubbles are emitted from a wetted filter element under standard test conditions.
Face Seal A device that prevents leakage of fluids along rotating shafts. Sealing is accomplished by a stationary primary seal ring bearing against the face of a mating ring mounted on a shaft. Axial pressure maintains the contact between the seal ring and the mating ring.
False Brinelling False brinelling of needle roller bearings is actually a fretting corrosion of the surface since the rollers are the I.D. of the bearing. Although its appearance is similar to that of brinelling, false brinelling is characterized by attrition of the steel, and the load on the bearing is less than that required to produce the resulting impression. It is the result of a combination of mechanical and chemical action that is not completely understood, and occurs when a small relative motion or vibration is accompanied by some loading, in the presence of oxygen.
Fat An animal or vegetable oil which will combine with an alkali to saponify and form a soap.
Fatigue Chunks Thick three-dimensional particles exceeding 50 microns indicating severe wear of gear teeth.
Fatigue Life The theoretical number of revolutions (or hours of operation) a bearing will last under a given constant load and speed before the first evidence of fatigue develops on one or more of the components.
Fatigue Platelets Normal particles between 20 and 40 microns found in gear box and rolling element bearing oil samples observed by analytical ferrography. A sudden increase in the size and quantity of these particles indicates excessive wear.
Fatigued A structural failure of the filter medium due to flexing caused by cyclic differential pressure.
Ferrography An analytical method of assessing machine health by quantifying and examining ferrous wear particles suspended in the lubricant or hydraulic fluid.
Fiber Grease A grease with a distinctly fibrous structure, which is noticeable when portions of the grease are pulled apart.
Film Strength Property of a lubricant that acts to prevent scuffing or scoring of metal parts.
Filter Any device or porous substance used as a strainer for cleaning fluids by removing suspended matter.
Filter Efficiency Method of expressing a filter's ability to trap and retain contaminants of a given size.
Filter Element The porous device which performs the actual process of filtration.
Filter Head An end closure for the filter case or bowl that contains one or more ports.
Filter Housing A ported enclosure that directs the flow of fluid through the filter element.
Filter Life Test A type of filter capacity test in which a clogging contaminant is added to the influent of a filter, under specified test conditions, to produce a given rise in pressure drop across the filter or until a specified reduction of flow is reached. Filter life may be expressed as test time required to reach terminal conditions at a specified contaminant addition rate.
Filtration The physical or mechanical process of separating insoluble particulate matter from a fluid, such as air or liquid, by passing the fluid through a filter medium that will not allow the particulates to pass through it.
Filtration (Beta) Ratio The ratio of the number of particles greater than a given size in the influent fluid to the number of particles greater than the same size in the effluent fluid.
Fire point (Clevelend Open Cup) The temperature to which a combustible liquid must be heated so that the released vapor will burn continuously when ignited under specified conditions.
Fire Resistant Fluid A fluid difficult to ignite which shows little tendency to propagate flame.
Fire-resistant Fluid Lubricant used especially in high-temperature or hazardous hydraulic applications. Three common types of fire-resistant fluids are: (1) water-petroleum oil emulsions, in which the water prevents burning of the petroleum constituent; (2) water-glycol fluids; and (3) non-aqueous fluids of low volatility, such as phosphate esters, silicones, and halogenated hydrocarbon-type fluids.
Fixed Displacement Pump A pump in which the displacement per cycle cannot be varied.
Flash Point (Cleveland Open Cup) The temperature to which a combustible liquid must be heated to give off sufficient vapor to form momentarily a flammable mixture with air when a small flame is applied under specified conditions. (ASTM Designation D 92.)
Floc Point The temperature at which wax or solids separate in an oil
Flow Control Valve A valve whose primary function is to control flow rate.
Flow Fatigue Rating The ability of a filter element to resist a structural failure of the filter medium due to flexing caused by cyclic differential pressure.
Flow Rate The volume, mass, or weight of a fluid passing through any conductor per unit of time.
Flowmeter A device which indicates either flow rate, total flow, or a combination of both.
Fluid A general classification including liquids and gases.
Fluid Compatibility The suitability of filtration medium and seal materials for service with the fluid involved.
Fluid Friction Friction due to the viscosity of fluids.
Fluid Opacity Related to the ability of a fluid to pass light.
Fluid Power Energy transmitted and controlled through use of a pressurized fluid.
Fluid Velocity The measured speed at which a fluid moves through the inside of a tube.
Flushing A fluid circulation process designed to remove contamination from the wetted surfaces of a fluid system.
Foam An agglomeration of gas bubbles separated from each other by a thin liquid film which is observed as a persistent phenomenon on the surface of a liquid.
Foam Inhibitor A substance introduced in a very small proportion to a lubricant or a coolant to prevent the formation of foam due to aeration of the liquid, and to accelerate the dissipation of any foam that may form
Foaming A frothy mixture of air and a petroleum product (e.g., lubricant, fuel oil) that can reduce the effectiveness of the product, and cause sluggish hydraulic operation, air binding of oil pumps, and overflow of tanks or sumps. Foaming can result from excessive agitation, improper fluid levels, air leaks, cavitation, or contamination with water or other foreign materials. Foaming can be inhibited with an antifoam agent. The foaming characteristics of a lubricating oil can be determined by blowing air through a sample at a specified temperature and measuring the volume of foam, as described in test method ASTM D 892.
Food Grade Lubricants Lubricants acceptable for use in meat, poultry and other food processing equipment, applications and plants. The lubricant types in food-grade applications are broken into categories based on the likelihood they will contact food. The USDA created the original food-grade designations H1, H2 and H3, which is the current terminology used. The approval and registration of a new lubricant into one of these categories depends on the ingredients used in the formulation.
Force Feed Lubrication A system of lubrication in which the lubricant is supplied to the bearing surface under pressure.
Four Ball Tester This name is frequently used to describe either of two similar laboratory machines, the Four-Ball Wear Tester and the Four-Ball EP Tester. These machines are used to evaluate a lubricants anti-wear qualities, frictional characteristics or load carrying capabilities. It derives its name from the four 1/2 inch steel balls used as test specimens. Three of the balls are held together in a cup filled with lubricant while the fourth ball is rotated against them.
Free Air Air at ambient temperature, pressure, relative humidity, and density.
Free Water Water droplets or globules in the system fluid that tend to accumulate at the bottom or top of the system fluid depending on the fluids specific gravity.
Fretting Wear phenomena taking place between two surfaces having oscillatory relative motion of small amplitude.
Fretting Corrosion Can take place when two metals are held in contact and subjected to repeated small sliding, relative motions. Other names for this type of corrosion include wear oxidation, friction oxidation, chafing, and brinelling.
Friction The resisting force encountered at the common boundary between two bodies when, under the action of an external force, one body, moves or tends to move relative to the surface of the other.
FTIR Fourier Transform Infrared Spectroscopy. A test where infrared light absorption is used for assessing levels of soot, sulfates, oxidation, nitro-oxidation, glycol, fuel, and water contaminants.
Fuel Dilution The amount of raw, unburned fuel that ends up in the crankcase of an engine. It lowers an oil's viscosity and flash point, creating friction-related wear almost immediately by reducing film strength.
Fuel Economy The amount of fuel required to move a machine over a given distance.
Full Flow Filter A filter that, under specified conditions, filters all influent flow.
Full Fluid Film Lubrication Presence of a continuous lubricating film sufficient to completely separate two surfaces, as distinct from boundary lubrication. Full-fluid-film lubrication is normally hydrodynamic lubrication, whereby the oil adheres to the moving part and is drawn into the area between the sliding surfaces, where it forms a pressure
Full-flow Filtration A system of filtration in which the total flow of a circulating fluid system passes through a filter.
FZG Four Square Gear Oil Test Used in developing industrial gear lubricants to meet equipment manufacturer's specifications. The FZG test equipment consists of two gear sets, arranged in a four square configuration, driven by an electric motor. The test gear set is run in the lubricant at gradually increased load stages until failure, which is the point at which a 10 milligram weight loss by the gear set is recorded. Also called Niemann Four Square Gear Oil Test.
G - Gage An instrument or device for measuring, indicating or comparing a physical characteristic.
Gage An instrument or device for measuring, indicating or comparing a physical characteristic.
Galling A form of wear in which seizing or tearing of the gear or bearing surface occurs.
Gas Turbine An engine that uses the energy of expanding gases passing through a multi-stage turbine to create rotating power.
Gasohol A blend of 10% anhydrous ethanol (ethyl alcohol) and 90% gasoline, by volume. Used as a motor fuel.
Gear A machine part which transmits motion and force by means of successively engaging projections, called teeth. The smaller gear of a pair is called the pinion; the larger, the gear. When the pinion is on the driving shaft, the gear set acts as a speed reducer; when the gear drives, the set acts as a speed multiplier. The basic gear type is the spur gear, or straight-tooth gear, with teethe cut parallel to the gear axis. Spur gears transmit power in applications utilizing parallel shafts. In this type of gear, the teeth mesh along their full length, creating a sudden shift in load from one tooth to the next, with consequent noise and vibration. This problem is overcome by the helical gear, which has teeth cut at an angle to the center of rotation, so that the load is transferred progressively along the length of the tooth from one edge of the gear to the other. When the shafts are not parallel, the most common gear type used is the bevel gear, with teeth cut on a sloping gear face, rather than parallel to the shaft. The spiral bevel gear has teeth cut at an angle to the plane of rotation, which, like the helical gear, reduces vibration and noise. A hypoid gear resembles a spiral bevel gear, except that the pinion is offset so that its axis does not intersect the gear axis; it is widely used in automobiles between the engine driveshaft and the rear axle. Offset of the axes of hypoid gears introduces additional sliding between the teeth, which, when combined with high loads, requires a high-quality EP oil. A worm gear consists of a spirally grooved screw moving against a tooth wheel; in this type of gear, where the load is transmitted across sliding, rather than rolling surfaces, compounded oils or EP oils are usually necessary to maintain effective lubrication.
Gear Oil A high-quality oil with good oxidation stability, load-carrying capacity, rust protection, and resistance to foaming, for service in gear housings and enclosed chain drives. Specially formulated industrial EP gear oils are used where highly loaded gear sets or excessive sliding action (as in worm gears) is encountered.
Gearbox (gear housing) A casing for gear sets that transmit power from one rotating shaft to another. A gear box has a number of functions: it is precisely bored to control gear and shaft alignment, it contains the gear oil, and it protects the gears and lubricant from water, dust, and other environmental contaminants. Gear boxes are used in a wide range of industrial, automotive, and home machinery. Not all gears are enclosed in gear boxes; some are open to the environment and are commonly lubricated by highly adhesive greases.
Generated Contaminant Caused by a deterioration of critical wetted surfaces and materials or by a breakdown of the fluid itself.
GPM Gallons per minute - Graphite A crystalline form of carbon having a laminar structure, which is used as a lubricant. It may be of natural or synthetic origin.
Graphite A crystalline form of carbon having a laminar structure, which is used as a lubricant. It may be of natural or synthetic origin.
Gravimetric Analysis A method of analysis whereby the dry weight of contaminant per unit volume of fluid can be measured showing the degree of contamination in terms of milligrams of contaminant per litre of fluid.
Gravity See Specific Gravity; API Gravity. - Gravity Separation A method of separating two components from a mixture. Under the influence of gravity, separation of immiscible phases (gas-solid, liquid-solid, liquid-liquid, solid-solid) allows the denser phase to settle out.
Gravity Separation A method of separating two components from a mixture. Under the influence of gravity, separation of immiscible phases (gas-solid, liquid-solid, liquid-liquid, solid-solid) allows the denser phase to settle out.
Grease A lubricant composed of an oil or oils thickened with a soap, soaps or other thickener to a semisolid or solid consistency.
Grease Fitting A small fitting which connects a grease gun and the component to be lubricated. The fitting is installed by a threaded connection, leaving a nipple to which the grease gun attaches.
Grease Gun A tool (normally hand-powered) which is used for lubrication tasks. By squeezing the trigger of the gun, grease is applied through an aperture to a specific point.
H - H1 Lubricant Food-grade lubricants used in food processing environments where there is some possibility of incidental food contact. Lubricant formulations may only be composed of one or more approved basestocks, additives and thickeners (if grease) listed in Guidelines of Security Code of Federal Regulations (CFR) Title 21, 178.3570.
H1 Lubricant Food-grade lubricants used in food processing environments where there is some possibility of incidental food contact. Lubricant formulations may only be composed of one or more approved basestocks, additives and thickeners (if grease) listed in Guidelines of Security Code of Federal Regulations (CFR) Title 21, 178.3570.
H2 Lubricant Lubricants used on equipment and machine parts in locations where there is no possibility that the lubricant or lubricated surface contacts food. Because there is not the risk of contacting food, these lubricants do not have a defined list of acceptable ingredients. They cannot, however, contain intentionally heavy metals such as antimony, arsenic, cadmium, lead, mercury or selenium. Also, the ingredients must not include substances that are carcinogens, mutagens, teratogens or mineral acids.
H3 Lubricant Also known as soluble or edible oil. These are used to clean and prevent rust on hooks, trolleys and similar equipment.
Hardness The resistance of a substance to surface abrasion.
Head An end closure for the filter case or bowl which contains one or more ports.
Heat Exchanger A device which transfers heat through a conducting wall from one fluid to another.
Heavy Ends The portions of a petroleum distillate fraction which are highest boiling, and therefore distill over last if the temperature is raised progressively.
Helical Gear A cylindrical gear wheel which has slanted teeth that follow the pitch surface in a helical manner.
Housing A ported enclosure which directs the flow of fluid through the filter element.
HVI High Viscosity Index, typically from 80 to 110 VI units.
Hybrid Bearing A bearing that consists of metal rings and ceramic balls.
Hydraulic Fluid Fluid serving as the power transmission medium in a hydraulic system. The most commonly used fluids are petroleum oils, synthetic lubricants, oil-water emulsions, and water-glycol mixtures. The principal requirements of a premium hydraulic fluid are proper viscosity, high viscosity index, anti-wear protection (if needed), good oxidation stability, adequate pour point, good demulsibility, rust inhibition, resistance to foaming, and compatibility with seal materials. Anti-wear oils are frequently used in compact, high-pressure, and capacity pumps that require extra lubrication protection.
Hydraulic Motor A device which converts hydraulic fluid power into mechanical force and motion by transfer of flow under pressure. It usually provided rotary mechanical motion.
Hydraulic Oil An oil specially suited for use as either the specific gravity or the API gravity of a liquid.
Hydraulic Pump A device which converts mechanical force and motion into hydraulic fluid power by means of producing flow.
Hydraulic System A system designed to transmit power through a liquid medium, permitting multiplication of force in accordance with Pascals law, which stated that a pressure exerted on a confined liquid is transmitted undiminished in all directions and acts with equal force on all equal areas. Hydraulic systems have six basic components: (1) a reservoir to hold the fluid supply; (2) a fluid to transmit the power; (3) a pump to move the fluid; (4) a valve to regulate pressure; (5) a directional valve to control the flow, and (6) a working component such as a cylinder and piston or a shaft rotated by pressurized fluid to turn hydraulic power into mechanical motion. Hydraulic systems offer several advantages over mechanical systems: They eliminate complicated mechanisms such as cams, gears, and levers; are less subject to wear; are usually more easily adjusted for control of speed and force; are easily adaptable to both rotary and liner transmission of power; and can transmit power over long distances and in any direction with small losses.
Hydraulics Engineering science pertaining to liquid pressure and flow.
Hydro Turbine A rotary engine whose energy is generated from moving water.
Hydrocarbons Compounds containing only carbon and hydrogen. Petroleum consists chiefly of hydrocarbons.
Hydrodynamic Lubrication A system of lubrication in which the shape and relative motion of the sliding surfaces causes the formation of a fluid film having sufficient pressure to separate the surfaces.
Hydrofinishing A process for treating raw extracted base stocks with hydrogen to saturate them for improved stability.
Hydrogenation In refining, the chemical addition of hydrogen to a hydrocarbon in the presence of a catalyst; a severe form of hydrogen treating. Hydrogenation may be either destructive or non-destructive. In the former case, hydrocarbon chains are ruptured (cracked) and hydrogen is added where the breaks have occurred. In the latter, hydrogen is added to a molecule that is unsaturated with respect ot hydrogen. In either case, the resulting products are highly stable. Temperatures and pressures in the hydrogenation process are usually greater than in hydrofining.
Hydrolysis Breakdown process that occurs in anhydrous hydraulic fluids as a result of heat, water, and metal catalysts (iron, steel, copper, etc.)
Hydrolytic Stability Ability of additives and certain synthetic lubricants to resist chemical decomposition (hydrolysis) in the presence of water.
Hydrometer An instrument for determining either the specific gravity of a liquid or the API gravity.
Hydrophilic Compounds with an affinity for water. - Hydrophobic Compounds that repel water.
Hydrophobic Compounds that repel water. - Hydrostatic Lubrication A system of lubrication in which the lubricant is supplied under sufficient external pressure to separate the opposing surfaces by a fluid film.
Hydrostatic Lubrication A system of lubrication in which the lubricant is supplied under sufficient external pressure to separate the opposing surfaces by a fluid film.
Hypoid Gear Lubricant A gear lubricant having extreme pressure characteristics for use with a hypoid type of gear as in the differential of an automobile.
Hypoid Gears Gears in which the pinion axis intersects the plane of the ring gear at a point below the ring-gear axle and above the outer edge of the ring gear, or above the ring-gear axle and below the outer edge of the ring gear.
I - ILMA The Independent Lubricant Manufacturers Association (ILMA) is a trade association of businesses engaged in compounding, blending, formulating, packaging, marketing, and distributing lubricants.
ILMA The Independent Lubricant Manufacturers Association (ILMA) is a trade association of businesses engaged in compounding, blending, formulating, packaging, marketing, and distributing lubricants.
ILSAC The International Lubricant Standardization and Approval Committee (ILSAC) is a joint committee of AAMA and JAMA members that assists in the development of new minimum oil performance standards.
Image Analyzer A sophisticated microscopic system involving a microscope, a television camera, a dedicated computer, and a viewing monitor similar to a television screen.
Immiscible Incapable of being mixed without separation of phases. Water and petroleum oil are immiscible under most conditions, although they can be made miscible with the addition of an emulsifier.
Incompatible Fluids Fluids which when mixed in a system, will have a deleterious effect on that system, its components or its operation.
Indicator A device which provides external evidence of sensed phenomena.
Industrial Lubricant Any petroleum or synthetic-base fluid or grease commonly used in lubricating industrial equipment, such as gears, turbines, and compressors.
Influent The fluid entering a component. - Infrared Analysis A form of absorption spectroscopy that identifies organic functional groups present in a used oil sample by measuring their light absorption at specific infrared wavelengths; absorbance is proportional to concentration. The test can indicate additive depletion, the presence of water, hydrocarbon contamination of a synthetic lubricant, oxidation, nitration, and glycol contamination from coolant. Fourier Transform Infrared (FTIR) permits the generation of complex curves from digitally represented data.
Infrared Analysis A form of absorption spectroscopy that identifies organic functional groups present in a used oil sample by measuring their light absorption at specific infrared wavelengths; absorbance is proportional to concentration. The test can indicate additive depletion, the presence of water, hydrocarbon contamination of a synthetic lubricant, oxidation, nitration, and glycol contamination from coolant. Fourier Transform Infrared (FTIR) permits the generation of complex curves from digitally represented data.
Infrared Spectra A graph of infrared energy absorbed at various frequencies in the additive region of the infrared spectrum. The current sample, the reference oil and the previous samples are usually compared.
Infrared Spectroscopy An analytical method using infrared absorption for assessing the properties of used oil and certain contaminants suspended therein. See FTIR.
Ingested Contaminants Environmental contaminant that ingresses due to the action of the system or machine.
Ingression Level Particles added per unit of circulating fluid volume.
Inhibitor Any substance that slows or prevents such chemical reactions as corrosion or oxidation.
In-line Filter A filter assembly in which the inlet, outlet and filter element axes are in a straight line.
Inside-mounted Seal A mechanical seal located inside the seal chamber with the pumped products pressure at its O.D.
Insolubles Particles of carbon or agglomerates of carbon and other material. Indicates deposition or dispersant drop-out in an engine. Not serious in a compressor or gearbox unless there has been a rapid increase in these particles.
Intensifier A device which converts low pressure fluid power into higher pressure fluid power.
Intercooler A device which cools a gas between the compressive steps of a multiple stage compressor.
Interfacial Tension (IFT) The energy per unit area present at the boundary of two immiscible liquids. It is usually expressed in dynes/cm (ASTM Designation D 971.)
Ion Exchange A transfer of ions between two electrolytes or between an electrolyte solution and a complex. The term normally denotes the processes of purification, separation and decontamination of aqueous and other ion-containing solutions with an insoluble (usually resinous) solid.
ISO International Standards Organization, sets viscosity reference scales.
ISO Solid Contaminant Code (ISO 4406) A code assigned on the basis of the number of particles per unit volume greater than 5 and 15 micrometers in size. Range numbers identify each increment in the particle population throughout the spectrum of levels.
ISO Standard 4021 The accepted procedure for extracting samples from dynamic fluid lines.
ISO viscosity grade A number indicating the nominal viscosity of an industrial fluid lubricant at 40 degrees C (104 degrees F) as defined by ASTM Standard Viscosity System for Industrial Fluid Lubricants D 2422. Essentially identical to ISO Standard 3448.
J - JIC Joint Industry Conference
JIC Joint Industry Conference - Joule A unit of work, energy, or heat. 1J (joule)=1 Nm) (Newton meter).
Joule A unit of work, energy, or heat. 1J (joule)=1 Nm) (Newton meter).
Journal That part of a shaft or axle that rotates or angularly oscillates in or against a bearing or about which a bearing rotates or angularly oscillates.
Journal Bearing A sliding type of bearing having either rotating or oscillatory motion and in conjunction with which a journal operates. In a full or sleeve type journal bearing, the bearing surface is 360 in extent. In a partial bearing, the bearing surface is less than 360 in extent, i.e., 150, 120, etc.
K - Karl Fischer Reagent Method The standard laboratory test to measure the water content of mineral base fluids. In this method, water reacts quantitatively with the Karl Fischer reagent. This reagent is a mixture of iodine, sulfur dioxide, pyridine, and methanol. When excess iodine exists, electric current can pass between two platinum electrodes or plates. The water in the sample reacts with the iodine. When the water is no longer free to react with iodine, an excess of iodine depolarizes the electrodes, signaling the end of the test.
Karl Fischer Reagent Method The standard laboratory test to measure the water content of mineral base fluids. In this method, water reacts quantitatively with the Karl Fischer reagent. This reagent is a mixture of iodine, sulfur dioxide, pyridine, and methanol. When excess iodine exists, electric current can pass between two platinum electrodes or plates. The water in the sample reacts with the iodine. When the water is no longer free to react with iodine, an excess of iodine depolarizes the electrodes, signaling the end of the test.
Kinematic Viscosity The time required for a fixed amount of an oil to flow through a capillary tube under the force of gravity. The unit of kinematic viscosity is the stoke or centistoke (1/100 of a stoke). Kinematic viscosity may be defined as the quotient of the absolute viscosity in centipoises divided by the specific gravity of a fluid, both at the same temperature--
L - Lacquer A deposit resulting from the oxidation and polymerization of fuels and lubricants when exposed to high temperatures. Similar to, but harder, than varnish.
Lacquer A deposit resulting from the oxidation and polymerization of fuels and lubricants when exposed to high temperatures. Similar to, but harder, than varnish.
Laminar Flow A flow situation in which fluid moves in parallel lamina or layers.
Laminar Particles Particles generated in rolling element bearings which have been flattened out by a rolling contact.
Lead Naphthenate A lead soap of naphthenic acids, the latter occurring naturally in petroleum.
Light Ends Low-boiling volatile materials in a petroleum fraction. They are often unwanted and undesirable, but in gasoline the proportion of light ends deliberately included are used to assist low-temperature starting.
Light Obscuration The degree of light blockage as reflected in the transmitted light impinging on the photodiode.
Lip Seal An elastomeric or metallic seal that prevents leakage in dynamic and static applications by a scraping or wiping action at a controlled interference between itself and the mating surface.
Liquid Any substance that flows readily or changes in response to the smallest influence. More generally, any substance in which the force required to produce a deformation depends on the rate of deformation rather than on the magnitude of the deformation.
Lithium Grease The most common type of grease today, based on lithium soaps.
Load-carrying Capacity Property of a lubricant to form a film on the lubricated surface, which resists rupture under given load conditions. Expressed as maximum load the lubricated system can support without failure or excessive wear.
Load-wear Index (LWI) Measure of the relative ability of a lubricant to prevent wear under applied loads; it is calculated from data obtained from the Four Ball EP Method. Formerly called mean Hertz load.
Log Logarithm (common) - Lubricant Any substance interposed between two surfaces in relative motion for the purpose of reducing the friction and/or the wear between them.
Lubricant Any substance interposed between two surfaces in relative motion for the purpose of reducing the friction and/or the wear between them.
Lubrication The control of friction and wear by the introduction of a friction-reducing film between moving surfaces in contact. The lubricant used can be a fluid, solid, or plastic substance.
Lubricator A device which adds controlled or metered amounts of lubricant into a pneumatic system.
Lubricity Ability of an oil or grease to lubricate; also called film strength.
LVI Low Viscosity Index, typically below 40 VI units.
M - M Meter
M Meter - Magnetic Filter A filter element that, in addition to its filter medium, has a magnet or magnets incorporated into its structure to attract and hold ferromagnetic particles.
Magnetic Filter A filter element that, in addition to its filter medium, has a magnet or magnets incorporated into its structure to attract and hold ferromagnetic particles.
Magnetic Plug Strategically located in the flow stream to collect a representative sample of wear debris circulating in the system: for example, engine swarf, bearing flakes, and fatigue chunks. The rate of buildup of wear debris reflects degradation of critical surfaces.
Magnetic Seal A seal that uses magnetic material (instead of springs or a bellows) to provide the closing force that keeps the seal faces together.
Magnetic Separator A separator that uses a magnetic field to attract and hold ferromagnetic particles.
Manifold A filter assembly containing multiple ports and integral relating components which services more than one fluid circuit.
Manifold Filter A filter in which the inlet and outlet port axes are at right angles, and the filter element axis is parallel to either port axis.
Material Safety Data Sheet (MSDS) A publication containing health and safety information on a hazardous product (including petroleum). The OSHA Hazard Communication Standard requires that an MSDS be provided by manufacturers to distributors or purchasers prior to or at the time of product shipment. An MSDS must include the chemical and common names of all ingredients that have been determined to be health hazards if they constitute 1% or greater of the products composition (0.1% for carcinogens). An MSDS also included precautionary guidelines and emergency procedures.
Mechanical Seal A device which works to join together systems or mechanisms in order to prevent leakage, contain pressure or exclude contamination.
Media Migration Material passed into the effluent stream composed of the materials making up the filter medium.
Medium The porous material that performs the actual process of filtration. The plural of this word is "media".
Metal Oxides Oxidized ferrous particles which are very old or have been recently produced by conditions of inadequate lubrication. Trend is important.
Metalworking Lubricant Any lubricant, usually petroleum-based, that facilitates the cutting or shaping of metal. Basic types of metalworking lubricants are: cutting and tapping fluids, drawing compounds, etc.
Micrometre See Micron. - Micron A unit of length. One Micron = 39 millionths of an inch (.000039"). Contaminant size is usually described in microns. Relatively speaking, a grain of salt is about 60 microns and the eye can see particles to about 40 microns. Many hydraulic filters are required to be efficient in capturing a substantial percentage of contaminant particles as small as 5 microns. A micron is also known as a micrometre, and exhibited as m
Micron A unit of length. One Micron = 39 millionths of an inch (.000039"). Contaminant size is usually described in microns. Relatively speaking, a grain of salt is about 60 microns and the eye can see particles to about 40 microns. Many hydraulic filters are required to be efficient in capturing a substantial percentage of contaminant particles as small as 5 microns. A micron is also known as a micrometre, and exhibited as m
Microscope Method A method of particle counting which measures or sizes particles using an optical microscope.
MIL Military - Mineral Oil Oil derived from a mineral source, such as petroleum, as opposed to oils derived from plants and animals.
Mineral Oil Oil derived from a mineral source, such as petroleum, as opposed to oils derived from plants and animals.
Mineral Seal Oil A distillation fraction between kerosene and gas oil, widely used as a solvent oil in gas adsorption processes, as a lubricant for the rolling of metal foil, and as a base oil in many specialty formulations. Mineral seal oil takes its name not from any sealing function but from the fact that it originally replaced oil derived from seal blubber for use as an illuminant for signal lamps and lighthouses.
Miscible Capable of being mixed in any concentration without separation of phases; e.g., water and ethyl alcohol are miscible.
Mixed Film A type of lubrication that features a combination of full-film and thin-film elements.
Mold (release) Lubricant A compound, often of petroleum origin, for coating the interiors of molds for glass and ceramic products. The mold lubricant facilitates removal of the molded object from the mold, protects the surface of the mold, and reduces or eliminates the need for cleaning it.
Moly Molybdenum disulfide, a solid lubricant and friction reducer, colloidally dispersed in some oils and greases.
Molybdenum Disulfide A black, lustrous powder (MoS2) that serves as a dry-film lubricant in certain high-temperature and high-vacuum applications. It is also used in the form of pastes to prevent scoring when assembling press-fit parts, and as an additive to impart residual lubrication properties to oils and greases. Molybdenum disulfide is often called moly or molysulfide.
Motor A device which converts fluid power into mechanical force and motion. It usually provides rotary mechanical motion.
Motor Bearing A bearing which supports the crankshaft in an internal-combustion engine. It is a support or guide by means of which a moving part is positioned with respect to the other parts of a mechanism.
Motor Oil Oil that is used to lubricate the moving components of an internal-combustion engine.
MTBF Mean Time Between Failures. - Multigrade Oil An oil meeting the requirements of more than one SAE viscosity grade classification, and may therefore be suitable for use over a wider temperature range than a single-grade oil.
Multigrade Oil An oil meeting the requirements of more than one SAE viscosity grade classification, and may therefore be suitable for use over a wider temperature range than a single-grade oil.
Multipass Test Filter performance tests in which the contaminated fluid is allowed to recirculate through the filter for the duration of the test. Contaminant is usually added to the test fluid during the test. The test is used to determine the Beta-Ratio (q.v.) of an element.
N - Naphthenic A type of petroleum fluid derived from naphthenic crude oil, containing a high proportion of closed-ring methylene groups.
Naphthenic A type of petroleum fluid derived from naphthenic crude oil, containing a high proportion of closed-ring methylene groups.
NAS National Aerospace Standard - NASA National Aeronautics and Space Administration
NASA National Aeronautics and Space Administration - NEC National Electrical Code
NEC National Electrical Code - Needle Bearing A rolling type of bearing containing rolling elements that are relatively long compared to their diameter.
Needle Bearing A rolling type of bearing containing rolling elements that are relatively long compared to their diameter.
NEMA National Electrical Manufacturers Association - Neutralization Number A measure of the total acidity or basicity of an oil; this includes organic or inorganic acids or bases or a combination thereof (ASTM Designation D974-58T)
Neutralization Number A measure of the total acidity or basicity of an oil; this includes organic or inorganic acids or bases or a combination thereof (ASTM Designation D974-58T)
Newtonian Fluid A fluid with a constant viscosity at a given temperature regardless of the rate of shear. Single-grade oils are Newtonian fluids. Multigrade oils are NON-Newtonian fluids because viscosity varies with shear rate.
NFPA National Fluid Power Association - Nitration Nitration products are formed during the fuel combustion process in internal combustion engines. Most nitration products are formed when an excess of oxygen is present. These products are highly acidic, form deposits in combustion areas and rapidly accelerate oxidation.
Nitration Nitration products are formed during the fuel combustion process in internal combustion engines. Most nitration products are formed when an excess of oxygen is present. These products are highly acidic, form deposits in combustion areas and rapidly accelerate oxidation.
Nitrous Oxide A chemical compound made up of nitrogen and oxygen, N2O. It is a liquid that turns into a gas when injected into an engine.
NLGI National Lubricating Grease Institute. A trade association whose main interest is grease and grease technology. NLGI is best known for its system of rating greases by penetration.
NLGI Automotive Grease Classifications Automotive lubricating grease quality levels established jointly by SAE, ASTM and NLGI. There are several categories in two classifications: Chassis Lubricants and Wheel bearing Lubricants. Quality or performance levels within each category are defined by ASTM tests.
NLGI Consistency Grades Simplified system established by the National Lubricating Grease Institute (NLGI) for rating the consistency of grease.
Nominal Filtration Rating An arbitrary micrometer value indicated by a filter manufacturer. Due to lack of reproducibility this rating is deprecated.
Non-Newtonian Fluid Fluid, such as a grease or a polymer-containing oil (e.g., multi-grade oil), in which shear stress is not proportional to shear rate.
Nonwoven Medium A filter medium composed of a mat of fibers.
Normal Paraffin A hydrocarbon consisting of molecules in which any carbon atom is attached to no more than two other carbon atoms; also called straight chain paraffin and linear paraffin.
O - Obliteration A synergistic phenomenon of both particle silting and polar adhesion. When water and silt particles co-exist in a fluid containing long-chain molecules, the tendency for valves to undergo obliteration increases.
Obliteration A synergistic phenomenon of both particle silting and polar adhesion. When water and silt particles co-exist in a fluid containing long-chain molecules, the tendency for valves to undergo obliteration increases.
Oil A greasy, unctuous liquid of vegetable, animal, mineral or synthetic origin.
Oil Analysis The routine activity of analyzing lubricant properties and suspended contaminants for the purpose of monitoring and reporting timely, meaningful and accurate information on lubricant and machine condition.
Oil Change The act of replacing dirty oil with clean oil.
Oil Consumption The amount of lubricating fluid that is consumed by a machine, production line, plant or company over a given period of time.
Oil Consumption Ratio Annual oil purchases divided by machine charge volume. For example, if you purchased 10,000 gallons of oil in one year and the total amount of oil that all of your machine holds is 4,200 gallons, your consumption ratio is 2.4.
Oil Drain A large bolt or plug that secures the drain hole in the oil pan. It is generally fitted with a gasket or O-ring to prevent leakage.
Oil Filter A device which removes the inherent or introduced impurities from the oil that lubricates an internal-combustion engine.
Oil Flushing A fluid circulation process that is designed to remove contamination and decomposition from a lubrication-based system.
Oil Mist Lubrication A method of lubricant delivery in which oil is piped throughout the machine to desired locations and dispensed with a spray nozzle. Oil mist systems are employed to cool and lubricate many machine parts at once.
Oil Mist System A device which delivers lubricant to multiple machine parts at once via a setup that includes piping and a spray nozzle.
Oil Oxidation Occurs when oxygen attacks petroleum fluids. The process is accelerated by heat, light, metal catalysts and the presence of water, acids, or solid contaminants. It leads to increased viscosity and deposit formation.
Oil Ring A loose ring, the inner surface of which rides a shaft or journal and dips into a reservoir of lubricant from which it carries the lubricant to the top of a bearing by its rotation with the shaft.
Oil Sampling A procedure which involves the collection of a volume of fluid from lubricated or hydraulic machinery for the purpose of performing oil analysis. Samples are typically drawn into a clean bottle which is sealed and sent to a laboratory for analytical work.
Oiler A device for once-through lubrication. Three common types of oilers are: drop-feed, wick-feed, and bottle-feed; all depend on gravity to induce a metered flow of oil to the bearing. The drop-feed oiler delivers oil from the bottom of a reservoir to a bearing one drop at a time; flow rate is controlled by a needle valve at the top of the reservoir. In a wick-feed oiler, the oil flows through a wick and drops from the end of the wick into the bearing; feed is regulated by chaining the number of strands, by raising or lowering the oil level, or by applying pressure to the wick. In a bottle-feed oiler, a vacuum at the top of the jar keeps the fluid from running out; as tiny bubbles of air enter, the vacuum is reduced and a small amount of oil enters the bearing or is added to a reservoir from wick the bearing is lubricated.
Oiliness That property of a lubricant that produces low friction under conditions of boundary lubrication. The lower the friction, the greater the oiliness.
Oiliness Agent An additive, usually polar in nature, used to improve the lubricity of a mineral oil. Now usually called a boundary lubrication additive.
Open bubble point (boil point) The differential gas pressure at which gas bubbles are profusely emitted from the entire surface of a wetted filter element under specified test conditions.
Open Gear A gear that is exposed to the environment, rather than being housed in a protective gear box. Open gears are generally large, heavily loaded, and slow moving. They are found in such applications as mining and construction machinery, punch presses, plastic and rubber mills, tube mills, and rotary kilns. Open gears require viscous, adhesive lubricants that bond to the metal surfaces and resist run-off. Such lubricants are often called gear shields. Top-quality lubricants for such applications are specially formulated to protect the gears against the effects of water and other contaminants.
OSHA Occupational Safety and Health Administration - Outside-mounted Seal A mechanical seal with its seal head mounted outside the seal chamber that holds the fluid to be sealed. Outside seals have the pumped fluids pressure at their I.D.
Outside-mounted Seal A mechanical seal with its seal head mounted outside the seal chamber that holds the fluid to be sealed. Outside seals have the pumped fluids pressure at their I.D.
Oxidation Inhibitor Substance added in small quantities to a petroleum product to increase its oxidation resistance, thereby lengthening its service or storage life; also called anti-oxidant. An oxidation inhibitor may work in one of these ways: (1) by combining with and modifying peroxides (initial oxidation products) to render them harmless, (2) by decomposing the peroxides, or (3) by rendering an oxidation catalyst inert.
Oxidation Stability Ability of a lubricant to resist natural degradation upon contact with oxygen.
P - P Pressure - psi
P Pressure - psi - PAG Synthetic Fluid Polyalkaline glycol have excellent oxidative and thermal stability, very high VI, excellent film strength and an extremely low tendency to leave deposits on machine surfaces. The low deposit-forming tendency is really due to two properties the oils ability to dissolve deposits and the fact that the oil burns clean. So when they are exposed to a very hot surface or subjected to micro-dieseling by entrained air, PAGs are less likely to leave residue that will form deposits. PAGs may also be the only type of base oil with significantly lower fluid friction, which may allow for energy savings. The other unique property of PAGs is the ability to absorb a great deal of water and maintain lubricity. There are actually two different types of PAGs one demulisifies and the other absorbs water. The most common applications for PAGs are compressors and critical gearing applications. The negatives of PAGs are their very high cost and the potential to be somewhat hydrolytically unstable.
PAG Synthetic Fluid Polyalkaline glycol have excellent oxidative and thermal stability, very high VI, excellent film strength and an extremely low tendency to leave deposits on machine surfaces. The low deposit-forming tendency is really due to two properties the oils ability to dissolve deposits and the fact that the oil burns clean. So when they are exposed to a very hot surface or subjected to micro-dieseling by entrained air, PAGs are less likely to leave residue that will form deposits. PAGs may also be the only type of base oil with significantly lower fluid friction, which may allow for energy savings. The other unique property of PAGs is the ability to absorb a great deal of water and maintain lubricity. There are actually two different types of PAGs one demulisifies and the other absorbs water. The most common applications for PAGs are compressors and critical gearing applications. The negatives of PAGs are their very high cost and the potential to be somewhat hydrolytically unstable.
PAO Synthetic Fluid Polyalphaolefins, often called synthetic hydrocarbons, are probably the most common type of synthetic base oil used today. They are moderately priced, provide excellent performance and have few negative attributes. PAO base oil is similar to mineral oil. The advantage comes from the fact that it is built, rather than extracted and modified, making it more pure. Practically all of the oil molecules are the same shape and size and are completely saturated. The potential benefits of PAOs are improved oxidative and thermal stability, excellent demulsibility and hydrolytic stability, a high VI, and very low pour point. Most of the properties make PAOs a good selection for temperature extremes both high operating temperatures and low start-up temperatures. Typical applications for PAOs are engine oils, gear oils and compressor oils. The negative attributes of PAOs are the price and poor solubility. The low inherent solubility of PAOs creates problems for formulators when it comes to dissolving additives. Likewise, PAOs cannot suspend potential varnish-forming degradation by-products, although they are less prone to create such material.
Paper Chromatography A method which involves placing a drop of fluid on a permeable piece of paper and noting the development and nature of the halos, or rings, surrounding the drop through time. The roots of this test can be traced to the 1940s, when railroads used the "blotter spot" tests.
Paraffin Any hydrocarbon identified by saturated straight (normal) or branched (iso) carbon chains; also called an alkane. The generalized paraffinic molecule can be symbolized by the formula CnH2n+2. Paraffins are relatively non-reactive and have excellent oxidation stability. In contrast to naphthenic oils, paraffinic lubricating oils have relatively high wax content and pour point, and generally have a high viscosity index (VI.). Paraffinic solvents are generally lower in solvency than naphthenic or aromatic solvents.
Paraffinic A type of petroleum fluid derived from paraffinic crude oil and containing a high proportion of straight chain saturated hydrocarbons. Often susceptible to cold flow problems.
Parallel Systems Lubrication systems where the dispensing devices are connected to the main line in parallel. Each dispensing device operates independent of any other in the system.
Particle Count The number of particles present greater than a particular micron size per unit volume of fluid often stated as particles > 10 microns per milliliter.
Particle Counter An instrument that detects and counts particles found in a fluid such as oil.
Particle Counting A microscopic technique that enables the visual counting of particles in a known quantity of fliud. The count identifies the number of particles present greater than a particular micron size per unit volume of fluid often stated as particles > 10 microns per milliliter.
Particle Density An important parameter in establishing an entrained particle's potential to impinge on control surfaces and cause erosion.
Particle Erosion Occurs when fluid-entrained particles moving at high velocity pass through orifices or impinge on metering surfaces or sharp angle turns.
Particle Impingement Erosion A particulate wear process where high velocity, fluid-entrained particles are directed at target surfaces.
Particulates Particles made up of a wide range of natural materials (e.g., pollen, dust, resins), combined with man-made pollutant (e.g., smoke particles, metallic ash); in sufficient concentrations, particulates can be a respiratory irritant.
Pascal Unit of pressure in the metric (SI) system.
Pascals Law A pressure applied to a confined fluid at rest is transmitted with equal intensity throughout the liquid and that pressure is considered to act at right angles to each surface contacted by the fluid.
Patch Test A method by which a specified volume of fluid is filtered through a membrane filter of known pore structure. All particulate matter in excess of an "average size," determined by the membrane characteristics, is retained on its surface. Thus, the membrane is discolored by an amount proportional to the particulate level of the fluid sample. Visually comparing the test filter with standard patches of known contamination levels determines acceptability for a given fluid.
PCB Polychlorinated biphenyl, a class of synthetic chemicals consisting of a homologous series of compounds beginning with monochlorobiphenyl and ending with decachlorobiphenyl. PCBs do not occur naturally in petroleum, but have been found as contaminants in used oil. PCBs have been legally designated as a health hazard, and any oil so contaminated bust be handled in strict accordance with state and federal regulations.
PCV System An abbreviation for "positive crankcase ventilation system". This is a system which prevents the vapors of a crankcase from being directly discharged into the atmosphere.
PCV Valve A Positive Crankcase Ventilation (PCV) valve is a one-way valve that ensures the continual flow and evacuation of gases from the crankcase into the engine.
Permeability The relationship of flow per unit area to differential pressure across a filter medium.
Petrochemical Any chemical substance derived from crude oil or its products, or from natural gas. Some petrochemical products may be identical to others produced from other raw materials such as coal and producer gas.
Phenol A white, crystalline compound (C6H5OH) derived from benzene, used in the manufacture of phenolic resins, weed killers, plastics, disinfectants; also used in solvent extraction, a petroleum refining process. Phenol is a toxic material; skin contact must be avoided.
Phosphate Ester Any of a group of synthetic lubricants having superior fire resistance. A phosphate ester generally has poor hydrolytic stability, poor compatibility with mineral oil, and a relatively low viscosity index (VI). It is used as a fire-resistant hydraulic fluid in high-temperature applications.
Pinion The smaller of two mating or meshing gears; can be either the driving or the driven gear.
Pitch Line An imaginary line that divides the upper and lower halves of gear teeth while in the contact area.
Pitting A form of extremely localized attack characterized by holes in the metal. Pitting is one of the most destructive and insidious forms of corrosion. Depending on the environment and the material, a pit may take months, or even years, to become visible.
Plain Bearing A relatively simple and inexpensive bearing typically made of two parts. A rotary plain bearing can be just a shaft running through a hole. A simple linear bearing can be a pair of flat surfaces designed to allow motion.
Pleated Filter A filter element whose medium consists of a series of uniform folds and has the geometric form of a cylinder, cone, disc, plate, etc. Synonymous with "convoluted" and "corrugated".
PNA (polynuclear aromatic) Any of numerous complex hydrocarbon compounds consisting of three or more benzene rings in a compact molecular arrangement. Some types of PNAs are formed in fossil fuel combustion and other heat processes, such as catalytic cracking.
Pneumatics Engineering science pertaining to gaseous pressure and flow.
Poise (absolute viscosity) A measure of viscosity numerically equal to the force required to move a plane surface of one square centimeter per second when the surfaces are separated by a layer of fluid one centimeter in thickness. It is the ratio of the shearing stress to the shear rate of a fluid and is expressed in dyne seconds per square centimeter (DYNE SEC/CM2); 1 centipoise equals .01 poise.
Polar Compound A chemical compound whose molecules exhibit electrically positive characteristics at one extremity and negative characteristics at the other. Polar compounds are used as additives in many petroleum products. Polarity gives certain molecules a strong affinity for solid surfaces; as lubricant additives (oiliness agents), such molecules plate out to form a tenacious, friction-reducing film. Some polar molecules are oil-soluble at one end and water-soluble at the other end; in lubricants, they act as emulsifiers, helping to form stable oil-water emulsions. Such lubricants are said to have good metal-wetting properties. Polar compounds with a strong attraction for solid contaminants act as detergents in engine oils by keeping contaminants finely dispersed.
Polishing (bore) Excessive smoothing of the surface finish of the cylinder bore or cylinder liner in an engine to a mirror-like appearance, resulting in depreciation of ring sealing and oil consumption performance.
Polyalkylene Glycol Mixtures of condensation polymers of ethylene oxide and water. They are any of a family of colorless liquids with high molecular weight that are soluble in water and in many organic solvents. They are used in detergents and as emulsifiers and plasticizers. PAG-based lubricants are used in diverse applications where petroleum oil-based products do not provide the desired performance and because they are fire-resistant and will not harm workers or the environment.
Polyglycols Polymers of ethylene or propylene oxides used as a synthetic lubricant base. Properties include very good hydrolytic stability, high viscosity index (VI), and low volatility. Used particularly in water emulsion fluids.
Polymer A substance formed by the linkage (polymerization) of two or more simple, molecules, called monomers, to form a single larger molecule having the same elements in the same proportions as the original monomers; i.e. each monomer retains its structural identity. A polymer may be liquid or solid; solid polymers may consist of millions of repeated linked units. A polymer made from two or more similar monomers is called a copolymer; a copolymer composed of three different types of monomers is a terpolymer. Natural rubber and synthetic rubbers are examples of polymers. Polymers are commonly used as viscosity index improvers in multi-grade oils and tackifiers in lubricating greases.
Polymerization The chemical combination of similar-type molecules to form larger molecules.
Polyol Ester A synthetic lubricant base, formed by reacting fatty acids with a polyol (such as a glycol) derived from petroleum. Properties include good oxidation stability at high temperatures and low volatility. Used in formulating lubricants for turbines, compressors, jet engines, and automotive engines.
Polyolefin A polymer derived by polymerization of relatively simple olefins. Polyethylene and polyisoprene are important polyolefins.
Pore A small channel or opening in a filter medium which allows passage of fluid.
Pore Size Distribution The ratio of the number of effective holes of a given size to the total number of effective holes per unit area expressed as a percent and as a function of hole size.
Porosity The ratio of pore volume to total volume of a filter medium expressed as a percent.
Pour Point Lowest temperature at which an oil or distillate fuel is observed to flow, when cooled under conditions prescribed by test method ASTM D 97. The pour point is 3C (5F) above the temperature at which the oil in a test vessel shows no movement when the container is held horizontally for five seconds.
Pour Point Depressant An additive which retards the adverse effects of wax crystallization, and lowers the pour point.
Pour Stability The ability of a pour depressed oil to maintain its original ASTM pour point when subjected to long-term storage at low temperature approximating winter conditions.
Power Unit A combination of pump, pump drive, reservoir, controls and conditioning components which may be required for its application.
PPM Parts per million (1/ppm = 0.000001). Generally by weight. 100 ppm = 0.01%; 10,000 ppm = 1%
Predictive Maintenance A type of condition-based maintenance emphasizing early prediction of failure using non-destructive techniques such as vibration analysis, thermography, and wear debris analysis.
Pressure Force per unit area, usually expressed in pounds per square inch.
Pressure Control Valve A pressure control valve whose primary function is to limit system pressure.
Pressure Drop Resistance to flow created by the element (media) in a filter. Defined as the difference in pressure upstream (inlet side of the filter) and downstream (outlet side of the filter).
Pressure Gage Pressure differential above or below atmospheric pressure.
Pressure Indicator An indicator that signals pressure conditions.
Pressure Line Filter A filter located in a line conducting working fluid to a working device or devices.
Pressure Switch An electric switch operated by fluid pressure.
Pressure, absolute The sum of atmospheric and gage pressures.
Preventive Maintenance Maintenance performed according to a fixed schedule involving the routine repair and replacement of machine parts and components.
Proactive Maintenance A maintenance strategy for stabilizing the reliability of machines or equipment. Its central theme involves directing corrective actions aimed at failure root causes, not active failure symptoms, faults, or machine wear conditions. A typical proactive maintenance regiment involves three steps: (1) setting a quantifiable target or standard relating to a root cause of concern (e.g., a target fluid cleanliness level for a lubricant), (2) implementing a maintenance program to control the root cause property to within the target level (e.g., routine exclusion or removal of contaminants), and (3) routine monitoring of the root cause property using a measurement technique (e.g., particle counting) to verify the current level is within the target.
Process Oil An oil that serves as a temporary or permanent component of a manufactured products. Aromatic process oils have good solvency characteristics; their applications include proprietary chemical formulations, ink oils, and extenders in synthetic rubbers. Naphthenic process oils are characterized by low pour points and good solvency properties. Paraffinic process oils are characterized by low aromatic content and light color.
PSI Pounds per square inch - PSIA Pounds per square inch absolute. (PSIG + 14.696)
PSIA Pounds per square inch absolute. (PSIG + 14.696)
PSID Pounds per square inch differential. - PSIG Pounds per square inch gauge (PSIA - 14.696)
PSIG Pounds per square inch gauge (PSIA - 14.696)
Pump A device which converts mechanical force and motion into hydraulic fluid power.
Pumpability The low temperature, low shear stress-shear rate viscosity characteristics of an oil that permit satisfactory flow to and from the engine oil pump and subsequent lubrication of moving components.
Pusher seal A mechanical seal in which the secondary seal is pushed along the shaft or sleeve to compensate for misalignment and face wear.
Q - Q Flow rate - GPM
Q Flow rate - GPM - Quenching Oil (Also called heat treating oil) a high-quality, oxidation-resistant petroleum oil used to cool metal parts during their manufacture, and is often preferred to water because the oils slower heat transfer lessens the possibility of cracking or warping of the metal. A quenching oil must have excellent oxidation and thermal stability, and should yield clean parts, essentially free of residue. In refining terms, a quenching oil is an oil introduced into high temperature vapors of cracked (see cracking) petroleum fractions to cool them.
Quenching Oil (Also called heat treating oil) a high-quality, oxidation-resistant petroleum oil used to cool metal parts during their manufacture, and is often preferred to water because the oils slower heat transfer lessens the possibility of cracking or warping of the metal. A quenching oil must have excellent oxidation and thermal stability, and should yield clean parts, essentially free of residue. In refining terms, a quenching oil is an oil introduced into high temperature vapors of cracked (see cracking) petroleum fractions to cool them.
Quick Disconnect Coupling A coupling which can quickly join or separate a fluid line without the use of tools or special devices.
R - R & O (Rust and Oxidation Inhibited) A term applied to highly refined industrial lubricating oils formulated for long service in circulating lubrication systems, compressors, hydraulic systems, bearing housing, gear boxes, etc. The finest R&O oils are often referred to as turbine oils.
R & O (Rust and Oxidation Inhibited) A term applied to highly refined industrial lubricating oils formulated for long service in circulating lubrication systems, compressors, hydraulic systems, bearing housing, gear boxes, etc. The finest R&O oils are often referred to as turbine oils.
Rate of Shear The difference between the velocities along the parallel faces of a fluid element divided by the distance between the faces.
Rated Flow The maximum flow that the power supply system is capable of maintaining at a specific operating pressure.
Rated Pressure The qualified operating pressure which is recommended for a component or a system by the manufacturer.
Reducer A connector having a smaller line size at one end than the other.
Refining A series of processes for converting crude oil and its fractions to finished petroleum products. Following distillation, a petroleum fraction may undergo one or more additional steps to purify or modify it. These refining steps include; thermal cracking, catalytic cracking, polymerization, alkylation, reforming, hydrocracking, hydroforming, hydrogenation, hydrogen treating, hydrofining, solvent extraction, dewaxing, deoiling, acid treating, clay filtration, and deasphalting. Refined lubricating oils may be blended with other lube stocks, and additives may be incorporated, to impart special properties.
Refraction The change of direction or speed of light as it passes from one medium to another.
Refrigeration Compressor A special type of compressor typically used for refrigeration, heat pumping and air conditioning. They are made to turn low-pressure gases into high-pressure and high-temperature gases. The three main types of refrigeration compressors are screw compressors, scroll compressors and piston compressors.
Refrigerator Oil The lubricant added to the working fluid in an expansion-type cooling unit which serves to lubricate the pump mechanism.
Remaining Useful Life An opinion (based on data, observations, history, records, exposure, etc.) of the number of years before a fluid, system or component will require replacement or reconditioning.
Rerefining A process of reclaiming used lubricant oils and restoring them to a condition similar to that of virgin stocks by filtration, clay adsorption or more elaborate methods.
Reservoir A container for storage of liquid in a fluid power system.
Reservoir Filter A filter installed in a reservoir in series with a suction or return line. Also known as sump filter.
Residual Dirt Capacity The dirt capacity remaining in a service loaded filter element after use, but before cleaning, measured under the same conditions as the dirt capacity of a new filter element.
Return Line A location in a line conducting fluid from working device to reservoir.
Return Line Filtration Filters located upstream of the reservoir but after fluid has passed through the system's output components (cylinders, motors, etc.).
ReynoldsNumber A numerical ratio of the dynamic forces of mass flow to the shear stress due to viscosity. Flow usually changes from laminar to turbulent between Reynolds Number 2,000 and 4,000.
Rheology The study of the deformation and flow of matter in terms of stress, strain, temperature, and time. The rheological properties of a grease are commonly measured by penetration and apparent viscosity.
Ring Lubrication A system of lubrication in which the lubricant is supplied to the bearing by an oil ring.
Ring Sticking Freezing of a piston ring in its groove in a piston engine or reciprocating compressor due to heavy deposits in the piston ring zone.
Rings Circular metallic elements that ride in the grooves of a piston and provide compression sealing during combustion. Also used to spread oil for lubrication.
Roller Bearing An antifriction bearing comprising rolling elements in the form of rollers.
Rolling Element Bearing A friction-reducing bearing that consists of a ring-shaped track that contains free-revolving metal balls. A rotating shaft or other part turns against such a bearing.
Rolling Oil An oil used in hot- or cold-rolling of ferrous and non-ferrous metals to Facilitate feed of the metal between the work rolls, improve the plastic deformation of the metal, conduct heat from the metal, and extend the life of the work rolls. Because of the pressures involved, a rolling oil may be compounded or contain EP additives. In hot rolling, the oil may also be emulsifieable.
Roll-off Cleanliness The fluid system contamination level at the time of release from an assembly or overhaul line. Fluid system life can be shortened significantly by full-load operation under a high fluid contamination condition for just a few hours. Contaminant implanted and generated during the break-in period can devastate critical components unless removed under controlled operating and high performance filtering conditions.
Rotary Seal A mechanical seal which rotates with a shaft and is used with a stationary mating ring.
Rotating Equipment Equipment that moves liquids, solids or gases through a system of drivers (turbines, motors, engines), driven components (compressors, pumps), transmission devices (gears, clutches, couplings) and auxiliary equipment (lube and seal systems, cooling systems, buffer gas systems).
Rotating Pressure Vessel Oxidation Test (RPVOT) The Rotating Pressure Vessel Oxidation Test measures an oil's oxidation stability. The oil sample is placed in a vessel containing a polished copper coil. The vessel is then charged with oxygen and placed in a bath at a constant temperature of 150 degrees Celsius. Stability is expressed in terms of the time it takes to achieve a pressure drop of 25.4 pounds per square inch (psig) pressure drop from maximum pressure.
Rust Inhibitor A type of corrosion inhibitor used in lubricants to protect surfaces against rusting.
Rust Prevention Test (turbine oils) A test for determining the ability of an oil to aid in preventing the rusting of ferrous parts in the presence of water.
S - SAE Society of Automotive Engineers, an organization serving the automotive industry.
SAE Society of Automotive Engineers, an organization serving the automotive industry.
SAE Port A straight thread port used to attach tube and hose fittings. It employs an O ring compressed in a wedge-shaped cavity. A standard of the Society of Automotive Engineers J514 and ANSI/B116.1
SAE Viscosity The viscosity classification of a motor oil according to the system developed by the Society of Automotive Engineers and now in general use. Winter grades are defined by viscosity measurements at low temperatures and have W as a suffix, while Summer grades are defined by viscosity at 100C and have no suffix. Multigrade oils meet both a winter and a summer definition and have designations such as SAE 10W-30, etc.
Sample Preparation Fluid factors that can enhance the accuracy of the particulate analysis. Such factors include particle dispersion, particle settling, and sample dilution.
Saponification Number The number of milligrams of potassium hydroxide (KOH) that combine with one gram of oil under conditions specified by test method ASTM D 94. Saponification number is an indication of the amount of fatty saponifiable material in compounded oil. Caution must be used in interpreting test results if certain substances - such as sulfur compounds or halogens - are present in the oil, since these also react with KOH, thereby increasing the apparent Saponification number.
Saturation Level The amount of water that can dissolve in a fluid.
Saybolt Universal Viscosity (SUV) or Saybolt Universal Seconds, (SUS) The time in seconds required for 60 cubic centimeters of a fluid to flow through the orifice of the Standard Saybolt Universal Viscometer at a given temperature under specified conditions. (ASTM Designation D 88.)
Scoring Distress marks on sliding metallic surfaces in the form of long, distinct scratches in the direction of motion. Scoring is an advanced stage of scuffing.
Scuffing Abnormal engine wear due to localized welding and fracture. It can be prevented through the use of antiwear, extreme-pressure and friction modifier additives.
Scuffing Particles Large twisted and discolored metallic particles resulting from adhesive wear due to complete lubricant film breakdown.
Seal A device designed to prevent the movement of fluid from one area to another, or to exclude contaminants.
Seal Assembly A group of parts, or a unitized assembly, that includes sealing surfaces, provisions for initial loading, and a secondary sealing mechanism that accommodates the radial and axial movement necessary for installation and operation.
Seal Chamber The area between the seal chamber bore and a shaft in which a mechanical seal is installed.
Seal Face It is either of the two lapped surfaces in a mechanical seal assembly forming the primary seal.
Seal Face Width The radial distance from the inside edge to the outside edge of the sealing face.
Seal Swell (rubber swell) The swelling of rubber (or other elastomers) gaskets, or seals when exposed to petroleum, synthetic lubricants, or hydraulic fluids. Seal materials vary widely in their resistance to the effect of such fluids. Some seals are designed so that a moderate amount of swelling improves sealing action.
Sealed Motor Bearing These bearings have rubbing seals that seal against recesses in the inner ring shoulder. They are lubricated for life. Under extreme conditions, their life can be short.
Semisolid Any substance having the attributes of both a solid and a liquid. Similar to semiliquid but being more closely related to a solid than a liquid. More generally, any substance in which the force required to produce a deformation depends both on the magnitude and on the rate of the deformation.
Servovalve A valve which modulates output as a function of an input command.
Settling Tank A tank in which liquid is stored until particles suspended in the liquid sink to the bottom.
Severe Sliding Large ferrous particles which are produced by sliding contacts. Trend is important to determine whether abnormal wear is taking place.
Shear Rate Rate at which adjacent layers of fluid move with respect to each other, usually expressed as reciprocal seconds.
Shear Stress Frictional force overcome in sliding one "layer" of fluid along another, as in any fluid flow. The shear stress of a petroleum oil or other Newtonian fluid at a given temperature varies directly with shear rate (velocity). The ratio between shear stress and shear rate is constant; this ratio is termed viscosity of a Newtonian fluid, the greater the shear stress as a function of rate of shear. In a non-Newtonian fluid
Silt Contaminant particles 5 m and less in size.
Silting A failure generally associated with a valve which movements are restricted due to small particles that have wedged in between critical clearances (e.g., the spool and bore.)
Single-pass Test Filter performance tests in which contaminant which passes through a test filter is not allowed to recirculate back to the test filter.
Sintered Medium A metallic or nonmetallic filter medium processed to cause diffusion bonds at all contacting points.
Sleeve Bearing A journal bearing, usually a full journal bearing.
Sloughing Off The release of contaminant from the upstream side of a filter element to the upstream side of the filter enclosure.
Sludge Insoluble material formed as a result either of deterioration reactions in an oil or of contamination of an oil, or both.
Solid Any substance having a definite shape which it does not readily relinquish. More generally, any substance in which the force required to produce a deformation depends upon the magnitude of the deformation rather than upon the rate of deformation.
Solvency Ability of a fluid to dissolve inorganic materials and polymers, which is a function of aromaticity.
Solvent A material with a strong capability to dissolve a given substance. The most common petroleum solvents are mineral spirits, xylene, toluene, hexane, heptane, and naphthas. Aromatic-type solvents have the highest solvency for organic chemical materials, followed by naphthenes and paraffins. In most applications, the solvent disappears, usually by evaporation, after it has served its purpose. The evaporation rate of a solvent is very important in manufacture.
Solvent Extraction A refining process used to separate components (unsaturated hydrocarbons) from lube distillates in order to improve the oils oxidation stability, viscosity index, and response to additives. The oil and the solvent extraction media are mixed in an extraction tower, resulting in the formation of two phases: a heavy phase consisting of the undesirable unsaturates dissolved in the solvent. And a lighter phase consisting of a high quality oil with some solvent dissolved in it. The phases are separated and the solvent recovered from each by distillation.
Specific Gravity The ratio of the weight of a given volume of material to the weight of an equal volume of water.
Specific Gravity (liquid) The ratio of the weight of a given volume of liquid to the weight of an equal volume of water.
Spectrographic Analysis Determines the concentration of elements represented in the entrained fluid contaminant.
Spectrographic Oil Analysis Program (SOAP) Procedures for extracting fluid samples from operating systems and analyzing them spectrographically for the presence of key elements.
Spindle Oil A light-bodied oil used principally for lubricating textile spindles and for light, high-speed machinery.
Spin-on Filter A throw-away type bowl and element assembly that mates with a permanently installed head.
Splash lubrication A system of lubrication in which parts of a mechanism dip into and splash the lubricant onto themselves and/or other parts of the mechanism.
Spur Gear This is the simplest variation of gear. It consists of a cylinder or disk, with the teeth projecting radially. Each tooth edge is straight and aligned parallel to the axis of rotation. Such gears can be meshed together correctly only if they are fitted to parallel axles.
SSU Saybolt Universal Seconds (or SUS), a unit of measure used to indicate viscosity, e.g., SSU @ 100 F
Static Friction The force just sufficient to initiate relative motion between two bodies under load. The value of the static friction at the instant relative motion begins is termed break-away friction.
Static Seal A seal between two surfaces which have no relative motion.
Stationary Seal A mechanical seal in which the flexible members do not rotate with the shaft.
Statistical Process Control (SPC) The use of control charts to track and eliminate variables in repetitive manufacturing processes, in order to ensure that the product is of consistent and predictable quality. If a chart reveals only chance variations that are inherent in the system, the process is said to be in a state of statistical control. If the chart reveals variations traceable to changes in equipment, procedures or workers, the process is said to be out of control. Statistical process control differs from statistical quality control in that the former monitors manufacturing process parameters and the latter monitors product quality parameters.
Steam Turbine A mechanical device that extracts thermal energy from pressurized steam. The energy is converted into a rotary motion that drives a device.
Stick-slip Motion Erratic, noisy motion characteristic of some machine ways, due to the starting friction encountered by a machine part at each end of its back-and-form (reciprocating) movement. This undesirable effect can be overcome with a way lubricant, which reduces starting friction.
STLE Society of Tribologist and Lubrication Engineers, formerly ASLE, American Society of Lubrication Engineers.
Stoke (St) Kinematic measurement of a fluid's resistance to flow defined by the ratio of the fluid's dynamic viscosity to its density.
Straight Mineral Oil Petroleum oil containing no additives. Straight mineral oils include such diverse products as low-cost once-through lubricants and thoroughly refined white oils. Most high-quality lubricants, however, contain additives.
Straight oil A mineral oil containing no additives.
Strainer A coarse filter element (pore size over approximately 40 m)
Suction Filter A pump intake-line filter in which the fluid is below atmospheric pressure.
Sulfated Ash The ash content of fresh, compounded lubricating oil as determined by ASTM Method D 874. Indicates level of metallic additives in the oil.
Sulfonate A hydrocarbon in which a hydrogen atom has been replaced with the highly polar (SO2OX) group, where X is a metallic ion or alkyl radical. Petroleum sulfonates are refinery by-products of the sulfuric acid treatment of white oils. Sulfonates have important applications as emulsifiers and chemical intermediates in petrochemical manufacture, and substituted sulfonates are widely used as corrosion inhibitors. Synthetic sulfonates can be manufactured from special feedstocks rather than from white oil base stocks.
Sulfur A common natural constituent of petroleum products. While certain sulfur compounds are commonly used to improve the EP, or load-carrying, properties of an oil, high sulfur content in a petroleum product may be undesirable as it can be corrosive and create an environmental hazard when burned. For these reasons, sulfur limitations are specified in the quality control of fuels, solvents, etc.
Sulfurized Oil Oil to which sulfur or sulfur compounds have been added.
Superclean 10 particles >10 micron per milliliter - Surface Fatigue Wear The formation of surface or subsurface cracks and fatigue crack propagation. It results from cyclic loading of a surface.
Surface Fatigue Wear The formation of surface or subsurface cracks and fatigue crack propagation. It results from cyclic loading of a surface.
Surface Filter Media Porous materials which primarily retain contaminants on the influent face, performing the actual process of filtration.
Surface Filtration Filtration which primarily retains contaminant on the influent surface.
Surface Tension The contractile surface force of a liquid by which it tends to assume a spherical form and to present the least possible surface. It is expressed in dynes/cm or ergs/cm2.
Surfactant Surface-active agent that reduces interfacial tension of a liquid. A surfactant used in a petroleum oil may increase the oil's affinity for metals and other materials.
Surge A momentary rise of pressure in a circuit.
SUS (SSU) Saybolt Universal Seconds. A measure of lubricating oil viscosity in the oil industry. The measuring apparatus is filled with specific quantity of oil or other Fluid and its flow time through standatized offrice is measured in Seconds. Fast flowing fluids (low viscosity) will have low value; Slow flowing fluids (high viscosity) will have high value.
Swarf The cuttings, and grinding fines that result from metal working operations.
Synthetic Hydrocarbon Oil molecule with superior oxidation quality tailored primarily out of paraffinic materials.
Synthetic Lubricant A lubricant produced by chemical synthesis rather than by extraction or refinement of petroleum to produce a compound with planned and predictable properties.
Synthetic Oils Oils produced by synthesis (chemical reaction) rather than by extraction or refinement. Many (but not all) synthetic oils offer immense advantages in terms of high temperature stability and low temperature fluidity, but are more costly than mineral oils. Major advantage of all synthetic oils is their chemical uniformity.
System Pressure The pressure which overcomes the total resistances in a system. It includes all losses as well as useful work.
T - T Temperature change, Fahrenheit
T Temperature change, Fahrenheit - Tacky A descriptive term applied to lubricating oils and greases which appear particularly sticky or adhesive.
Tacky A descriptive term applied to lubricating oils and greases which appear particularly sticky or adhesive.
TAN (Total) acid number - TBN (Total) base number
TBN (Total) base number - Thermal Conductivity Measure of the ability of a solid or liquid to transfer heat.
Thermal Conductivity Measure of the ability of a solid or liquid to transfer heat.
Thermal Stability Ability of a fuel or lubricant to resist oxidation under high temperature operating conditions.
Thermography The use of infrared thermography whereby temperatures of a wide variety of targets can be measured remotely and without contact. This is accomplished by measuring the infrared energy radiating from the surface of the target and converting this measurement to an equivalent surface temperature.
Thin Film Lubrication A condition of lubrication in which the film thickness of the lubricant is such that the friction between the surfaces is determined by the properties of the surfaces as well as by the viscosity of the lubricant.
Thixotropy That property of a lubricating grease which is manifested by a softening in consistency as a result of shearing followed by a hardening in consistency starting immediately after the shearing is stopped.
Three-body Abrasion A particulate wear process by which particles are pressed between two sliding surfaces.
Thrust Bearing An axial-load bearing. - Timken EP Test Measure of the extreme-pressure properties of a lubricating oil. The test utilizes a Timken machine, which consists of a stationary block pushed upward, by means of a lever arm system, against the rotating outer race of a roller bearing, which is lubricated by the product under test. The test continues under increasing load (pressure) until a measurable wear scar is formed on the block.
Timken EP Test Measure of the extreme-pressure properties of a lubricating oil. The test utilizes a Timken machine, which consists of a stationary block pushed upward, by means of a lever arm system, against the rotating outer race of a roller bearing, which is lubricated by the product under test. The test continues under increasing load (pressure) until a measurable wear scar is formed on the block.
Timken OK Load The heaviest load that a test lubricant will sustain without scoring the test block in the Timken Test procedures, ASTM Methods D 2509 (greases) and D 2782 (oils).
Total Acid Number (TAN) The quantity of base, expressed in milligrams of potassium hydroxide, that is required to neutralize all acidic constituents present in 1 gram of sample. (ASTM Designation D 974.) See Acid Number.
Total Base Number (TBN) The quantity of acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide that is required to neutralize all basic constituents present in 1 gram of sample. (ASTM Designation D 974.) See Base Number.
Tribology The science and technology of interacting surfaces in relative motion, including the study of lubrication, friction and wear. Tribological wear is wear that occurs as a result of relative motion at the surface.
Turbidity The degree of opacity of a fluid.
Turbine Oil A top-quality rust- and oxidation-inhibited (R&O) oil that meets the rigid requirements traditionally imposed on steam-turbine lubrication. Quality turbine oils are also distinguished by good demulsibility, a requisite of effective oil-water separation. Turbine oils are widely used in other exacting applications for which long service life and dependable lubrication are mandatory. Such compressors, hydraulic systems, gear drives, and other equipment. Turbine oils can also be used as heat transfer fluids in open systems, where oxidation stability is of primary importance.
Turbulent Flow A flow situation in which the fluid particles move in a random manner.
Turbulent Flow Flow in which the velocity at any point varies on an erratic basic. It occurs when flow velocity exceeds a limiting value or when tube configuration irregularities preclude laminar flow.
Turbulent flow Sampler A sampler that contains a flow path in which turbulence is induced in the main stream by abruptly changing the direction of the fluid.
U - Ultraclean 1 particle >10 micron per milliliter
Ultraclean 1 particle >10 micron per milliliter - Unbalanced Seal A mechanical seal arrangement wherein the full hydraulic pressure of the seal chamber acts to close the seal faces.
Unbalanced Seal A mechanical seal arrangement wherein the full hydraulic pressure of the seal chamber acts to close the seal faces.
Unloading The release of contaminant that was initially captured by the filter medium.
V - V Total volume (gals)
V Total volume (gals) - Vacuum Dehydration A method which involves drying or freeing of moisture through a vacuum process.
Vacuum Dehydration A method which involves drying or freeing of moisture through a vacuum process.
Vacuum Distillation A distillation method which involved reducing the pressure above a liquid mixture to be distilled to less than its vapor pressure (usually less than atmospheric pressure). This causes evaporation of the most volatile liquid(s) - those with the lowest boiling points. This method works on the principle that boiling occurs when a liquid's vapor pressure exceeds the ambient pressure. It can be used with or without heating the solution.
Vacuum Pump A device that is used to extract gas or vapor from an enclosed space, leaving behind a partial vacuum in the container.
Vacuum Separator A separator that utilizes subatmospheric pressure to remove certain gases and liquids from another liquid because of their difference in vapor pressure.
Valve A device which controls fluid flow direction, pressure, or flow rate.
Valve Lifter Sometimes called a "cam follower," a component in engine designs that use a linkage system between a cam and the valve it operates. The lifter typically translates the rotational motion of the cam to a reciprocating linear motion in the linkage system.
Vapor Pressure Pressure of a confined vapor in equilibrium with its liquid at specified temperature thus, a measure of a liquid's volatility.
Vapor Pressure-Reid (RVP) Measure of the pressure of vapor accumulated above a sample of gasoline or other volatile fuel in a standard bomb at 100F (37.8C). Used to predict the vapor locking tendencies of the fuel in a vehicle's fuel system. Controlled by law in some areas to limit air pollution from hydrocarbon evaporation while dispensing.
Variable Displacement Pump A pump in which the displacement per cycle can be varied.
Varnish When applied to lubrication, a thin, insoluble, nonwipeable film deposit occurring on interior parts, resulting from the oxidation and polymerization of fuels and lubricants. Can cause sticking and malfunction of close-clearance moving parts. Similar to, but softer, than lacquer.
Viscometer or Viscosimeter An apparatus for determining the viscosity of a fluid.
Viscosity Measurement of a fluid's resistance to flow. The common metric unit of absolute viscosity is the poise, which is defined as the force in dynes required to move a surface one square centimeter in area past a parallel surface at a speed of one centimeter per second, with the surfaces separated by a fluid film one centimeter thick. In addition to kinematic viscosity, there are other methods for determining viscosity, including Saybolt Universal Viscosity (SUV), Saybolt Furol viscosity, Engier viscosity, and Redwood viscosity. Since viscosity varies in inversely with temperature, its value is meaningless until the temperature at which it is determined is reported.
Viscosity Grade Any of a number of systems which characterize lubricants according to viscosity for particular applications, such as industrial oils, gear oils, automotive engine oils, automotive gear oils, and aircraft piston engine oils.
Viscosity Index (VI) A commonly used measure of a fluid's change of viscosity with temperature. The higher the viscosity index, the smaller the relative change in viscosity with temperature.
Viscosity Index Improvers Additives that increase the viscosity of the fluid throughout its useful temperature range. Such additives are polymers that possess thickening power as a result of their high molecular weight and are necessary for formulation of multi-grade engine oils.
Viscosity Modifier Lubricant additive, usually a high molecular weight polymer, that reduces the tendency of an oil's viscosity to change with temperature.
Viscosity-temperature Relationship The manner in which the viscosity of a given fluid varies inversely with temperature. Because of the mathematical relationship that exists between these two variables, it is possible to predict graphically the viscosity of a petroleum fluid at any temperature within a limited range if the viscosities at two other temperatures are known. The charts used for this purpose are the ASTM Standard Viscosity-Temperature Charts for liquid Petroleum Products, available in 6 ranges. If two know viscosity-temperature points of a fluid are located on the chart and a straight line drawn through them, other viscosity-temperature values of the fluid will fall on this line; however, values near or below the cloud point of the oil may deviate from the straight-line relationship.
Viscous Possessing viscosity. Frequently used to imply high viscosity.
Volatility This property describes the degree and rate at which a liquid will vaporize under given conditions of temperature and pressure. When liquid stability changes, this property is often reduced in value.
W - Water-Glycol Fluid A fluid whose major constituents are water and one or more glycols or polyglycols.
Water-Glycol Fluid A fluid whose major constituents are water and one or more glycols or polyglycols.
Way Longitudinal surface that guides the reciprocal movement of a machine part.
Way Lubricant Lubricant for the sliding ways of machine tools such as planers, grinders, horizontal boring machines, shapers, jig borers, and milling machines. A good way lubricant is formulated with special frictional characteristics designed to overcome the stick-slip motion associated with slow-moving machine parts.
Wear The attrition or rubbing away of the surface of a material as a result of mechanical action.
Wear Debris Particles that are detached from machine surfaces as a result of wear and corrosion. Also known as wear particles.
Wear Inhibitor An additive which protects the rubbing surfaces against wear, particularly from scuffing, if the hydrodynamic film is ruptured.
Weld Point The lowest applied load in kilograms at which the rotating ball in the Four Ball EP test either seizes and welds to the three stationary balls, or at which extreme scoring of the three balls results
Wicking The vertical absorption of a liquid into a porous material by capillary forces.
Work Penetration The penetration of a sample of lubricating grease immediately after it has been brought to 77F and then subjected to 60 stokes in a standard grease worker. This procedure and the standard grease worker are described in ASTM Method D 217.
Worm Gear A gear that is in the form of a screw. The screw thread engages the teeth on a worm wheel. When rotated, the worm pulls or pushes the wheel, causing rotation.
Z - ZDDP An antiwear additive found in many types of hydraulic and lubricating fluids. Zinc dialkyldithiophosphate.
ZDDP An antiwear additive found in many types of hydraulic and lubricating fluids. Zinc dialkyldithiophosphate.
Roof Type Properties - Help
Help - Modify type properties to change a roof family's structure, fill pattern, and more.
Modify type properties to change a roof family's structure, fill pattern, and more.
To change type properties, select an element and click Modify tabProperties panel (Type Properties). Changes to type properties apply to all instances in the project.
Construction - Structure
Structure - Indicates the thickness of the roof type, which is determined by the cumulative thickness of its layers. This is a read-only property.
Indicates the thickness of the roof type, which is determined by the cumulative thickness of its layers. This is a read-only property.
Graphics - Coarse Scale Fill Pattern
Coarse Scale Fill Pattern - The fill pattern for a roof displayed at a coarse detail level.
The fill pattern for a roof displayed at a coarse detail level.
Coarse Scale Fill Color - Applies a color to the fill pattern for a roof in a coarse-scale view.
Applies a color to the fill pattern for a roof in a coarse-scale view.
Identity Data - Keynote
Keynote - Add or edit the roof keynote. Click in the value box to open the Keynotes dialog.
Add or edit the roof keynote. Click in the value box to open the Keynotes dialog.
Description of the assembly, based on the assembly code selection.
Assembly code - Uniformat assembly code selected from hierarchical list.
Uniformat assembly code selected from hierarchical list. - Type Mark
Type Mark - A value to designate the particular roof. This value must be unique for each roof in a project. Revit issues a warning if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.
A value to designate the particular roof. This value must be unique for each roof in a project. Revit issues a warning if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.
Cost - Cost of the roofing material. The cost can be included in a schedule.
Cost of the roofing material. The cost can be included in a schedule.
Analytical Properties - Heat Transfer Coefficient (U)
Heat Transfer Coefficient (U) - Used in calculating the heat transfer, typically by convection or phase change between a fluid and a solid.
Used in calculating the heat transfer, typically by convection or phase change between a fluid and a solid.
Thermal Resistance (R) - A measure of a temperature difference, by which an object, or material, resist a heat flow (heat per time unit or thermal resistance.
A measure of a temperature difference, by which an object, or material, resist a heat flow (heat per time unit or thermal resistance.
Thermal mass - Equivalent to thermal capacitance or heat capacity.
Equivalent to thermal capacitance or heat capacity. - Absorptance
Absorptance - A measure of the ability of an object to absorb radiation, equal to the ratio of the absorbed radiant flux to the incident flux.
A measure of the ability of an object to absorb radiation, equal to the ratio of the absorbed radiant flux to the incident flux.
How to Calculate a Wall's Surface Area - Things You'll Need
Things You'll Need - Calculator
Calculator - Pencil
Pencil - Paper
Paper - Tip
Tip - Sketch the surface area to be measured and record the measurements and results as you go. Simplify your math by rounding inches to feet unless absolutely necessary.
Sketch the surface area to be measured and record the measurements and results as you go. Simplify your math by rounding inches to feet unless absolutely necessary.
Because most walls are square or rectangular, you can determine their surface area by multiplying the width and height measurements and then subtracting any door or window space. Atypical architecture and design, however, can result in having triangular, circular or trapezoidal shapes combined with the rectangle. The key to calculating the surface area of a wall accurately is using the basic formulas for finding the area of two-dimensional shapes.
Advertisement - Rectangular Walls
Rectangular Walls - Step 1
Step 1 - Measure the vertical height and horizontal width of the wall.
Measure the vertical height and horizontal width of the wall.
Step 2 - Multiply width and height measurements.
Multiply width and height measurements. - Step 3
Step 3 - Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Walls with Triangular Shapes - Step 1
Step 1 - Calculate any rectangular area and write down the result.
Calculate any rectangular area and write down the result.
Advertisement - Step 2
Step 2 - Locate the triangular shape. Measure the width along its base and the height from the base to the highest point.
Locate the triangular shape. Measure the width along its base and the height from the base to the highest point.
Step 3 - Multiply the base and height measurements then divide the result by 2. Add this to the result you recorded in Step 1.
Multiply the base and height measurements then divide the result by 2. Add this to the result you recorded in Step 1.
Step 4 - Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Walls with Trapezoidal Shapes - Step 1
Step 1 - Calculate any rectangular area and write down the result.
Calculate any rectangular area and write down the result.
Advertisement - Step 2
Step 2 - Measure the width of the bottom, the width of the top and the height. Write these numbers down.
Measure the width of the bottom, the width of the top and the height. Write these numbers down.
Step 3 - Add the width measurements together and divide by 2. Multiply this number by the height measurement. Add this result to solution in Step 1.
Add the width measurements together and divide by 2. Multiply this number by the height measurement. Add this result to solution in Step 1.
Step 4 - Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Walls with Circular Shapes - Step 1
Step 1 - Calculate any rectangular area and write down the result.
Calculate any rectangular area and write down the result.
Advertisement - Step 2
Step 2 - Measure from the middle of the circle to the edge, which is known as the radius.
Measure from the middle of the circle to the edge, which is known as the radius.
Step 3 - Multiply the measurement of the radius by itself, which is also known as squaring.
Multiply the measurement of the radius by itself, which is also known as squaring.
Step 4 - Multiply the result of squaring the radius by 3.14.
Multiply the result of squaring the radius by 3.14.
Step 5 - Divide the result in step 4 by 2, because you most likely need the area of only a portion a circle. Add this result to the area that you calculated in Step 1.
Divide the result in step 4 by 2, because you most likely need the area of only a portion a circle. Add this result to the area that you calculated in Step 1.
Step 6 - Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Calculate the areas for doors and windows, if any. Subtract that amount from your overall measurements to determine the actual wall surface area.
Based in Austin, Texas, David Clarke is a multi-talented professional who began his writing career in 2010. His informative articles span a variety of topics and have been published on various websites and blogs. He holds a Bachelor of Arts in English from Texas State University.
Definition from ISO 6707-1:1989: Vertical construction usually in masonry or in concrete which bounds or subdivides a construction works and fulfils a load bearing or retaining function.
Definition from buildingSMART: The wall represents a vertical construction that bounds or subdivides spaces. Wall are usually vertical, or nearly vertical, planar elements, often designed to bear structural loads. A wall is however not required to be load bearing. The IFC specification provides two entities for wall occurrences:
IfcWallStandardCase used for all occurrences of walls, that have a non-changing thickness along the wall path and where the thickness parameter can be fully described by a material layer set. These walls are always represented geometrically by a SweptSolid geometry, if a 3D geometric representation is assigned,
IfcWall used for all other occurrences of wall, particularly for walls with changing thickness along the wall path (e.g. polygonal walls), or walls with a non-rectangular cross sections (e.g. L-shaped retaining walls).
HISTORY New entity in IFC Release 1.0, the entity has changed in IFC Release 2x.
Type Use Definition - IfcWall (or the subtype IfcWallStandardCase) defines the occuurence of any wall, common information about wall types (or styles) is handled by IfcWallType. The IfcWallType (if present) may establish the common type name, usage (or predefined) type, common material layer set, common set of properties and common shape representations (using IfcRepresentationMap). The IfcWallType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsDefinedBy attribute.
IfcWall (or the subtype IfcWallStandardCase) defines the occuurence of any wall, common information about wall types (or styles) is handled by IfcWallType. The IfcWallType (if present) may establish the common type name, usage (or predefined) type, common material layer set, common set of properties and common shape representations (using IfcRepresentationMap). The IfcWallType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsDefinedBy attribute.
Property Set Use Definition: - The property sets relating to the IfcWall are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to the IfcWall are part of this IFC release:
The property sets relating to the IfcWall are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to the IfcWall are part of this IFC release:
Pset_WallCommon: common property set for all wall occurrences
Quantity Use Definition: - The quantities relating to the IfcWall are defined by the IfcElementQuantity and attached by the IfcRelDefinesByProperties. The following quantities are foreseen, but will be subjected to the local standard of measurement:
The quantities relating to the IfcWall are defined by the IfcElementQuantity and attached by the IfcRelDefinesByProperties. The following quantities are foreseen, but will be subjected to the local standard of measurement:
Name - Description
Description - Value Type
Value Type - NominalLength
NominalLength - Total nominal (or average) length of the wall along the wall path. The exact definition and calculation rules depend on the method of measurement used.
Total nominal (or average) length of the wall along the wall path. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityLength - NominalWidth
NominalWidth - Total nominal (or average) width (or thickness) of the wall perpendicular to the wall path. The exact definition and calculation rules depend on the method of measurement used.
Total nominal (or average) width (or thickness) of the wall perpendicular to the wall path. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityLength - NominalHeight
NominalHeight - Total nominal (or average) height of the wall along the wall path. The exact definition and calculation rules depend on the method of measurement used.
Total nominal (or average) height of the wall along the wall path. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityLength - GrossFootprintArea
GrossFootprintArea - Area of the wall as viewed by a ground floor view, not taking any wall modifications (like recesses) into account. It is also referred to as the foot print of the wall. The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by a ground floor view, not taking any wall modifications (like recesses) into account. It is also referred to as the foot print of the wall. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - NetFootprintArea
NetFootprintArea - Area of the wall as viewed by a ground floor view, taking all wall modifications (like recesses) into account. It is also referred to as the foot print of the wall. The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by a ground floor view, taking all wall modifications (like recesses) into account. It is also referred to as the foot print of the wall. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - GrossSideAreaLeft
GrossSideAreaLeft - Area of the wall as viewed by an elevation view of the left side (when viewed along the wall path orientation). It does not take into account any wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by an elevation view of the left side (when viewed along the wall path orientation). It does not take into account any wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - NetSideAreaLeft
NetSideAreaLeft - Area of the wall as viewed by an elevation view of the left side (when viewed along the wall path orientation). It does take into account all wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by an elevation view of the left side (when viewed along the wall path orientation). It does take into account all wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - GrossSideAreaRight
GrossSideAreaRight - Area of the wall as viewed by an elevation view of the right side (when viewed along the wall path orientation). It does not take into account any wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by an elevation view of the right side (when viewed along the wall path orientation). It does not take into account any wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - NetSideAreaRight
NetSideAreaRight - Area of the wall as viewed by an elevation view of the right side (when viewed along the wall path orientation). It does take into account all wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
Area of the wall as viewed by an elevation view of the right side (when viewed along the wall path orientation). It does take into account all wall modifications (such as openings). The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityArea - GrossVolume
GrossVolume - Volume of the wall, without taking into account the openings and the connection geometry. The exact definition and calculation rules depend on the method of measurement used.
Volume of the wall, without taking into account the openings and the connection geometry. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityVolume - NetVolume
NetVolume - Volume of the wall, after subtracting the openings and after considering the connection geometry. The exact definition and calculation rules depend on the method of measurement used.
Volume of the wall, after subtracting the openings and after considering the connection geometry. The exact definition and calculation rules depend on the method of measurement used.
IfcQuantityVolume - Containment Use Definition
Containment Use Definition - The IfcWall (and the subtype IfcWallStandardCase) as any subtype of IfcBuildingElement, may participate in two different containment relationships. The first (and in most implementation scenarios mandatory) relationship is the hierachical spatial containment, the second (optional) relationship is the aggregation within an element assembly.
The IfcWall (and the subtype IfcWallStandardCase) as any subtype of IfcBuildingElement, may participate in two different containment relationships. The first (and in most implementation scenarios mandatory) relationship is the hierachical spatial containment, the second (optional) relationship is the aggregation within an element assembly.
The IfcWall is places within the project spatial hierarchy using the objectified relationship IfcRelContainedInSpatialStructure, refering to it by its inverse attribute SELF\IfcElement.ContainedInStructure. Subtypes of IfcSpatialStructureElement are valid spatial containers, with IfcBuildingStorey being the default container.
The IfcWall may be aggregated into an element assembly using the objectified relationship IfcRelAggregates, refering to it by its inverse attribute SELF\IfcObjectDefinition.Decomposes. Any subtype of IfcElement can be an element assembly, with IfcElementAssembly as a special focus subtype. In this case the wall should not be additionally contained in the project spatial hierarchy, i.e. SELF\IfcElement.ContainedInStructure should be NIL.
The IfcWall may also be an aggregate i.e. being composed by other elements and acting as an assembly using the objectified relationship IfcRelAggregates, refering to it by its inverse attribute SELF\IfcObjectDefinition.IsDecomposedBy. Components of a wall are described by instances of IfcBuildingElementPart that are aggregated to form a complex wall. In this case, the contained IfcBuildingElementPart's should not be additionally contained in the project spatial hierarchy, i.e. the inverse attribute SELF\IfcElement.ContainedInStructure of IfcBuildingElementPart should be NIL.
Geometry Use Definitions: - The geometric representation of IfcWall is given by the IfcProductDefinitionShape, allowing multiple geometric representation. Included are:
The geometric representation of IfcWall is given by the IfcProductDefinitionShape, allowing multiple geometric representation. Included are:
Local Placement - The local placement for IfcWall is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.
The local placement for IfcWall is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.
The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcSpatialStructureElement that is used in the ContainedInStructure inverse attribute or to a referenced spatial structure element at a higher level.
If the relative placement is not used, the absolute placement is defined within the world coordinate system.
Geometric Representations - Currently, the use of 'SweptSolid', 'Clipping', and 'Brep' representations is supported. In addition the general representation types 'SurfaceModel' and 'BoundingBox' are allowed. The geometry use definition for 'BoundingBox', 'SurfaceModel' and 'Brep' is explained at IfcBuildingElement. A more restricted geometry definition is given at the level of the subtype IfcWallStandardCase.
Currently, the use of 'SweptSolid', 'Clipping', and 'Brep' representations is supported. In addition the general representation types 'SurfaceModel' and 'BoundingBox' are allowed. The geometry use definition for 'BoundingBox', 'SurfaceModel' and 'Brep' is explained at IfcBuildingElement. A more restricted geometry definition is given at the level of the subtype IfcWallStandardCase.
SweptSolid representation - The standard geometric representation (for body) of IfcWall is defined using the 'SweptSolid' representation. It is based on the vertical extrusion of a polygonal footprint of the wall body. The IfcShapeRepresentation shall have the following values:
The standard geometric representation (for body) of IfcWall is defined using the 'SweptSolid' representation. It is based on the vertical extrusion of a polygonal footprint of the wall body. The IfcShapeRepresentation shall have the following values:
RepresentationIdentifier : 'Body' - RepresentationType : 'SweptSolid'
RepresentationType : 'SweptSolid' - The following additional constraints apply to the swept solid representation:
The following additional constraints apply to the swept solid representation:
Solid: IfcExtrudedAreaSolid is required, - Profile: IfcArbitraryClosedProfileDef shall be supported.
Profile: IfcArbitraryClosedProfileDef shall be supported. - Extrusion: The profile shall be extruded vertically, i.e., in the direction of the z-axis of the co-ordinate system of the referred spatial structure element. It might be further constraint to be in the direction of the global z-axis in implementers agreements. The extrusion axis shall be perpendicular to the swept profile, i.e. pointing into the direction of the z-axis of the Position of the IfcExtrudedAreaSolid.
Extrusion: The profile shall be extruded vertically, i.e., in the direction of the z-axis of the co-ordinate system of the referred spatial structure element. It might be further constraint to be in the direction of the global z-axis in implementers agreements. The extrusion axis shall be perpendicular to the swept profile, i.e. pointing into the direction of the z-axis of the Position of the IfcExtrudedAreaSolid.
Connection Geometry - The connection between two walls is represented by the IfcRelConnectsPathElements. The use of the parameter of that relationship object is defined at the level of the subtypes of IfcWall and at the IfcRelConnectsPathElements.
The connection between two walls is represented by the IfcRelConnectsPathElements. The use of the parameter of that relationship object is defined at the level of the subtypes of IfcWall and at the IfcRelConnectsPathElements.
Do They Use Mortar to Fill Gaps Around Windows?
By: Alexis Lawrence - 21 September, 2017
21 September, 2017 - Mortar has a variety of uses in building design, serving as the adhesive for numerous materials, including brick, concrete blocks and, in some instances, ceramic and porcelain tiles. Mortar also helps fill in the spaces between these building materials and can also be used to fill in gaps around some types of windows.
Mortar has a variety of uses in building design, serving as the adhesive for numerous materials, including brick, concrete blocks and, in some instances, ceramic and porcelain tiles. Mortar also helps fill in the spaces between these building materials and can also be used to fill in gaps around some types of windows.
Filling With Mortar - Gaps in masonry windows, such as windows with bricks or concrete frames, can be filled with mortar. If there is a slim crack, the mortar can be mixed up to a heavy paste and spread between the masonry blocks to fill it in. You can also find premixed mortar, known as leveling compound. Either mortar type can be applied to cracks with a putty knife.
Gaps in masonry windows, such as windows with bricks or concrete frames, can be filled with mortar. If there is a slim crack, the mortar can be mixed up to a heavy paste and spread between the masonry blocks to fill it in. You can also find premixed mortar, known as leveling compound. Either mortar type can be applied to cracks with a putty knife.
Mortar as an Adhesive - If the bricks or blocks around a window fall out of the window frame, mortar may be used as an adhesive to replace them. It should be mixed according to the directions on the packaging to create a thick, heavy adhesive and spread around the inside of each hole in the window frame. Then, a brick or block can be pressed into each space around the window. Once set up, it should dry the same color as the rest of the mortar used in the design. Ideally, you wont be able to tell that the blocks or bricks were ever missing.
If the bricks or blocks around a window fall out of the window frame, mortar may be used as an adhesive to replace them. It should be mixed according to the directions on the packaging to create a thick, heavy adhesive and spread around the inside of each hole in the window frame. Then, a brick or block can be pressed into each space around the window. Once set up, it should dry the same color as the rest of the mortar used in the design. Ideally, you wont be able to tell that the blocks or bricks were ever missing.
Gaps in masonry windows, such as windows with bricks or concrete frames, can be filled with mortar.
If there is a slim crack, the mortar can be mixed up to a heavy paste and spread between the masonry blocks to fill it in.
Other Windows - The gaps around most other types of window frames, such as wood or metal, should not be filled in with mortar. Though mortar works as an adhesive substance, the material is porous and does allow both air and moisture to pass through. Gaps in the edges of wood or metal windows should be filled in with caulk, which prevents air from getting through and also provides water-resistance. If the holes in the window frame are in the actual wood frame, you can also use wood filler, which works much in the same way that mortar does to fill in a crack.
The gaps around most other types of window frames, such as wood or metal, should not be filled in with mortar. Though mortar works as an adhesive substance, the material is porous and does allow both air and moisture to pass through. Gaps in the edges of wood or metal windows should be filled in with caulk, which prevents air from getting through and also provides water-resistance. If the holes in the window frame are in the actual wood frame, you can also use wood filler, which works much in the same way that mortar does to fill in a crack.
Alternatives to Mortar - For small cracks that appear in concrete and other masonry windows, you dont have to necessarily use mortar to fill in the gaps. Grout is one alternative to mortar. Both of these materials have the same basic installation process, which is an application with either a putty knife or grout float that can be time-consuming. If the cracks are small, you can also use silicone caulk, which has a simpler installation process, just as you would on a wood or metal window.
For small cracks that appear in concrete and other masonry windows, you dont have to necessarily use mortar to fill in the gaps. Grout is one alternative to mortar. Both of these materials have the same basic installation process, which is an application with either a putty knife or grout float that can be time-consuming. If the cracks are small, you can also use silicone caulk, which has a simpler installation process, just as you would on a wood or metal window.
The gaps around most other types of window frames, such as wood or metal, should not be filled in with mortar.
If the cracks are small, you can also use silicone caulk, which has a simpler installation process, just as you would on a wood or metal window.
Alexis Lawrence is a freelance writer, filmmaker and photographer with extensive experience in digital video, book publishing and graphic design. An avid traveler, Lawrence has visited at least 10 cities on each inhabitable continent. She has attended several universities and holds a Bachelor of Science in English.
This information pape - er is one of a serries of papers wrritten during the preparation of the book Whaat Colour is You
er is one of a serries of papers wrritten during the preparation of the book Whaat Colour is You
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ourbuilding.com - m). The papers d o not form part of the book and
m). The papers d o not form part of the book and
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d. They provide - furtherr technical detail, analysis and information
furtherr technical detail, analysis and information - i
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to ssupport stateme - ents made in the book. All of thhe papers can be
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m. - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Ventilation rates in offices mechanical and natural - This information paper provides an overview of the rates used in various standards for mechanical
This information paper provides an overview of the rates used in various standards for mechanical
and natural ventilation. - 1.
1. - AIR QUALITY AND FRESH (OUTDOOR) AIR RATES
AIR QUALITY AND FRESH (OUTDOOR) AIR RATES
Table 1 summarises the drivers behind the minimum fresh (outside) air requirements in office
buildings. - Issue
Issue - Fresh Air Requirement
Fresh Air Requirement - Odours
Odours - Research shows that an occupants perception of indoor air quality is strongly influenced by odour.1 This
Research shows that an occupants perception of indoor air quality is strongly influenced by odour.1 This
can be controlled by introducing fresh air and/or treating recirculated air. Toilet exhausts are an example
of removing odours at source without recirculation. - CO2
CO2 - CO2 concentrations are often used as a surrogate indicator for odours inside buildings, with a limit of
CO2 concentrations are often used as a surrogate indicator for odours inside buildings, with a limit of
between 1,000 to 1,500 ppm typically adopted,2 (compared to 450 ppm currently found in outside air).
This typically requires between 7.5 to 10 l/s/person of outside air to achieve. Prolonged CO2 levels above
1,500 ppm may cause occupants to feel drowsy, get headaches, or function at lower activity levels.
Indoor pollutants - These include volatile organic compounds (VOC) and formaldehyde (off-gassing from carpets, paint and
These include volatile organic compounds (VOC) and formaldehyde (off-gassing from carpets, paint and
furniture), ozone (from photocopiers), carbon monoxide, radon, sulphur dioxide, and a host of other
substances. The best approach is to avoid introducing pollutants in the first place by selecting low offgassing materials and to exhaust sources of pollution locally (e.g. direct exhaust of photocopy rooms).
Cigarette smoke - Smoking indoors was a major source of indoor pollutant and has been banned in many countries. A
Smoking indoors was a major source of indoor pollutant and has been banned in many countries. A
ventilation rate of at least 30 l/s/person is typically required if smoking is permitted.3
Oxygen to - breathe
breathe - To meet the human bodys demand for oxygen when seated typically requires less than 0.2 l/s/person of
To meet the human bodys demand for oxygen when seated typically requires less than 0.2 l/s/person of
fresh air.4 This is clearly not a driver for minimum ventilation rates in buildings.
Table 1 Summary of fresh air requirements in office buildings
The minimum fresh air requirement of 8 to 10 l/s per person typically adopted in mechanically
ventilated spaces is supported by a variety of sources (refer to section 2). Fresh air requirements
for naturally ventilated spaces are treated differently (refer to section 3).
British Standard BS EN 13779 provides four classifications of indoor air quality as shown in
Table 2. - www.wholecarbonfootprint.com
www.wholecarbonfootprint.com - 2
2 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Classification - Indoor air
Indoor air - quality standard
quality standard - Fresh air
Fresh air - ventilation range
ventilation range - (L/s/p)
(L/s/p) - Fresh air default
Fresh air default - value (L/s/p)
value (L/s/p) - Approximate indoor
Approximate indoor - CO2 concentration
CO2 concentration - (ppm) *
(ppm) * - IDA1
IDA1 - High
High - >15
>15 - 20
20 - 700 to 750
700 to 750 - IDA2
IDA2 - Medium
Medium - 1015
1015 - 12.5
12.5 - 850 to 900
850 to 900 - IDA3
IDA3 - Moderate
Moderate - 610
610 - 8
8 - 1,150 to 1,200
1,150 to 1,200 - IDA4
IDA4 - Low
Low - <6
<6 - 5
5 - 1,550 to 1,600
1,550 to 1,600 - * taken from Table 4.2, CIBSE Guide A, including CO2 concentration rise plus external CO2
* taken from Table 4.2, CIBSE Guide A, including CO2 concentration rise plus external CO2
Table 2 Indoor air quality classifications in BS EN 13779
2. - MINIMUM FRESH (OUTDOOR) AIR VENTILATION RATES
MINIMUM FRESH (OUTDOOR) AIR VENTILATION RATES - Table 3 provides a summary of various regulations, standards and guidelines related to minimum
Table 3 provides a summary of various regulations, standards and guidelines related to minimum
fresh (outdoor) air rates. - Source
Source - l/s per
l/s per - person
person - Comments
Comments - Part F, UK Building
Part F, UK Building - Regulations 2010
Regulations 2010 - 10
10 - Total outdoor air supply rate with no smoking and no significant pollution sources.
Total outdoor air supply rate with no smoking and no significant pollution sources.
Extract rates are also given: - Printers / Photocopier rooms 20 l/s per machine
Printers / Photocopier rooms 20 l/s per machine
WC/Urinal 6 l/s each - Shower 15 l/s each
Shower 15 l/s each - CIBSE Guide A, Table 1.5
CIBSE Guide A, Table 1.5 - 10
10 - Applies to executive, general and open plan offices. Assumes no smoking.
Applies to executive, general and open plan offices. Assumes no smoking.
CIBSE Guide A, section - 8.4.1.2
8.4.1.2 - 8
8 - As a general rule, the fresh air supply rate should not fall below between 5 and 8 l/s per
As a general rule, the fresh air supply rate should not fall below between 5 and 8 l/s per
occupant but this will depend on various other factors including floor area per occupant,
processes carried out, equipment used and whether the work is strenuous. For office
workers, 8 l/s fresh air is roughly equivalent to an elevation of 600 ppm of carbon dioxide
(CO2) which, when added to the normal outdoor CO2 of 400 ppm, gives an internal CO2
concentration of 1,000 ppm; 5 l/s would be equivalent to 1,350 ppm internally. The
higher ventilation rate of 8 l/s per person is recommended.
Note: Schools have prescribed ventilation rates of 3 l/s per person for background ventilation
and 8 L/s per person when required.
12 to 16 - Suggests an allowance of 1.2 to1.6 l/s per m2, which based on a standard occupancy of 1
Suggests an allowance of 1.2 to1.6 l/s per m2, which based on a standard occupancy of 1
person per 10m2 equates to 12 to16 l/s/person. For an occupancy of 1 per 6 m2 this
equates to 7 to 10 l/s/person.
ASHRAE Handbook: - Fundamentals 2009,
Fundamentals 2009, - chapter 16.10
chapter 16.10 - 10
10 - Engineering experience and field studies indicate that an outdoor air supply of about 10
Engineering experience and field studies indicate that an outdoor air supply of about 10
l/s per person is very likely to provide acceptable perceived indoor air quality in office
spaces, whereas lower rates may lead to increased sick building syndrome symptoms.
ASHRAE Technical FAQ ID - 34
34 - www.ashrae.org
www.ashrae.org - accessed 16 June 2012.
accessed 16 June 2012. - 7.5
7.5 - At the activity levels found in typical office buildings, steady-state CO2 concentrations of
At the activity levels found in typical office buildings, steady-state CO2 concentrations of
about 700 ppm above outdoor air levels indicate an outdoor air ventilation rate of about
7.5 l/s/person. Laboratory and field studies have shown that this rate of ventilation will
dilute odours from human bio-effluents to levels that will satisfy a substantial majority
(about 80%) of un-adapted persons (visitors) in a space.
BCO Guide to - Specification 2009
Specification 2009 - www.wholecarbonfootprint.com
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3 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Source - l/s per
l/s per - person
person - ASHRAE Standard 62.12007
ASHRAE Standard 62.12007 - 8.5
8.5 - Comments
Comments - The fresh air required is based on both the number of occupants, the area of the space
The fresh air required is based on both the number of occupants, the area of the space
and the effectiveness of the ventilation system to deliver the fresh air to the breathing
zone (refer Section H4.12 in Appendix H). For a typical office the calculation is:
Fresh air (l/s) = - (2.5 l/s x no. of people) + (0.3 x floor area)
(2.5 l/s x no. of people) + (0.3 x floor area)
Ventilation effectiveness factor - The default occupancy of 1 per 20 m2 gives 8.5 l/s/person (0.36 l/s/m2) and is used when
The default occupancy of 1 per 20 m2 gives 8.5 l/s/person (0.36 l/s/m2) and is used when
the actual occupancy is not known. An occupancy of 1 per 10 m2 gives 5.5 l/s/person
(0.55 l/s/m2). As occupancy density increases the amount of fresh air per person reduces.
BB101 Ventilation in - Schools
Schools - AS1668.2-1991 (Australia)
AS1668.2-1991 (Australia) - 3 to 10
3 to 10 - When measured at seated head height, during the continuous period between the start
When measured at seated head height, during the continuous period between the start
and finish of teaching on any day, the average concentration of CO2 should not exceed
1,500ppm. In addition, the maximum concentration should not exceed 5,000 ppm
during the teaching day and at any occupied time, including teaching, the occupants
should be able to lower the concentration to 1,000 ppm.
Purpose-provided ventilation should provide external air supply to all teaching and
learning spaces of a minimum of 3 l/s per person and a minimum daily average of 5 l/s
per person. The capability of achieving a minimum of 8 l/s per person, under the control
of the occupant, at any time must also be provided, which should lower CO2 levels below
1,000ppm. - 10 l/s/person is defined for office accommodation in schools.
10 l/s/person is defined for office accommodation in schools.
7.5 - The minimum outdoor airflow rate for dilution of gaseous contaminants (e.g. body
The minimum outdoor airflow rate for dilution of gaseous contaminants (e.g. body
odours) is 7.5 l/s/person if the temperature in the enclosed space is below 27C in normal
use, and 15 l/s/person if it rises above 27C in normal use.
Table 3 Minimum fresh (outside) air rates from various sources
3. - MINIMUM NATURAL VENTILATION REQUIREMENTS
MINIMUM NATURAL VENTILATION REQUIREMENTS - A typical rule of thumb for natural ventilation is to provide an effective ventilation area equivalent
A typical rule of thumb for natural ventilation is to provide an effective ventilation area equivalent
to 5% of the floor area served refer to Section H4.2 in Appendix H. The 5% minimum
ventilation area requirement in Part F (Ventilation) of the UK Building Regulations was replaced
in 2006 with reference to Natural ventilation in non-domestic buildings, CIBSE Applications
Manual AM10. This manual provides detailed guidance on natural ventilation design and analysis,
taking into account both stack and wind effects. No simple percentages are given for opening
areas. BREEAM 2011 allows the 5% rule of thumb to be used as an alternative to using AM10.
FREE AND EFFECTIVE VENTILATION AREAS - Free area and effective ventilation area are not the same. Free area is the physical size of the opening.
Free area and effective ventilation area are not the same. Free area is the physical size of the opening.
Effective area is determined in a test facility based on the resistance to airflow through the opening.
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4 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Example calculation to test the rule of thumb for 5% natural ventilation area
The design formulae in CIBSE Guide A and CIBSE Guide AM10 have been used to test a 15 m
wide floor plate with 5% ventilation openings distributed evenly on opposite facades and at high
and low levels refer to Figure 1. - Fig 1
Fig 1 - Example building zone with cross ventilation and 5% ventilation openings
Example building zone with cross ventilation and 5% ventilation openings
To keep CO2 levels to less than an average 1,000 ppm during the day a ventilation rate of
10 l/s/person is typically adopted. This is equivalent to an air change per hour (ach) of 1.2 in this
example (= 10 l/s x 15 people x 3.6 / 450 m3). The AM10 Design Tool v55 was used to calculate the
CO2 concentrations based on this, and also the concentrations if only 3 l/s/person (0.36 ach) were
provided using trickle ventilators in the window frames.
Fig 2 - CO2 concentration (ppm) for 10 l/s/person (left) and 3 l/s/person (right) from CIBSE AM10 Design Tool v5
CO2 concentration (ppm) for 10 l/s/person (left) and 3 l/s/person (right) from CIBSE AM10 Design Tool v5
Relying only on trickle ventilation could lead to unacceptable CO2 concentrations when the
space is fully occupied. Opening the windows in winter could cause draughts and will increase
heating energy consumption. However, in a mechanical system 10 l/s/person of fresh air would be
provided and this also needs to be heated (and there is also additional energy consumption due to
the fans). Consequently, if the mechanical system doesnt have heat recovery then natural
ventilation should potentially have the lowest energy consumption if controlled properly.
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5 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
However, if the mechanical system has heat recovery (to preheat the fresh air supply) then this is
likely to be the most energy efficient solution, provided the fan energy consumption does not
outweigh the heating energy savings. This is the PassivHaus approach to ventilation in winter.
Air speed and natural ventilation areas for minimum fresh air
If fresh air enters through two windows on opposite facades then the air speed through an
opening can be crudely estimated as: - Air speed (m/s) = air flow (m3/s) / ventilation area (m2)
Air speed (m/s) = air flow (m3/s) / ventilation area (m2)
An air supply of 10 l/s/person is equivalent to 0.15 m3/s. An air speed of 0.15 m/s inside
buildings is generally considered to be imperceptible and not draughty. If the air speed is limited
to 0.15 m/s then the minimum ventilation area required is 1 m3 (or 0.7% of floor area). This
illustrates that the 5% rule of thumb is based on providing sufficient ventilation to remove heat
gains in summer and not to provide minimum fresh air during winter (which can often be
achieved using trickle ventilators). - Natural ventilation driving force wind versus temperature
Natural ventilation driving force wind versus temperature - The formulae in Table 4.22 of CIBSE Guide A can be used to estimate the airflow rates for simple
The formulae in Table 4.22 of CIBSE Guide A can be used to estimate the airflow rates for simple
building layouts, with openings on opposite sides, based on wind driven and stack driven
(temperature difference) effects. The assumptions made to calculate these for the building in
Figure 1 are shown in Table 4 - Wind
Wind - Wind speed (imperceptible)
Wind speed (imperceptible) - Temperature
Temperature - 1.5 m/s
1.5 m/s - External temperature
External temperature - 25C
25C - Pressure coeff 90 front
Pressure coeff 90 front - 0.2
0.2 - Internal temperature
Internal temperature - 28C
28C - Pressure coeff 90 rear
Pressure coeff 90 rear - -0.25
-0.25 - Difference
Difference - 3C
3C - Pressure coeff 45 front
Pressure coeff 45 front - 0.05
0.05 - Pressure coeff 45 front
Pressure coeff 45 front - -0.35
-0.35 - Table 4 Assumptions made to calculate wind and temperature driven natural ventilation
Table 4 Assumptions made to calculate wind and temperature driven natural ventilation
A coefficient of discharge (Cd) of 0.61 is adopted based on cl 4.6.1 of CIBSE Guide A to take
into account the pressure drop through a sharp edged opening, such as a window. The resulting
air flow rates are shown in Table 5.
www.wholecarbonfootprint.com - 6
6 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Wind @ - 90
90 - Wind @
Wind @ - 45
45 - Stack
Stack - effect
effect - Airflow rate (m3/s)
Airflow rate (m3/s) - 1.61
1.61 - 1.42
1.42 - 0.84
0.84 - Air changes per hour (ach)
Air changes per hour (ach) - 12.8
12.8 - 11.3
11.3 - 6.7
6.7 - l/s/person
l/s/person - 107
107 - 94
94 - 56
56 - Table 5 Natural ventilation air flow rates using formula in CIBSE Guide A
Table 5 Natural ventilation air flow rates using formula in CIBSE Guide A
The wind speed at which wind driven ventilation dominates compared to the stack effect
(with a temperature difference of 3C) is around 0.8 m/s. On all but the stillest days, wind is likely
to be the driving ventilation force. Figure 3 shows plots of air changes per hour for different wind
speeds and temperature differences in the example building in Figure 1.
14 - 14
14 - ach - 90
ach - 90 - ach - 45
ach - 45 - 12
12 - air changes per hour
air changes per hour - air changes per hour
air changes per hour - 12
12 - 10
10 - 8
8 - 6
6 - 10
10 - 8
8 - 6
6 - 4
4 - 4
4 - 2
2 - 2
2 - 0
0 - 0
0 - 0
0 - 0.25
0.25 - 0.5
0.5 - 0.75
0.75 - 1
1 - 1.25
1.25 - 1.5
1.5 - 0
0 - 1
1 - 2
2 - External wind speed (m/s)
External wind speed (m/s) - Fig 3
Fig 3 - 3
3 - 4
4 - 5
5 - 6
6 - Temperature difference C
Temperature difference C - Air changes per hour in example building for different wind speeds and T
Air changes per hour in example building for different wind speeds and T
Cooling benefit of natural ventilation - The ability of natural ventilation to remove heat depends on the ventilation rate and the
The ability of natural ventilation to remove heat depends on the ventilation rate and the
temperature difference between outside and inside. The equations are:
Heat extracted = - 1.2 x q x dT
1.2 x q x dT - OR
OR - (N x V / 3) x dT
(N x V / 3) x dT
where: - dT = difference in internal & external temperature
dT = difference in internal & external temperature - q = ventilation rate (l/s)
q = ventilation rate (l/s)
N = no. of air changes per hour
V = volume of space - Table 6 shows the cooling effects of the three options in Table 5 assuming a 3C temperature
Table 6 shows the cooling effects of the three options in Table 5 assuming a 3C temperature
differential. - www.wholecarbonfootprint.com
www.wholecarbonfootprint.com - 7
7 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Air changes per hour - 2
2 - Cooling (W/m )
Cooling (W/m ) - Wind @
Wind @ - 90
90 - Wind @
Wind @ - 45
45 - Stack
Stack - effect
effect - 12.8
12.8 - 11.3
11.3 - 6.7
6.7 - 39
39 - 34
34 - 20
20 - Table 6 Cooling effect due to wind and stack effect with T = 3C
Table 6 Cooling effect due to wind and stack effect with T = 3C
Figure 4 shows the cooling capacity (W/m2) for different air change rates and temperature
differences for a space with a ceiling height of 3 m calculated using the formula above.
70 - 1 ACH
1 ACH - Sensible cooling capacity (W/m2)
Sensible cooling capacity (W/m2) - 60
60 - 5 ACH
5 ACH - 10 ACH
10 ACH - 50
50 - 15 ACH
15 ACH - 40
40 - 30
30 - 20
20 - 10
10 - 0
0 - 0
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
5 - 6
6 - Temperature Difference C
Temperature Difference C - Fig 4
Fig 4 - Effect of temperature difference and air change rate on sensible cooling capacity of ventilation air
Effect of temperature difference and air change rate on sensible cooling capacity of ventilation air
(height of space = 3m) - www.wholecarbonfootprint.com
www.wholecarbonfootprint.com - 8
8 - Information Paper 20: Ventilation rates in offices mechanical and natural
Information Paper 20: Ventilation rates in offices mechanical and natural
Notes - All websites were accessed on 29 July 2013 unless noted otherwise.
All websites were accessed on 29 July 2013 unless noted otherwise.
1. - History of the Changing Concepts In Ventilation Requirements by Klauss et al, ASHRAE Journal, June 1970
History of the Changing Concepts In Ventilation Requirements by Klauss et al, ASHRAE Journal, June 1970
2. - Adapted from guidelines from CIBSE and ASHRAE.
Adapted from guidelines from CIBSE and ASHRAE. - 3.
3. - CIBSE Guide A recommends a minimum fresh air rate of 45 l/s/person. The 1999 version of the guide, before smoking
CIBSE Guide A recommends a minimum fresh air rate of 45 l/s/person. The 1999 version of the guide, before smoking
was banned in buildings in the UK, gave different ventilation rates based on the proportion of occupants smoking:
0% = 8 l/s, 25% = 16 l/s, 50% = 24 l/s, 75% = 36 l/s.
4. - The amount of air breathed by an adult when seated is less than 10 litres per minute (0.17 l/s). This increases to 58 litres
The amount of air breathed by an adult when seated is less than 10 litres per minute (0.17 l/s). This increases to 58 litres
(1 l/s) for an adult male running at 5 mph. Source: How Much Air Do We Breathe? California Environmental
Protection Agency,Research Note 94-11, August 1994. www.arb.ca.gov/research/resnotes/notes/94-11.htm
5. - CIBSE AM10 Design Tool v5 can be downloaded from www.cibse.org/docs/AM10CalcToolv5.xls.
CIBSE AM10 Design Tool v5 can be downloaded from www.cibse.org/docs/AM10CalcToolv5.xls.
The inevitable legal bit - While reasonable efforts have been made to provide accurate information, Cundall Johnston & Partners LLP do not make any
While reasonable efforts have been made to provide accurate information, Cundall Johnston & Partners LLP do not make any
representation, express or implied, with regard to the accuracy of information contained in this paper, nor do they accept any
legal responsibility or liability for any errors or omissions that may be made. This paper is provided for information purposes
only. Readers are encouraged to go to the source material to explore the issues further. Please feel free to use any material
(except photos, illustrations and data credited to other organisations) for educational purposes only under the Creative
Commons Attribution-Non-Commercial-Share-Alike 2.0 England & Wales licence. If you spot any errors in the paper then please
contact the author so that the paper can be corrected.
www.wholecarbonfootprint.com - 9
9 - A jamb (from French jambe, "leg"),[1] in architecture, is the side-post or lining of a doorway or other aperture. The jambs of a window outside the frame are called reveals. Small shafts to doors and windows with caps and bases are known as jamb-shafts; when in the inside arris of the jamb of a window they are sometimes called "scoinsons."
A jamb (from French jambe, "leg"),[1] in architecture, is the side-post or lining of a doorway or other aperture. The jambs of a window outside the frame are called reveals. Small shafts to doors and windows with caps and bases are known as jamb-shafts; when in the inside arris of the jamb of a window they are sometimes called "scoinsons."
A doorjamb, door jamb (also sometimes doorpost) is the vertical portion of the door frame onto which a door is secured.[2] The jamb bears the weight of the door through its hinges, and most types of door latches and deadbolts extend into a recess in the doorjamb when engaged, making the accuracy of the plumb (i.e. true vertical) and strength of the doorjambs vitally important to the overall operational durability and security of the door.
The word jamb is also used to describe a wing of a building, perhaps just in Scottish architecture. John Adam added a 'jamb' to the old Leith Customs house in the Citadel of Leith in 17541755.[3]
^ Edinburgh City Archives. Dean of Guild Court papers, warrant granted to John Adam on 27 June 1764 when he presented a full set of building accounts.
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We have a range of single leaf folding doors to suit smaller openings, available in oak or white finishes with glazed or solid panels.
Climadoor brand internal bifold doors give you peace of mind for quality and ease of fitment.
We offer a wide range of External Hardwood and Malaysian Oak Door frames to Suit standard sized doors.
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A great range of high quality, sturdy Single colour and Dual colour handle packs to add the finishing touch to your internal door.
Available in a range of styles, sizes and finishes, we have standard skirting packs, which will add the finishing touches to any home interior design.
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A wide range of traditional and modern internal door architrave sets in various options and styles.
Traditional internal French doors are perfect for making your home's layout feel open and flowing. They're ideal for areas of the house that you want to let the light filter through.
Folding French doors are internal door systems that combine both the benefits of traditional french doors and bifold doors. These uniquely designed doors have a central opening access, but also have sidelights that can be folded right back against th
The Door Dictionary: Door Terminology Explained - In whatever field you find yourself stumbling into in life, there will undoubtedly be a fair amount of jargon to decode before you can truly understand whats going on. Jargon is the lingo we use in order to make ourselves feel like experts, when in actuality, all it does is distance us from one another. Even so, when it comes to doors, especially wooden doors, there is a serious amount of jargon to wade through, some of which is quite self-explanatory, but much of which is surprisingly convoluted. Here, well be guiding you through a dictionary of door-related words that you might find cropping up whilst youre conducting your door buying research. This is far from an intensive list, but it should help you get a head start at least!
In whatever field you find yourself stumbling into in life, there will undoubtedly be a fair amount of jargon to decode before you can truly understand whats going on. Jargon is the lingo we use in order to make ourselves feel like experts, when in actuality, all it does is distance us from one another. Even so, when it comes to doors, especially wooden doors, there is a serious amount of jargon to wade through, some of which is quite self-explanatory, but much of which is surprisingly convoluted. Here, well be guiding you through a dictionary of door-related words that you might find cropping up whilst youre conducting your door buying research. This is far from an intensive list, but it should help you get a head start at least!
Door Terminology Defined - A
A - Aperture The actual opening in which youll be installing your door.
Aperture The actual opening in which youll be installing your door.
Architrave This refers to the door frame. Why the industry cant just refer to it as a frame is honestly beyond us. The word has its origins in classic architecture, where it referred to a main beam that rests across the tops of a number of columns. The frame includes the head, sill and jambs.
B - Backset This is a measurement of the horizontal distance from the front of the door lock to the centre of the keyhole and is generally measured from the centre of the lock edge for a bevelled front and from the lower section of the lock for a rabbeted front. This will obviously vary greatly depending on the specific design of the door.
Backset This is a measurement of the horizontal distance from the front of the door lock to the centre of the keyhole and is generally measured from the centre of the lock edge for a bevelled front and from the lower section of the lock for a rabbeted front. This will obviously vary greatly depending on the specific design of the door.
Bifold Door A bifold door is a door that, as the name suggests, folds in on itself in order to make the most of a space. Bifold doors can be used either externally, for example as patio or conservatory doors, or internally to protect wardrobes or pantries, or to segregate rooms. They are generally more desirable than patio of French doors, and are perceived as being more modern, reliable and aesthetically pleasing.
Bore A bored lock is a tubular or cylindrical lock that requires a bored opening. The bore refers to this opening. Bore holes will typically be single or double.
C - Casing This is largely decorative, and refers to the panelling that covers the gap where the door frame (or architrave) meets the wall. The casing will generally be one of the most aesthetically pleasing parts of your door, and as such will require a fair amount of maintenance.
Casing This is largely decorative, and refers to the panelling that covers the gap where the door frame (or architrave) meets the wall. The casing will generally be one of the most aesthetically pleasing parts of your door, and as such will require a fair amount of maintenance.
D - Door Set The door set acts as the barrier that protects one room from another. They do, however, serve other functions such as adding to the fire resistance of your door, and acting as an extra barrier against sound.
Door Set The door set acts as the barrier that protects one room from another. They do, however, serve other functions such as adding to the fire resistance of your door, and acting as an extra barrier against sound.
E - Engineered Door This is a door constructed to not only be more stable and reliable than a conventional door, but to be more environmentally friendly too due to an improved timber yield. Engineered doors have a different internal structure to generic, solid construction door, which is typically made up of separate, one-piece components that are then fixed together. Engineered doors, however, are made from multiple layers of timber, which are pressed and fixed together in different directions to form the core material. A veneer is often also applied to the surface. They have significant performance benefits when compared to solid doors, but might not appear as aesthetically pleasing to some people. Its all a matter of preference really.
Engineered Door This is a door constructed to not only be more stable and reliable than a conventional door, but to be more environmentally friendly too due to an improved timber yield. Engineered doors have a different internal structure to generic, solid construction door, which is typically made up of separate, one-piece components that are then fixed together. Engineered doors, however, are made from multiple layers of timber, which are pressed and fixed together in different directions to form the core material. A veneer is often also applied to the surface. They have significant performance benefits when compared to solid doors, but might not appear as aesthetically pleasing to some people. Its all a matter of preference really.
F - French Door A potential alternative to a bifold door, a French door will be a typically a wooden or plastic door with glass panels surrounded by narrow stiles. Youll commonly find them leading out to patios or gardens and they are often double-glazed. You will find them available in either in swinging or out swinging styles.
French Door A potential alternative to a bifold door, a French door will be a typically a wooden or plastic door with glass panels surrounded by narrow stiles. Youll commonly find them leading out to patios or gardens and they are often double-glazed. You will find them available in either in swinging or out swinging styles.
G - Glazing This refers simply to glass installed in windows and doors. Single glazing means there is a single pane of glass installed, whereas double glazing or insulating glass has two panes of glass separated with dead air between them. This creates better insulation and noise reduction, not to mention security, but can result in condensation build-up.
Glazing This refers simply to glass installed in windows and doors. Single glazing means there is a single pane of glass installed, whereas double glazing or insulating glass has two panes of glass separated with dead air between them. This creates better insulation and noise reduction, not to mention security, but can result in condensation build-up.
H - Hardwood This is wood formed from strong, broad-leaved trees, which are generally of much higher density and surface hardness than softwood tress, making them more desirable for external applications.
Hardwood This is wood formed from strong, broad-leaved trees, which are generally of much higher density and surface hardness than softwood tress, making them more desirable for external applications.
Hinge The hinges are the plates and pins used to attach the panels to the door frame, and are engineered to allow the doors to swing either outward on inward.
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J - Jamb This is simply the vertical part of the frame. You can get numerous types of jamb, including a strike jamb, where youll attach the strike, and the hinge jamb, on which youll attach the hinges. Oh and its pronounced Jam, as in the confectionary. The b is silent!
Jamb This is simply the vertical part of the frame. You can get numerous types of jamb, including a strike jamb, where youll attach the strike, and the hinge jamb, on which youll attach the hinges. Oh and its pronounced Jam, as in the confectionary. The b is silent!
L - Laminate Laminating refers to the method of gluing strips of thin, clear wood to the core in order to act as a sort of protective skin thats generally thicker than a veneer and more durable as a result.
Laminate Laminating refers to the method of gluing strips of thin, clear wood to the core in order to act as a sort of protective skin thats generally thicker than a veneer and more durable as a result.
Lead Door As the name suggests, the lead door is not made out of lead, but is the door the door handle is attached to that leads the other doors. Youll generally only find lead doors when youre dealing with bifolding doors or sliding doors.
Leaf The most common type of door, a leaf is technically any door featuring a single panel that fills a doorway. Chances are that most of the doors in your home are single leaf.
Lintel This is the top section of the doorway and is also otherwise known as the head or the top jamb. Often made of concrete, steel or stone, this structural, horizontal block will be supported by two vertical supports and can be a load-bearing structural component, a decorative element, or both.
Lipping The lipping creates the edge of the door and can be reduced slightly in size to fit a specific opening without exposing the inner core of the door.
Lockset This simply refers to the overall locking mechanism, including the handle if it has one.
M - Mortise Lock This is a lock that sits inside a slot cut into the door, as opposed to a lock that sits on the external portion of the door. Mortise locks are generally more secure.
Mortise Lock This is a lock that sits inside a slot cut into the door, as opposed to a lock that sits on the external portion of the door. Mortise locks are generally more secure.
O - Opening The actual opening of the doorframe where your door will be hung measured from the floor to the head rabbet vertically and between the jambs vertically. The opening size will be slightly larger than the door itself as it will need to also include room for clearance.
Opening The actual opening of the doorframe where your door will be hung measured from the floor to the head rabbet vertically and between the jambs vertically. The opening size will be slightly larger than the door itself as it will need to also include room for clearance.
Overhang The amount the roof over the door extends past the wall.
P - Panel Every door will be made up of panels that will either be wood, plastic or glass.
Panel Every door will be made up of panels that will either be wood, plastic or glass.
Prefinished If your door has already been painted or varnished before its been hung then it is referred to as prefinished.
Prehung In much the same manner as above, a prehung door will already be attached as a fully functioning unit, which can be installed into the aperture (door opening) without any further assembly.
S - Sidelight These are panels that sit at the side of the door and are generally decorative. They could be installed with glass in order to let more light into your home.
Sidelight These are panels that sit at the side of the door and are generally decorative. They could be installed with glass in order to let more light into your home.
Slave Door The door or doors that follows the lead door (see lead door).
Softwood This wood is derived from conifer trees such as pine trees and is generally more aesthetically pleasing than hardwood, but less durable. As such, youll generally only find softwood door indoors.
Strikeplate The plate found on the inside of the doors that protect the jamb from the locking mechanism.
T - Threshold This is the bottom section of the door and will typically be made of a more durable material such as aluminium. Many thresholds, especially external thresholds, will be extended with a matching piece that slides into the outer edge of the existing threshold.
Threshold This is the bottom section of the door and will typically be made of a more durable material such as aluminium. Many thresholds, especially external thresholds, will be extended with a matching piece that slides into the outer edge of the existing threshold.
Top Hung Again, this is rather self-explanatory, as a top hung door is literally a door that is hung from above or a rail. Many bifold doors and sliding doors will be top hung.
Track The track will be found in bifold and sliding doors, and is the often metal tracking that the doors themselves slot into. The track is called as such because is resembles a train track.
U - Unfinished A door that has yet to be varnished and/or painted.
Unfinished A door that has yet to be varnished and/or painted.
U-Value This is a grade that measures how eco-friendly your door is. The higher your U-Value, the better insulation and energy efficiency youll get from your door.
V - Veneer A thin slice of decorative timber placed on the visible face of your door that exists primarily for aesthetic reasons, but will add a slight amount of extra protection. Generally used on internal doors.
Veneer A thin slice of decorative timber placed on the visible face of your door that exists primarily for aesthetic reasons, but will add a slight amount of extra protection. Generally used on internal doors.
Vents Added to certain doors to allow for controlled ventilation.
Weatherboard A resilient material added in order to seal the door from the elements, protecting from water and air infiltration.
As weve already mentioned, this is far from an exhaustive glossary, but there is more than enough here to get you started, and help you to read the average instruction manual without breaking out a confused sweat. Good luck! And remember, the internet is always there is you ever get stuck. To cut down on any needless fiddling around though, we recommend printing out a copy of this very glossary and keeping it on your person at all times if youre considering installing your own wooden door.
E-Echocardiograhy will go offline June 30th, 2022. CME is Offline Jan 14th, 2022
Acoustic Windows - Help>Acoustic Windows>1
Help>Acoustic Windows>1 - Introduction
Introduction - An acoustic window is the location from which an ultrasound probe makes it's scan. The probe can be turned and/or angled in different directions yielding a different view, but all of the views are from the same acoustic window or perspective. The acoustic windows, in echocardiography, are divided by the scan type, transthoracic or transesophageal.
An acoustic window is the location from which an ultrasound probe makes it's scan. The probe can be turned and/or angled in different directions yielding a different view, but all of the views are from the same acoustic window or perspective. The acoustic windows, in echocardiography, are divided by the scan type, transthoracic or transesophageal.
Transesophageal Windows - The acoustic windows in a transesophageal scan are:
The acoustic windows in a transesophageal scan are:
This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education through the joint providership of University of Nebraska Medical Center, Center for Continuing Education and JLS Interactive, LLC.
The University of Nebraska Medical Center, Center for Continuing Education is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.
This activity is approved by the American Society of Radiologic Technologists (ASRT) as sonography-related continuing education (CE). Credit(s) issued for successful completion of ASRT-approved CE activities are accepted by the American Registry of Diagnostic Medical Sonography, American Registry of Radiological Technologists, Cardiovascular Credentialing International and Canadian Association of Registered Diagnostic Ultrasound Professionals. Contact the applicable registry for additional information / restrictions on their acceptance of ASRT CE credit.
Name Type Description - ConstructionMethod P_SINGLEVALUE / IfcLabel
ConstructionMethod P_SINGLEVALUE / IfcLabel - Construction Method Designator for whether the concrete element is constructed on site or prefabricated. Allowed values are: 'In-Situ' vs 'Precast'.
Construction Method Designator for whether the concrete element is constructed on site or prefabricated. Allowed values are: 'In-Situ' vs 'Precast'.
StructuralClass P_SINGLEVALUE / IfcLabel - Structural Class The structural class defined for the concrete structure (e.g. '1').
Structural Class The structural class defined for the concrete structure (e.g. '1').
StrengthClass P_SINGLEVALUE / IfcLabel - Strength Class Classification of the concrete strength in accordance with the concrete design code which is applied in the project.
Strength Class Classification of the concrete strength in accordance with the concrete design code which is applied in the project.
ExposureClass P_SINGLEVALUE / IfcLabel - Exposure Class Classification of exposure to environmental conditions, usually specified in accordance with the concrete design code which is applied in the project.
Exposure Class Classification of exposure to environmental conditions, usually specified in accordance with the concrete design code which is applied in the project.
ReinforcementVolumeRatio P_SINGLEVALUE / IfcMassDensityMeasure - Reinforcement Volume Ratio The required ratio of the effective mass of the reinforcement to the effective volume of the concrete of a reinforced concrete structural element.
Reinforcement Volume Ratio The required ratio of the effective mass of the reinforcement to the effective volume of the concrete of a reinforced concrete structural element.
ReinforcementAreaRatio P_SINGLEVALUE / IfcAreaDensityMeasure - Reinforcement Area Ratio The required ratio of the effective area of the reinforcement to the effective area of the concrete At any section of a reinforced concrete structural element.
Reinforcement Area Ratio The required ratio of the effective area of the reinforcement to the effective area of the concrete At any section of a reinforced concrete structural element.
DimensionalAccuracyClass P_SINGLEVALUE / IfcLabel - Dimensional Accuracy Class Classification designation of the dimensional accuracy requirement according to local standards.
Dimensional Accuracy Class Classification designation of the dimensional accuracy requirement according to local standards.
ConstructionToleranceClass P_SINGLEVALUE / IfcLabel - Construction Tolerance Class Classification designation of the on-site construction tolerances according to local standards.
Construction Tolerance Class Classification designation of the on-site construction tolerances according to local standards.
ConcreteCover P_SINGLEVALUE / IfcPositiveLengthMeasure - Concrete Cover The protective concrete cover at the reinforcing bars according to local building regulations.
Concrete Cover The protective concrete cover at the reinforcing bars according to local building regulations.
ConcreteCoverAtMainBars P_SINGLEVALUE / IfcPositiveLengthMeasure - Concrete Cover At Main Bars The protective concrete cover at the main reinforcing bars according to local building regulations.
Concrete Cover At Main Bars The protective concrete cover at the main reinforcing bars according to local building regulations.
ConcreteCoverAtLinks P_SINGLEVALUE / IfcPositiveLengthMeasure - Concrete Cover At Links The protective concrete cover at the reinforcement links according to local building regulations.
Concrete Cover At Links The protective concrete cover at the reinforcement links according to local building regulations.
ReinforcementStrengthClass P_SINGLEVALUE / IfcLabel - Reinforcement Strength Class Classification of the reinforcement strength in accordance with the concrete design code which is applied in the project. The reinforcing strength class often combines strength and ductility.
Reinforcement Strength Class Classification of the reinforcement strength in accordance with the concrete design code which is applied in the project. The reinforcing strength class often combines strength and ductility.
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Room Criteria - RC - measuring background noise in a building over frequencies ranging 16 Hz to 4000 Hz
Sponsored Links - Room Criteria (RC) measures the background noise in buildings over frequencies ranging 16 Hz to 4000 Hz.
Room Criteria (RC) measures the background noise in buildings over frequencies ranging 16 Hz to 4000 Hz.
RC requires a determination of the mid-frequency average level and the perceived balance between high and low frequency sound.
1) Neutral (N). The levels in the octave bands centered at 500 Hz and below must not exceed the octave-band levels of the reference spectrum by more than 5 dB at any point in the range; the levels in the octave bands centered at 1000 Hz and above must not exceed the octave-band level of the reference spectrum by more than 3 dB at any point in the range.
Sponsored Links - Related Topics
Related Topics - Acoustics - Room acoustics and acoustic properties - decibel A, B and C - Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation
Acoustics - Room acoustics and acoustic properties - decibel A, B and C - Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation
Related Documents - NC - Noise Criterion - Noise Criterion - NC - level is a standard describing relative loudness of a space with a range of frequencies
NC - Noise Criterion - Noise Criterion - NC - level is a standard describing relative loudness of a space with a range of frequencies
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Advertise in the ToolBox - Citation
Citation - This page can be cited as
This page can be cited as - Engineering ToolBox, (2004). RC - Room Criteria. [online] Available at: https://www.engineeringtoolbox.com/rc-room-criteria-d_729.html [Accessed Day Mo. Year].
Engineering ToolBox, (2004). RC - Room Criteria. [online] Available at: https://www.engineeringtoolbox.com/rc-room-criteria-d_729.html [Accessed Day Mo. Year].
Renovation - "Renovators" redirects here. For the Australian TV game show, see The Renovators.
"Renovators" redirects here. For the Australian TV game show, see The Renovators.
Truman's renovation of the White House, 17 May 1950
Renovations (also called remodeling) is the process of improving a broken, damaged, or outdated structure. Renovations are typically either commercial or residential.[citation needed] Additionally, renovation can refer to making something new, or bringing something back to life and can apply in social contexts. For example, a community can be renovated if it is strengthened and revived.
Contents - The interior of a Victorian building in Lincoln Park, Chicago in the process of being renovated in June 1971. Note the elements of the edifice scattered and sorted about.
The interior of a Victorian building in Lincoln Park, Chicago in the process of being renovated in June 1971. Note the elements of the edifice scattered and sorted about.
Technology has had a meaningful impact on the renovation process, increasing the significance and strength of the planning stage. The availability of free online design tools has improved visualization of the changes, at a fraction of the cost of hiring a professional interior designer. The decision regarding changes is also influenced by the purpose of renovation. In case of a so-called "fix-and-flip" (repair and resell) objective, an ROI (return on investment) can result from changes to fix a structural issue or design flow yield[1] or to use light and color to make rooms appear more spacious.
Many people renovate homes to create a new appearance for their home, or so another person can live in the residence.[2] Builders often renovate homes because it is a stable source of income.[3] Homeowners often renovate their homes to increase the re-sale value and to turn a profit when selling.[4]
Wood is versatile and flexible, making it the easiest construction material for renovations, and wood buildings can be redesigned to suit changing needs. Few homeowners or professional remodellers possess the skill and equipment that is required to alter steel-frame or concrete structures.
Forest certification verifies that wood products have been sourced from well-managed forests. Most certification programs provide online search options so that consumers can find certified productsthe Certification Canada program includes a search option for all of the certification programs that are in use in Canada.[5]
In North America, most structures are demolished because of external forces such as zoning changes and rising land values. Additionally, buildings that cannot be modified to serve the functional needs of the occupants are subject to demolition. Very few buildings on the continent are demolished due to structural degradation.[6]
The Athena Institute surveyed 227 commercial and residential buildings that were demolished in St. Paul, Minnesota, between 2000 and mid-2003. Thirty percent of the buildings were less than 50 years old, and 6% were less than 25 years old. The four top reasons for demolition were area redevelopment (35%), buildings physical condition (31%), not suitable for anticipated use (22%), and fire damage (7%). Lack of maintenance was cited as the specific problem for 54 of the 70 buildings where physical condition was given as the reason for demolition.[6]
Most builders focus on building new homes, so renovating is typically a part-time activity for such tradespeople. The processes and services required for renovations are quite specific and, once plans are signed off, building a new home is relatively predictable. Renovations usually require all of the sub-trades that are needed for the construction of a new building. During renovation projects, flexibility is often required from renovation companies to respond to unexpected issues that arise. Projects involving renovation require not just flexibility, but a plan that had been agreed upon by multiple parties. The planning process will involve feedback from financial investors of the project, and from the designer. Part of planning will also entail the collection of data for the completion of the project and then the project plan will be revised and given consent before continuing with renovations.[7]
^ Harvey, C. (2012). Renovate or sell? Builders, homeowners opt for remodeling investment. Business Journal Serving Fresno & The Central San Joaquin Valley, 1-5.
Renovation Windows - Up to 35% of your home's heat loss can be attributed to old wood or old aluminum windows. New Modern Energy Star vinyl windows are the perfect replacement window for your home. Modern Windows can quickly and easily convert and renovate old wood or aluminum windows into brand new vinyl windows.
Up to 35% of your home's heat loss can be attributed to old wood or old aluminum windows. New Modern Energy Star vinyl windows are the perfect replacement window for your home. Modern Windows can quickly and easily convert and renovate old wood or aluminum windows into brand new vinyl windows.
Renovation Windows - With literally thousands of vinyl window renovation projects under our belt, our experienced sales team can answer any questions you have about window styles, pricing, and energy efficiency. Our professional window installers go out of their way to ensure your upgrade to energy efficient windows is worry free with as little disruption to you and your family as possible.
With literally thousands of vinyl window renovation projects under our belt, our experienced sales team can answer any questions you have about window styles, pricing, and energy efficiency. Our professional window installers go out of their way to ensure your upgrade to energy efficient windows is worry free with as little disruption to you and your family as possible.
In addition to providing a cost effective solution for your window renovations, we also offer a multitude of opening styles (casement, awnings and sliders) and 2 installation methods to best suit your needs.
Before and After - Vinyl Renovation Windows into Wood Windows: Process
Vinyl Renovation Windows into Wood Windows: Process - Rebate Windows vs Nail-on Windows for Aluminum Window Replacement
Rebate Windows vs Nail-on Windows for Aluminum Window Replacement
If youre replacing your old wood windows or aluminum windows with vinyl windows, there are two window installation methods to choose from: a renovation window OR a full cut-out using a nail on window.
Installation using a Renovation Window - The installation of a renovation window (also known as a rebate window or rebate flange window) allows you to upgrade your older homes wood or aluminum windows without having to cut into the building envelope (siding and/or wall). This installation method sees the glass and inner structure of your current windows removed but leaves the perimeter of your existing window frame intact. The new windows are inserted over top of this existing frame (also known as piggybacking) and then secured into place. Insulation is then added around the window and trim is added so that there are no visible traces of the old window.
The installation of a renovation window (also known as a rebate window or rebate flange window) allows you to upgrade your older homes wood or aluminum windows without having to cut into the building envelope (siding and/or wall). This installation method sees the glass and inner structure of your current windows removed but leaves the perimeter of your existing window frame intact. The new windows are inserted over top of this existing frame (also known as piggybacking) and then secured into place. Insulation is then added around the window and trim is added so that there are no visible traces of the old window.
75% of window renovations use a renovation window, as there are some significant benefits:
1. Less Expensive: Approximately half the cost of replacing an old window with a new Energy Star window is associated with tearing the old window out. Using a renovation window method does not require the perimeter of the old frame to be removed and therefore saves on both labour and material costs. 2. Less Invasive: As a renovation window installation does not require the cutting or tearing out of the entire old window frame, your building envelope (siding and wall construction) is not touched or compromised. It avoids cuts to your building sheathing that expose the buildings siding and possible leakage points, making renovation windows a worthwhile consideration 3. Avoids Stucco Siding: Stucco is a hazardous material and requires careful and proper protection of the installers, you and your family, and to your home. The time and effort it takes to prevent possible harm (protective gear, extra time, disposal, etc) adds additional costs to a job. The installation of renovation windows avoids the need to handle or cut into stucco, saving significant amounts of time and labour costs. 4. Reduces Installation Time: Time is not only money, its also convenience. At Modern, we strive to cause you the least amount of inconvenience while working in your home. Our goal is to complete your window installation as quickly as possible without compromising quality. Rebate windows typically take half the time to install as a nail on window.
Installation Using a Nail on Window: - Nail-on refers to the actual installation method of this kind of window. Nail on windows use a nailing fin allowing the window, through this fin, to be affixed to the framing on the building. In order to retrofit a new nail-on window into an older home the original nail-on windows need to be completely removed. This is accomplished by removing the exterior trim, and often includes cutting back siding in order to expose the original nailing fin. The nails holding the original window in place are removed, old window completely removed and then the rough opening (hole where window was) is prepared for the new windows installation. The new window is situated, nailed into place and any additional sealing and insulation is applied as necessary. The siding and/or trim is put back in place and your new window is installed.
Nail-on refers to the actual installation method of this kind of window. Nail on windows use a nailing fin allowing the window, through this fin, to be affixed to the framing on the building. In order to retrofit a new nail-on window into an older home the original nail-on windows need to be completely removed. This is accomplished by removing the exterior trim, and often includes cutting back siding in order to expose the original nailing fin. The nails holding the original window in place are removed, old window completely removed and then the rough opening (hole where window was) is prepared for the new windows installation. The new window is situated, nailed into place and any additional sealing and insulation is applied as necessary. The siding and/or trim is put back in place and your new window is installed.
The structure, energy ratings, and quality of a nail-on window versus a renovation window are identical. The defining difference between the two is related to the installation method and the use of a nailing fin or a flange. Our Exterior Specialists would be happy to go over the merits of both installation methods during your estimate consult and provide you with a quote for both options for your consideration.
Vinyl or Aluminum Window Replacement Looking for a renovation and remodeling contractor in Nanaimo, Duncan, Port Alberni, Courtenay, Parksville, Campbell River, Powell River or the Sunshine Coast? Modern can help. Please see the individual product pages for more information on renovating your home's exterior.
Room temperature - Mercury-in-glass thermometer showing an ambient temperature within the range of room temperature
Mercury-in-glass thermometer showing an ambient temperature within the range of room temperature
Colloquially, room temperature is the range of air temperatures that most people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing. Human comfort can extend beyond this range depending on humidity, air circulation and other factors. In certain fields, like science and engineering, and within a particular context, room temperature can mean different agreed-on ranges. In contrast, ambient temperature is the actual temperature of the air (or other medium and surroundings) in any particular place, as measured by a thermometer. It may be very different from usual room temperature, for example an unheated room in winter.
Owing to variations in humidity and likely clothing, recommendations for summer and winter may vary; a suggested typical range for summer is 2325.5 C (7378 F), with that for winter being 2023.5 C (6874 F).[3] Studies from Nigeria show a comfortable temperature range of 2628 C (7982 F), comfortably cool 2426 C (7579 F) and comfortably warm 2830 C (8286 F).[4]
Some studies have suggested that thermal comfort preferences of men and women may differ significantly, with women on average preferring higher ambient temperatures.[5][6][7]
The World Health Organization in 1987 found that comfortable indoor temperatures between 1824 C (6475 F) were not associated with health risks for healthy adults with appropriate clothing, humidity, and other factors. For infants, the very elderly, and those with significant health problems, a minimum 20 C (68 F) was recommended. Temperatures lower than 16 C (61 F) with humidity above 65% were associated with respiratory hazards including allergies.[8][9]
The WHO's 2018 guidelines give a strong recommendation that a minimum of 18 C (64 F) is a "safe and well-balanced indoor temperature to protect the health of general populations during cold seasons", while a higher minimum may be necessary for vulnerable groups including children, the elderly, and people with cardiorespiratory disease and other chronic illnesses. The recommendation regarding risk of exposure to high indoor temperatures is only "conditional". Minimal-risk high temperatures range from about 2130 C (7086 F) depending on the region, with maximum acceptable temperatures between 2532 C (7790 F).[10]
A high room temperature can cause either heat exhaustion or heat stroke in a person, in this case, a room temperature of 36.4C (97F) in an unventilated room during a heat wave.
Temperature ranges are defined as room temperature for certain products and processes in industry, science, and consumer goods. For instance, for the shipping and storage of pharmaceuticals, the United States Pharmacopeia-National Formulary (USP-NF) defines controlled room temperature as between 20 to 25 C (68 to 77 F), with excursions between 15 to 30 C (59 to 86 F) allowed, provided the mean kinetic temperature does not exceed 25 C (77 F).[11] The European Pharmacopoeia defines it as being simply 15 to 25 C (59 to 77 F), and the Japanese Pharmacopeia defines "ordinary temperature" as 15 to 25 C (59 to 77 F), with room temperature being 1 to 30 C (34 to 86 F).[12][13] Merriam-Webster gives as a medical definition a range of 15 to 25 C (59 to 77 F) as being suitable for human occupancy, and at which laboratory experiments are usually performed.[14]
^ Komolafe, L. Kayode; Akingbade, Folorunso O. A. (2003). "Analysis of thermal comfort in Lagos, Nigeria". Global Journal of Environmental Sciences: 5965. Retrieved 4 March 2021. Cite journal requires (help)
^ Beshir, MY; Ramsey, JD (March 1981). "Comparison between male and female subjective estimates of thermal effects and sensations". Applied Ergonomics. 12 (1): 2933. doi:10.1016/0003-6870(81)90091-0. PMID 15676395.
^ Karjalainen, Sami (April 2007). "Gender differences in thermal comfort and use of thermostats in everyday thermal environments". Building and Environment. 42 (4): 15941603. doi:10.1016/j.buildenv.2006.01.009.
^ Kingma, Boris; van Marken Lichtenbelt, Wouter (August 2015). "Energy consumption in buildings and female thermal demand". Nature Climate Change. 5 (12): 10541056. Bibcode:2015NatCC...5.1054K. doi:10.1038/nclimate2741.
^ Shein-Chung Chow (2007). Statistical Design and Analysis of Stability Studies. Chapman & Hall/CRC Biostatistics Series. CRC Press. p. 7. ISBN 9781584889069. Retrieved 4 April 2018. 1.2.3.3 Definition of Room Temperature: According to the United States Pharmacopeia National Forumlary [sic] (USP-NF), the definition of room temperature is between 15 and 30 C in the United States. However, in the EU, the room temperature is defined as being 15 to 25 C, while in Japan, it is defined being 1 to 30 C.
Service life - This article is about the manufacturing concept. For the economic concept of service life, see Fixed capital.
This article is about the manufacturing concept. For the economic concept of service life, see Fixed capital.
A product's service life is its period of use in service. It is mostly used in a non-technical context and has no scientific support or meaning. Several other terms more accurately describe a product's life, from the point of manufacture, storage, and distribution, and eventual use.
Service life has been defined as "a product's total life in use from the point of sale to the point of discard" and distinguished from replacement life,"the period after which the initial purchaser returns to the shop for a replacement".[1] Determining a product's expected service life as part of business policy involves using tools and calculations from maintainability and reliability analysis. Service life represents a commitment made by the item's manufacturer and is usually specified as a median. It is the time that any manufactured item can be expected to be "serviceable" or supported by its manufacturer.[citation needed]
Service life is not to be confused with shelf life, which deals with storage time, or with technical life, which is the maximum period during which it can physically function.[1] It also differs from predicted life, or MTTF/MTBF (Mean Time to Failure/Mean Time Between Failures)/MFOP (maintenance-free operating period). Predicted life is useful such that a manufacturer may estimate, by hypothetical modeling and calculation, a general rule for which it will honor warranty claims, or planning for mission fulfillment. The difference between service life and predicted life is most clear when considering mission time and reliability in comparison to MTBF and service life. For example, a missile system can have a mission time of less than one minute, service life of 20 years, active MTBF of 20 minutes, dormant MTBF of 50 years, and reliability of 99.9999%.
Consumers will have different expectations about service life and longevity[2][3] based upon factors such as use, cost, and quality.
Contents - Manufacturers will commit to very conservative service life, usually 2 to 5 years for most commercial and consumer products (for example computer peripherals and components). However, for large and expensive durable goods, the items are not consumable, and service lives and maintenance activity will factor large in the service life. Again, an airliner might have a mission time of 11 hours, a predicted active MTBF of 10,000 hours without maintenance (or 15,000 hours with maintenance), reliability of .99999, and a service life of 40 years.
Manufacturers will commit to very conservative service life, usually 2 to 5 years for most commercial and consumer products (for example computer peripherals and components). However, for large and expensive durable goods, the items are not consumable, and service lives and maintenance activity will factor large in the service life. Again, an airliner might have a mission time of 11 hours, a predicted active MTBF of 10,000 hours without maintenance (or 15,000 hours with maintenance), reliability of .99999, and a service life of 40 years.
The most common model for item lifetime is the bathtub curve, a plot of the varying failure rate as a function of time. During early life, the bathtub shows increased failures, usually witnessed during product development. The middle portion of the bathtub, or 'useful life', is a slightly inclined, nearly constant failure rate period where the consumer enjoys the benefit conferred by the product. As time increases further, the curve reaches a period of increasing failures, modeling the product's wear-out phase.
For an individual product, the component parts may each have independent service lives, resulting in several bathtub curves. For instance, a tire will have a service life partitioning related to the tread and the casing.
When exposed to high temperatures, the lithium-ion batteries in smartphones are easily damaged and can fail faster than expected, in addition to letting the device run out of battery too often. Debris and other contaminants that enter through small cracks in the phone can also infringe on smartphone life expectancy. One of the most common factors that cause smartphones and other electronic devices to die quickly is physical impact and breakage, which can severely damage the internal pieces.[4]
For maintainable items, those wear-out items that are determined by logistical analysis to be provisioned for sparing and replacement will assure a longer service life than manufactured items without such planning. A simple example is automotive tires - failure to plan for this wear out item would limit automotive service life to the extent of a single set of tires.
An individual tire's life follows the bathtub curve, to boot. After installation, there is a not-small probability of failure which may be related to material or workmanship or even to the process for mounting the tire which may introduce some small damage. After the initial period, the tire will perform, given no defect introducing events such as encountering a road hazard (a nail or a pothole), for a long duration relative to its expected service life which is a function of several variables (design, material, process). After a period, the failure probability will rise; for some tires, this will occur after the tread is worn out. Then, a secondary market for tires puts a retread on the tire thereby extending the service life. It is not uncommon for an 80,000-mile tire to perform well beyond that limit.[5]
It may be difficult to obtain reliable longevity data about many consumer products as, in general, efforts at actuarial analysis are not taken to the same extent as found with that needed to support insurance decisions. However, some attempts to provide this type of information have been made. An example is the collection of estimates for household components provided by the Old House Web[6] which gathers data from the Appliance Statistical Review and various institutes involved with the homebuilding trade.
Some Engine manufacturers, such as for example Navistar and Volvo, use a so-called B-life rating,[7] based on the durability data of the engine manufacturer,[8] B10 and B50 index for measuring the life expectancy of an engine.[9]
For certain products, such as those that cannot be serviced during their operational life for technical reasons, a manufacturer may calculate a product's expected performance at both the beginning of operational life (BOL) and end of operational life (EOL). Batteries and other components that degrade over time may affect the operation of a product. The performance of mission critical components is therefore calculated for EOL, with the components exceeding their specification at BOL. For example, with spaceflight hardware, which must survive in the harsh environment of space, the capacity to generate electricity from solar panels or radioisotope thermoelectric generator (RTG) is likely to reduce throughout a mission, but must still meet a specific requirement at EOL in order to complete the mission. A spacecraft may also have a BOL mass that is greater than its EOL mass as propellant is depleted during its operational life.
^ a b Cooper, Tim (1994). Beyond Recycling: the longer life option. London: New Economics Foundation. p. 5. ISBN 9781889407005.
^ Evans, Sian; Cooper, Tim (2010). "Consumer Influences on Product Life-Spans". In Cooper, Tim (ed.). Longer Lasting Products. Farnham: Gower. pp. 319350. ISBN 9780566088087.
Sound transmission class - Sound Transmission Class (or STC) is an integer rating of how well a building partition attenuates airborne sound. In the US, it is widely used to rate interior partitions, ceilings, floors, doors, windows and exterior wall configurations. Outside the US, the Sound Reduction Index (SRI) ISO index is used. The STC rating very roughly reflects the decibel reduction of noise that a partition can provide. The STC is useful for evaluating annoyance due to speech sounds, but not music or machinery noise as these sources contain more low frequency energy than speech.[1]
Sound Transmission Class (or STC) is an integer rating of how well a building partition attenuates airborne sound. In the US, it is widely used to rate interior partitions, ceilings, floors, doors, windows and exterior wall configurations. Outside the US, the Sound Reduction Index (SRI) ISO index is used. The STC rating very roughly reflects the decibel reduction of noise that a partition can provide. The STC is useful for evaluating annoyance due to speech sounds, but not music or machinery noise as these sources contain more low frequency energy than speech.[1]
There are many ways to improve the sound transmission class of a partition, though the two most basic principles are adding mass and increasing the overall thickness. In general, the sound transmission class of a double leaf wall (e.g. two 4"-thick brick walls separated by a 2" airspace) is greater than a single wall of equivalent mass (e.g. homogeneous 8" brick wall).[2]
The STC or sound transmission class is a single number method of rating how well wall partitions reduce sound transmission.[3] The STC provides a standardized way to compare products such as doors and windows made by competing manufacturers. A higher number indicates more effective sound insulation than a lower number. The STC is a standardized rating provided by ASTM E413 based on laboratory measurements performed in accordance with ASRM E90. ASTM E413 can also be used to determine similar ratings from field measurements performed in accordance with ASTM E336.[3]
Sound Isolation and Sound Insulation are used interchangeably, though the term "Insulation" is preferred outside the US.[4] The term "sound proofing" is typically avoided in architectural acoustics as it is a misnomer and connotes inaudibility.
Through research, acousticians have developed tables that pair a given STC rating with a subjective experience. The table below is used to determine the degree of sound isolation provided by typical multi-family construction. Generally, a difference of one or two STC points between similar constructions is subjectively insignificant.[5]
Good soundproofing; most sounds do not disturb neighboring residents.[6]
Tables like the one above are highly dependent on the background noise levels in the receiving room: the louder the background noise, the greater the perceived sound isolation.[7]
Prior to the STC rating, the sound isolation performance of a partition was measured and reported as the average transmission loss of over the frequency range 128 to 4096 Hz or 256 to 1021 Hz.[8][9] This method is valuable at comparing homogeneous partitions that follow the mass law, but can be misleading when comparing complex or multi-leaf walls.
In 1961, the ASTM International Standards Organization adopted E90-61T, which served as the basis for the STC method used today. The STC standard curve is based on European studies of multi-family residential construction, and closely resembles the sound isolation performance of a 9"-thick brick wall.[10]
Sound Transmission Class Report Sample from NTi Audio showing Transmission Loss in the sixteen standard frequencies
The STC number is derived from sound attenuation values tested at sixteen standard frequencies from 125 Hz to 4000 Hz. These Transmission Loss values are then plotted on a sound pressure level graph and the resulting curve is compared to a standard reference contour provided by the ASTM.[11]
Sound isolation metrics, such as the STC, are measured in specially-isolated and designed laboratory test chambers. There are nearly infinite field conditions that will affect sound isolation on site when designing building partitions and enclosures.
Sound travels through both the air and structure, and both paths must be considered when designing sound isolating walls and ceilings. To eliminate air borne sound all air paths between the areas must be eliminated. This is achieved by making seams airtight and closing all sound leaks. To eliminate structure-borne noise one must create isolation systems that reduce mechanical connections between those structures.[12]
Adding mass to a partition reduces the transmission of sound. This is often achieved by adding additional layers of gypsum. It is preferable to have non symmetrical leaves, for example with different thickness gypsum.[13] The effect of adding multiple layers of gypsum wallboard to a frame also varies depending on the framing type and configuration.[14] Doubling the mass of a partition does not double the STC, as the STC is calculated from a non-linear decibel sound transmission loss measurement.[15] So, whereas installing an additional layer of gypsum wallboard to a light-gauge (25-ga. or lighter) steel stud partition will result in about a 5 STC-point increase, doing the same on single wood or single heavy-gauge steel will result in only 2 to 3 additional STC points.[14] Adding a second additional layer (to the already 3-layer system) does not result in as drastic an STC change as the first additional layer.[16] The effect of additional gypsum wallboard layers on double- and staggered-stud partitions is similar to that of light-gauge steel partitions.
Due to increased mass, poured concrete and concrete blocks typically achieve higher STC values (in the mid STC 40s to the mid STC 50s) than equally thick framed walls.[17] However the additional weight, added complexity of construction, and poor thermal insulation tend to limit masonry wall partitions as a viable sound isolation solution in many building construction projects.
In recent years, gypsum board manufacturers have started to offer lightweight drywall board: Normal weight gypsum has a nominal density of 43pcf and lightweight drywall has a nominal density of 36pcf. This does not have a large effect on the STC rating, though lightweight gypsum can significantly degrade the low frequency performance of a partition as compared to normal weight gypsum.
Sound absorption entails turning acoustical energy into some other form of energy, usually heat.[18]
Adding absorptive materials to the interior surfaces of rooms, for example fabric-faced fiberglass panels and thick curtains, will result in a decrease of reverberated sound energy within the room. However, absorptive interior surface treatments of this kind do not significantly improve the sound transmission class.[19] Installing absorptive insulation, for example fiberglass batts and blow-in cellulose, into the wall or ceiling cavities does increase the sound transmission class significantly.[16] The presence of insulation in single 2x4 wood stud framing spaced 16" (406 mm) on-center results in only a few STC points. This is because a wall with 2x4 wood stud framing spaced 16" develops significant resonances which are not mitigated by the cavity insulation. In contrast, adding standard fiberglass insulation to an otherwise empty cavity in light-gauge (25-gauge or lighter) steel stud partitions can result in a nearly 10 STC-point improvement.
Other studies have shown that fibrous insulation materials, such as mineral wool, can increase the STC by 5 to 8 points.[13]
The effect of stiffness on sound isolation can relate to either the material stiffness of the sound isolating material or the stiffness caused by framing methods.
Structurally decoupling the gypsum wallboard panels from the partition framing can result in a large increase in sound isolation when installed correctly. Examples of structural decoupling in building construction include resilient channels, sound isolation clips and hat channels, and staggered- or double-stud framing. The STC results of decoupling in wall and ceiling assemblies varies significantly depending on the framing type, air cavity volume, and decoupling material type.[20] Great care must be taken in each type of decoupled partition construction, as any fastener that becomes mechanically (rigidly) coupled to the framing can short-circuit the decoupling and result in drastically lower sound isolation results.[21]
When two leaves are rigidly tied or coupled by a stud, the sound isolation of the system depends on the stiffness of the stud. Light-gauge (25-gauge or lighter) provides better sound isolation than 16-20-gauge steel, and noticeably better performance than wood studs.[22] When heavy gauge steel or wood studs are spaced 16" on center, additional resonances form which further lower the sound isolation performance of a partition. For typical gypsum stud walls, this resonance occurs in the 100160 Hz region and is thought to be a hybrid of the mass-air-mass resonance and a bending mode resonance caused when a plate is closely supported by stiff members.[23]
Single metal stud partitions are more effective than single wood stud partitions, and have been shown to increase the STC rating by up to 10 points. However, there is little difference between metal and wood studs when used in double stud partitions.[13] Double stud partitions have a higher STC than single stud.[13]
In certain assemblies, increasing the stud spacing from 16 to 24 inches increases the STC rating by 2 to 3 points.[13]
Though the terms sound absorption and damping are often interchangeable when discussing room acoustics, acousticians define these as two distinct properties of sound-isolating walls.
Several gypsum manufacturers offer specialty products which use constrained layer damping, which is a form of viscous damping.[24][25] Damping generally increases the sound isolation of partitions, particularly at mid-and-high frequencies.
Damping is also used to improve the sound isolation performance of glazing assemblies. Laminated glazing, which consists of a Polyvinyl butyral (or PVB) inter-layer, performs better acoustically than a non-laminated glass of equivalent thickness.[26]
A small gap in the wall can greatly reduce the STC rating. This wall did not receive a full perimeter seal.
All holes and gaps should be filled and the enclosure hermetically sealed for sound isolation to be effective. The table below illustrates sound proofing test results from a wall partition that has a theoretical maximum loss of 40 dB from one room to the next and a partition area of 10 meters squared. Even small open gaps and holes in the partition have a disproportionate reduction in sound proofing. A 5% opening in the partition, which offers unrestricted sound transmission from one room to the next, caused the transmission loss to reduces from 40 dB to 13 dB. A 0.1% open area will reduce the transmission loss from 40 dB to 30 dB, which is typical of walls where caulking has not been applied effectively[27] Partitions that are inadequately sealed and contain back-to-back electrical boxes, untreated recessed lighting and unsealed pipes offer flanking paths for sound and significant leakage.[28]
Acoustic joint tapes and caulking have been used to improve sound isolation since the early 1930s.[29] Although the applications of tapes was largely limited to defense and industrial applications such as naval vessels and aircraft in the past, recent research has proven the effectiveness of sealing gaps and thereby improving the sound isolation performance of a partition.[30]
Building codes typically allow for a 5-point tolerance between the lab-tested and field-measured STC rating; however, studies have shown that even in well-built and sealed installations the difference between the lab and field rating is highly dependent on the type of assembly.[31]
By nature, the STC rating is derived from lab testing under ideal conditions. There are other versions of the STC rating to account for real-world conditions.
The net sound isolation performance of a partition containing multiple sound isolating elements such as doors, windows, etc.
The sound isolation performance of a partition measured in the field according to ASTM E336, normalized to account for different room finishes and the area of the tested partition (i.e. compare the same wall measured in a bare living room and an acoustically dry recording booth).
The sound isolation performance of a partition measured in the field according to ASTM E336, normalized to account for the reverberation time in the room.
The sound isolation performance of a partition measured in the field according to ASTM E336, not normalized to the room conditions of the test.
The sound isolation performance of a specific elements in a partition, as measured in the field and achieved by suppressing the effects of sound flanking paths. This can be useful for measuring walls with doors, when you are interested in removing the influence of the door on the measured field STC. The FSTC testing method was historically prescribed by ASTM E336, however the latest version of this standard does not include FSTC.[32]
The sound isolation performance of doors when measured according to ASTM E2964.[33]
Section 1206 of International Building Code 2021 states that separation between dwelling units and public and service areas must achieve STC 50 where tested in accordance with ASTM E90, or NNIC 45 if field tested in accordance with ASTM E336. However, not all jurisdictions use the IBC for their building or municipal code.
Interior walls with 1 sheet of 1/2 (13 mm) gypsum wallboard (drywall) on either side of 2x4 (90 mm) wood studs spaced 16" (406 mm) on-center with no fiberglass insulation filling each stud cavity have an STC of about 33.[34] When asked to rate their acoustical performance, people often describe these walls as "paper thin." They offer little in the way of privacy. Double stud partition walls are typically constructed with varying gypsum wallboard panel layers attached to both sides of double 2x4 (90 mm) wood studs spaced 16" (406 mm) on-center and separated by a 1" (25 mm) airspace. These walls vary in sound isolation performance from the mid STC-40s into the high STC-60s depending on the presence of insulation and the gypsum wallboard type and quantity.[16] Commercial buildings are typically constructed using steel studs of varying widths, gauges, and on-center spacings. Each of these framing characteristics have an effect on the sound isolation of the partition to varying degrees.[35]
STC - Partition type
Partition type - 27
27 - Single pane glass window (typical value) (Dual pane glass window range is 2632)"STC Ratings".
Single pane glass window (typical value) (Dual pane glass window range is 2632)"STC Ratings".
33 - Single layer of 1/2 drywall on each side, wood studs, no insulation (typical interior wall)
Single layer of 1/2 drywall on each side, wood studs, no insulation (typical interior wall)
39 - Single layer of 1/2 drywall on each side, wood studs, fiberglass insulation [36]
Single layer of 1/2 drywall on each side, wood studs, fiberglass insulation [36]
Double layer of 1/2 drywall on each side, wood studs, batt insulation in wall
46 - Single layer of 1/2 drywall, glued to 6 lightweight concrete block wall, painted both sides
Single layer of 1/2 drywall, glued to 6 lightweight concrete block wall, painted both sides
8 Hollow CMU (Concrete Masonry Unit) with 2 Z-Bars and 1/2 Drywall on each side [38]
54 - Single layer of 1/2 drywall, glued to 8 dense concrete block wall, painted both sides
Single layer of 1/2 drywall, glued to 8 dense concrete block wall, painted both sides
54 - 8 Hollow CMU (Concrete Masonry Unit) with 1 1/2 Wood Furring, 1 1/2 Fiberglass Insulation and 1/2 Drywall on each side [38]
8 Hollow CMU (Concrete Masonry Unit) with 1 1/2 Wood Furring, 1 1/2 Fiberglass Insulation and 1/2 Drywall on each side [38]
55 - Double layer of 1/2 drywall on each side, on staggered wood stud wall, batt insulation in wall
Double layer of 1/2 drywall on each side, on staggered wood stud wall, batt insulation in wall
59 - Double layer of 1/2 drywall on each side, on wood stud wall, resilient channels on one side, batt insulation
Double layer of 1/2 drywall on each side, on wood stud wall, resilient channels on one side, batt insulation
63 - Double layer of 1/2 drywall on each side, on double wood/metal stud walls (spaced 1 apart), double batt insulation
Double layer of 1/2 drywall on each side, on double wood/metal stud walls (spaced 1 apart), double batt insulation
64 - 8 Hollow CMU (Concrete Masonry Unit) with 3 Steel Studs, Fiberglass Insulation and 1/2 Drywall on each side [38]
8 Hollow CMU (Concrete Masonry Unit) with 3 Steel Studs, Fiberglass Insulation and 1/2 Drywall on each side [38]
72 - 8 concrete block wall, painted, with 1/2 drywall on independent steel stud walls, each side, insulation in cavities
8 concrete block wall, painted, with 1/2 drywall on independent steel stud walls, each side, insulation in cavities
There are several commercially available software which predict the STC ratings of partitions using a combination of theoretical models and empirically-derived lab data. These programs can predict STC ratings within several points of a tested partition and are an approximation at best.[39]
The OutdoorIndoor Transmission Class (OITC) is a standard used for indicating the rate of sound transmission from outdoor noise sources into a building. It is based on the ASTM E-1332 Standard Classification for Rating Outdoor-Indoor Sound Attenuation.[40] Unlike the STC, which is based on a noise spectrum targeting speech sounds, OITC uses a source noise spectrum that considers frequencies down to 80 Hz (aircraft/rail/truck traffic) and is weighted more to lower frequencies. The OITC value is typically used to rate, evaluate, and select exterior glazing assemblies.
^ Berendt, Raymond D. (1967). A guide to airborne, impact, and structure borne noise-control in multifamily dwellings. U.S. Dept. of Housing and Urban Development. OCLC 5863574.
^ Bradley, J. S. (August 2001). Deriving Acceptable Values for Party Wall Sound Insulation from Survey Results. The 2001 International Congress and Exhibition on Noise Control Engineering. The Hague, The Netherlands. CiteSeerX 10.1.1.3.1115.
^ Cavanaugh, W. J.; Farrell, W. R.; Hirtle, P. W.; Watters, B. G. (April 1962). "Speech Privacy in Buildings". The Journal of the Acoustical Society of America. 34 (4): 475492. Bibcode:1962ASAJ...34..475C. doi:10.1121/1.1918154. ISSN 0001-4966.
^ Chrisler, V. L. (1939). Sound insulation of wall and floor constructions. U.S. G.P.O. OCLC 14104628.
^ Ballou 2008, p. 97. sfn error: no target: CITEREFBallou2008 (help)
^ Brown, Steven M.; Niedzielski, Joseph; Spalding, G. Robert (1978). "Effect of soundabsorptive facings on partition airbornesound transmission loss". The Journal of the Acoustical Society of America. 63 (6): 18511856. Bibcode:1978ASAJ...63.1851B. doi:10.1121/1.381924.
^ Halliwell, R. E. (1998). Gypsum board walls : transmission loss data. Institute for Research in Construction. OCLC 155721225.
^ Davy, John L.; Fard, Mohammad; Dong, Wayland; Loverde, John (February 2019). "Empirical corrections for predicting the sound insulation of double leaf cavity stud building elements with stiffer studs". The Journal of the Acoustical Society of America. 145 (2): 703713. Bibcode:2019ASAJ..145..703D. doi:10.1121/1.5089222. ISSN 0001-4966. PMID 30823783.
^ Shafer, Benjamin M.; Tinianov, Brandon (October 2011). "Use of damped drywall in architectural acoustics". The Journal of the Acoustical Society of America. 130 (4): 2388. Bibcode:2011ASAJ..130R2388S. doi:10.1121/1.3654567. ISSN 0001-4966.
^ Tinianov, Brian D. (September 2005). "Two case studies: QuietRock QR530 drywall panels in new and remediated multifamily construction". The Journal of the Acoustical Society of America. 118 (3): 1976. doi:10.1121/1.2097073. ISSN 0001-4966.
^ Monsanto Company. (1986). Acoustical glazing design guide : laminated glass with Saflex plastic interlayer for superior sound control. Monsanto Company. OCLC 38400395.
^ Ballou 2008, pp. 7778. sfn error: no target: CITEREFBallou2008 (help)
^ "Archived copy". Archived from the original on 2010-03-15. Retrieved 2012-02-07.CS1 maint: archived copy as title (link) Acoustics in Practice
^ Shafer, Benjamin M. (2013). An overview of constrained-layer damping theory and application. Proceedings of Meetings on Acoustics. 133. Acoustical Society of America. p. 065023. Bibcode:2013ASAJ..133.3332S. doi:10.1121/1.4800606.
^ Shafer, Benjamin M.; Tinianov, Brandon (2011). "Use of damped drywall in architectural acoustics". The Journal of the Acoustical Society of America. 130 (4): 2388. Bibcode:2011ASAJ..130R2388S. doi:10.1121/1.3654567.
^ LoVerde, John; Dong, Wayland (2010). "Predictability of field airborne noise isolation from laboratory testing". The Journal of the Acoustical Society of America. 127 (3): 1741. Bibcode:2010ASAJ..127.1741L. doi:10.1121/1.3383509. ISSN 0001-4966.
^ Standard Test Method for Measurement of the Normalized Insertion Loss of Doors, ASTM International, doi:10.1520/e2964-14
Cyril M. Harris. 1994. Noise Control in Buildings: A Practical Guide for Architects and Engineers.
Glenn M Ballou. 2008. Handbook for Sound Engineers 4ed. Elseveir. USA.
Are You Measuring Space Occupancy & Space Utilization?
The key to plugging the financial drain and maximizing workspace performance is by establishing better insight into two key areas: space occupancy and space utilization metrics.
Aside from the cost of employing your workforce, office space is likely one of your organizations largest investments. It also tends to be the most difficult to manage. With greater mobility and remote employment opportunities, business leaders are having an increasingly difficult time identifying wasted space and gauging the efficacy of space utilization.
But its nearly impossible to forecast the spatial needs of a facility over time without the ability to get space occupancy and space utilization metrics, which means planning for the future feels a lot like guesswork.
Cut back too much real estate and you risk creating efficiency and productivity issues, not to mention an uncomfortable work environment that leads to poor employee satisfaction or high turnover rates. Let too much space go unused, and your organization is throwing away money on utilities, maintenance, and property expenses that arent contributing to revenue or the health of your bottom line. Poor spatial use can also lead to collaboration issues and prevent your organization from developing a strong company culture.
We work in an incredibly competitive market that demands lean, optimized, and efficient operations. If your space doesnt fit the bill, productivity and revenue will undoubtedly suffer, and so will sustainability. But many facilities leaders arent exactly sure how to begin tackling the issue of space management.
It starts by understanding these two measurements: space occupancy and space utilization metrics
Space occupancy metrics - Space occupancy refers to the number of people in an office at a given period of time. Knowing this metric is important because it will determine how much space your facility actually requires to support its staff. To figure the amount of space required, facilities managers and workplace leaders must know:
Space occupancy refers to the number of people in an office at a given period of time. Knowing this metric is important because it will determine how much space your facility actually requires to support its staff. To figure the amount of space required, facilities managers and workplace leaders must know:
Total building capacity - Employees utilizing the space
Employees utilizing the space - Square footage of workspace
Square footage of workspace - Generally speaking, each employee should have anywhere from 125 to 225 square feet of usable office space. Of course, the nature of their job will determine if their actual spatial need is on the lower or higher end.
Generally speaking, each employee should have anywhere from 125 to 225 square feet of usable office space. Of course, the nature of their job will determine if their actual spatial need is on the lower or higher end.
It sounds simple, but facilities managers cant accurately reach square footage per employee without first knowing the true occupancy of their facility. And this isnt as easy as it sounds but well get to that.
Space utilization metrics - Space utilization metrics refer to how often a space is used, who uses it, and why its being used. Knowing this is important because space utilization metrics will help improve headcount accuracy and uncover important details about the actual purpose and priority of space. With this insight, workplace managers can determine whether space is being efficiently used to serve current and future business goals.
Space utilization metrics refer to how often a space is used, who uses it, and why its being used. Knowing this is important because space utilization metrics will help improve headcount accuracy and uncover important details about the actual purpose and priority of space. With this insight, workplace managers can determine whether space is being efficiently used to serve current and future business goals.
Here are a few key questions that will help you evaluate and measure space utilization metrics:
How big is your average workstation? (The average workstation today is 40-50 square feet, according to JLL's 2017 Office Outlook.)
What is the ratio of employees to workstations?
Is it possible for some employees to share desks if they aren't in the office every day?
How often are conference rooms being used? (According to HOK's 2014 Benchmarking Report, the average conference room utilization is only 23 percent.)
Before you can take steps to improve space utilization, you need to know your baseline numbers. You need to be able to look at your space utilization metrics.
Why both metrics matter - You cannot make educated decisions about spatial requirements, forecast for the future, budget, support operational goals and find opportunities to cut costs without reliable and objective data about who, how, and when space is being occupied and utilized.
You cannot make educated decisions about spatial requirements, forecast for the future, budget, support operational goals and find opportunities to cut costs without reliable and objective data about who, how, and when space is being occupied and utilized.
Space occupancy and space utilization metrics complete the full picture of what is required of a facility. But heres the catch: You cant accurately obtain one metric without the other.
Lets say youre trying to figure out your facilitys current occupancy percentage. Your workplace has a capacity for 300 employees, but currently only employs 200 people. By dividing the number of current employees (200) by the facilitys capacity (300), we get an occupancy percentage of just shy of 67%.
Seems simple enough, right? But this metric is actually not as clear-cut as you might think.
As mentioned above, an increasing number of organizations are opting in to flex scheduling or providing work-from-home opportunities. In other words, only a fraction of an organizations total staff is likely to be on-site or utilizing the facility at one time. This means space utilization metrics plays a major part in the true occupancy metric. Without understanding how space is utilized, the occupancy metric becomes an assumption instead of an approximate measurement.
How to accurately measure space occupancy and space utilization metrics
Sure, you could tirelessly take laps around your facility with a pad of paper and pen, marking down attendance, counting heads, noting what people are doing and where or, you could implement space management software. Rather than having to survey each space, space management software allows you to visualize your space and provides you with the ability to report on your actual space use.
That way, you can see the big-picture information in addition to specific details, like total area, location, buildings' floor-by-floor, and space-by-space utilization metrics.
This, coupled with scannable badges or wearables, allows you to track activity and generate a far more detailed report about how many occupants your facility supports throughout the day, where they spend the most time, and how they use different spaces.
From these reports, you can maximize your space utilization and minimize costs. You can determine if space is being utilized efficiently, if employee needs are being met by their environment, and if there is an opportunity to upgrade or downsize to increase productivity or decrease cost.
The more you know about the way your space is currently used, the better you can plan for the future. To optimize your workplace and improve workplace experience, you need to understand how space is being used and know how things are changing.
And at a time when budgets are tight, you also have to make sure you're paying attention to operating costs and maximizing the use of the real estate you do have.
Take time to better understand both your space occupancy and space utilization metrics, and you can improve your bottom line.
ABOUT THE AUTHOR - Adrian brings 20 years of experience in enterprise software sales in the EAM, IWMS & BI spaces. The experience he has gained from previous roles encompasses all that the iOFFICE products have to offer Canadian business, but now in one cohesive solution. He is a strong believer that Canadians like to partner with Canadians and his main drivers are; client satisfaction, client advocacy and making sure his clients receive value from the solutions he represents. He has built a successful career based on this philosophy and looks forward to bringing his knowledge and the value of the iOFFICE suite to the Canadian marketplace.
Adrian brings 20 years of experience in enterprise software sales in the EAM, IWMS & BI spaces. The experience he has gained from previous roles encompasses all that the iOFFICE products have to offer Canadian business, but now in one cohesive solution. He is a strong believer that Canadians like to partner with Canadians and his main drivers are; client satisfaction, client advocacy and making sure his clients receive value from the solutions he represents. He has built a successful career based on this philosophy and looks forward to bringing his knowledge and the value of the iOFFICE suite to the Canadian marketplace.
In thermodynamics, the specific heat capacity or occasionally massic heat capacity (symbol cp) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample. Informally, it is the amount of energy that must be added, in the form of heat, to one unit of mass of the substance in order to cause an increase of one unit in temperature. The SI unit of specific heat capacity is joule per kelvin per kilogram, Jkg1K1.[1] For example, the heat required to raise the temperature of 1 kg of water by 1 K is 4184 joules so the specific heat capacity of water is 4184 Jkg1K1.[2]
The specific heat capacity often varies with temperature, and is different for each state of matter. Liquid water has one of the highest specific heat capacities among common substances, about 4184 Jkg1K1 at 20 C; but that of ice just below 0 C is only 2093 Jkg1K1. The specific heat capacities of iron, granite, and hydrogen gas are about 449 Jkg1K1, 790 Jkg1K1, and 14300 Jkg1K1, respectively.[3] While the substance is undergoing a phase transition, such as melting or boiling, its specific heat capacity is technically infinite, because the heat goes into changing its state rather than raising its temperature.
The specific heat capacity of a substance, especially a gas, may be significantly higher when it is allowed to expand as it is heated (specific heat capacity at constant pressure) than when is heated in a closed vessel that prevents expansion (specific heat capacity at constant volume). These two values are usually denoted by c p {\displaystyle c_{p}} and c V {\displaystyle c_{V}} , respectively; their quotient = c p / c V {\displaystyle \gamma =c_{p}/c_{V}} is the heat capacity ratio.
The term specific heat may refer to the ratio between the specific heat capacities of a substance at a given temperature and of a reference substance at a reference temperature, such as water at 15 C;[4] much in the fashion of specific gravity.
Specific heat capacity relates to other intensive measures of heat capacity with other denominators. If the amount of substance is measured as a number of moles, one gets the molar heat capacity instead (whose SI unit is joule per kelvin per mole, Jmol1K1. If the amount is taken to be the volume of the sample (as is sometimes done in engineering), one gets the volumetric heat capacity (whose SI unit is joule per kelvin per cubic meter, Jm3K1).
One of the first scientists to use the concept was Joseph Black, 18th-century medical doctor and professor of Medicine at Glasgow University. He measured the specific heat capacities of many substances, using the term capacity for heat.[5]
The specific heat capacity of a substance, usually denoted by c {\displaystyle c} , is the heat capacity C {\displaystyle C} of a sample of the substance, divided by the mass M {\displaystyle M} of the sample:[6]
where d Q {\displaystyle \mathrm {d} Q} represents the amount of heat needed to uniformly raise the temperature of the sample by a small increment d T {\displaystyle \mathrm {d} T} .
Like the heat capacity of an object, the specific heat capacity of a substance may vary, sometimes substantially, depending on the starting temperature T {\displaystyle T} of the sample and the pressure p {\displaystyle p} applied to it. Therefore, it should be considered a function c ( p , T ) {\displaystyle c(p,T)} of those two variables.
These parameters are usually specified when giving the specific heat capacity of a substance. For example, "Water (liquid): c p {\displaystyle c_{p}} = 4187 Jkg1K1 (15 C)" [7] When not specified, published values of the specific heat capacity c {\displaystyle c} generally are valid for some standard conditions for temperature and pressure.
However, the dependency of c {\displaystyle c} on starting temperature and pressure can often be ignored in practical contexts, e.g. when working in narrow ranges of those variables. In those contexts one usually omits the qualifier ( p , T ) {\displaystyle (p,T)} , and approximates the specific heat capacity by a constant c {\displaystyle c} suitable for those ranges.
Specific heat capacity is an intensive property of a substance, an intrinsic characteristic that does not depend on the size or shape of the amount in consideration. (The qualifier "specific" in front of an extensive property often indicates an intensive property derived from it.[8])
The injection of heat energy into a substance, besides raising its temperature, usually causes an increase in its volume and/or its pressure, depending on how the sample is confined. The choice made about the latter affects the measured specific heat capacity, even for the same starting pressure p {\displaystyle p} and starting temperature T {\displaystyle T} . Two particular choices are widely used:
If the pressure is kept constant (for instance, at the ambient atmospheric pressure), and the sample is allowed to expand, the expansion generates work as the force from the pressure displaces the enclosure or the surrounding fluid. That work must come from the heat energy provided. The specific heat capacity thus obtained is said to be measured at constant pressure (or isobaric), and is often denoted c p {\displaystyle c_{p}} , c p {\displaystyle c_{\mathrm {p} }} , etc.
On the other hand, if the expansion is prevented for example by a sufficiently rigid enclosure, or by increasing the external pressure to counteract the internal one no work is generated, and the heat energy that would have gone into it must instead contribute to the internal energy of the sample, including raising its temperature by an extra amount. The specific heat capacity obtained this way is said to be measured at constant volume (or isochoric) and denoted c V {\displaystyle c_{V}} , c v {\displaystyle c_{v}} c v {\displaystyle c_{\mathrm {v} }} , etc.
The value of c V {\displaystyle c_{V}} is usually less than the value of c p {\displaystyle c_{p}} . This difference is particularly notable in gases where values under constant pressure are typically 30% to 66.7% greater than those at constant volume. Hence the heat capacity ratio of gases is typically between 1.3 and 1.67.[9]
The specific heat capacity can be defined and measured for gases, liquids, and solids of fairly general composition and molecular structure. These include gas mixtures, solutions and alloys, or heterogenous materials such as milk, sand, granite, and concrete, if considered at a sufficiently large scale.
The specific heat capacity can be defined also for materials that change state or composition as the temperature and pressure change, as long as the changes are reversible and gradual. Thus, for example, the concepts are definable for a gas or liquid that dissociates as the temperature increases, as long as the products of the dissociation promptly and completely recombine when it drops.
The specific heat capacity is not meaningful if the substance undergoes irreversible chemical changes, or if there is a phase change, such as melting or boiling, at a sharp temperature within the range of temperatures spanned by the measurement.
The specific heat capacity of a substance is typically determined according to the definition; namely, by measuring the heat capacity of a sample of the substance, usually with a calorimeter, and dividing by the sample's mass . Several techniques can be applied for estimating the heat capacity of a substance as for example fast differential scanning calorimetry.[10][11]
Graph of temperature of phases of water heated from 100 C to 200 C the dashed line example shows that melting and heating 1 kg of ice at 50 C to water at 40 C needs 600 kJ
The specific heat capacities of gases can be measured at constant volume, by enclosing the sample in a rigid container. On the other hand, measuring the specific heat capacity at constant volume can be prohibitively difficult for liquids and solids, since one often would need impractical pressures in order to prevent the expansion that would be caused by even small increases in temperature. Instead, the common practice is to measure the specific heat capacity at constant pressure (allowing the material to expand or contract as it wishes), determine separately the coefficient of thermal expansion and the compressibility of the material, and compute the specific heat capacity at constant volume from these data according to the laws of thermodynamics.[citation needed]
The SI unit for specific heat capacity is joule per kelvin per kilogram ((J/K)/kg, J/(kgK), JK1kg1, etc.). Since an increment of temperature of one degree Celsius is the same as an increment of one kelvin, that is the same as joule per degree Celsius per kilogram (Jkg1C1). Sometimes the gram is used instead of kilogram for the unit of mass: 1 Jg1K1 = 0.001 Jkg1K1.
The specific heat capacity of a substance (per unit of mass) has dimension L21T2, or (L/T)2/. Therefore, the SI unit Jkg1K1 is equivalent to metre squared per second squared per kelvin (m2K1s2).
In those contexts, the unit of specific heat capacity is BTUF1lb1 = 4177.6 Jkg1K1. The BTU was originally defined so that the average specific heat capacity of water would be 1 BTUF1lb1.
In chemistry, heat amounts were often measured in calories. Confusingly, two units with that name, denoted "cal" or "Cal", have been commonly used to measure amounts of heat:
the "small calorie" (or "gram-calorie", "cal") is 4.184 J, exactly. It was originally defined so that the specific heat capacity of liquid water would be 1 calC1g1.
The "grand calorie" (also "kilocalorie", "kilogram-calorie", or "food calorie"; "kcal" or "Cal") is 1000 small calories, that is, 4184 J, exactly. It was originally defined so that the specific heat capacity of water would be 1 CalC1kg1.
While these units are still used in some contexts (such as kilogram calorie in nutrition), their use is now deprecated in technical and scientific fields. When heat is measured in these units, the unit of specific heat capacity is usually
In either unit, the specific heat capacity of water is approximately 1. The combinations calC1kg1 = 4.184 Jkg1K1 and kcalC1g1 = 4,184,000 Jkg1K1 do not seem to be widely used.
The temperature of a sample of a substance reflects the average kinetic energy of its constituent particles (atoms or molecules) relative to its center of mass. However, not all energy provided to a sample of a substance will go into raising its temperature, exemplified via the equipartition theorem.
Quantum mechanics predicts that, at room temperature and ordinary pressures, an isolated atom in a gas cannot store any significant amount of energy except in the form of kinetic energy. Thus, heat capacity per mole is the same for all monatomic gases (such as the noble gases). More precisely, c V , m = 3 R / 2 {\displaystyle c_{V,\mathrm {m} }=3R/2\approx {}} 12.5 JK1mol1 and c P , m = 5 R / 2 {\displaystyle c_{P,\mathrm {m} }=5R/2\approx {}} 21 JK1mol1, where R {\displaystyle R\approx {}} 8.31446 JK1mol1 is the ideal gas unit (which is the product of Boltzmann conversion constant from kelvin microscopic energy unit to the macroscopic energy unit joule, and the Avogadro number).
Therefore, the specific heat capacity (per unit of mass, not per mole) of a monatomic gas will be inversely proportional to its (adimensional) atomic weight A {\displaystyle A} . That is, approximately,
c V {\displaystyle c_{V}\approx {}} 12470 JK1kg1 / A c p {\displaystyle /A\quad \quad \quad c_{p}\approx {}} 20785 JK1kg1 / A {\displaystyle /A}
For the noble gases, from helium to xenon, these computed values are
On the other hand, a polyatomic gas molecule (consisting of two or more atoms bound together) can store heat energy in other forms besides its kinetic energy. These forms include rotation of the molecule, and vibration of the atoms relative to its center of mass.
These extra degrees of freedom or "modes" contribute to the specific heat capacity of the substance. Namely, when heat energy is injected into a gas with polyatomic molecules, only part of it will go into increasing their kinetic energy, and hence the temperature; the rest will go to into those other degrees of freedom. In order to achieve the same increase in temperature, more heat energy will have to be provided to a mol of that substance than to a mol of a monatomic gas. Therefore, the specific heat capacity of a polyatomic gas depends not only on its molecular mass, but also on the number of degrees of freedom that the molecules have.[14][15][16]
Quantum mechanics further says that each rotational or vibrational mode can only take or lose energy in certain discrete amount (quanta). Depending on the temperature, the average heat energy per molecule may be too small compared to the quanta needed to activate some of those degrees of freedom. Those modes are said to be "frozen out". In that case, the specific heat capacity of the substance is going to increase with temperature, sometimes in a step-like fashion, as more modes become unfrozen and start absorbing part of the input heat energy.
For example, the molar heat capacity of nitrogen N 2 at constant volume is c V , m = {\displaystyle c_{V,\mathrm {m} }={}} 20.6 JK1mol1 (at 15 C, 1 atm), which is 2.49 R {\displaystyle R} .[17] That is the value expected from theory if each molecule had 5 degrees of freedom. These turn out to be three degrees of the molecule's velocity vector, plus two degrees from its rotation about an axis through the center of mass and perpendicular to the line of the two atoms. Because of those two extra degrees of freedom, the specific heat capacity c V {\displaystyle c_{V}} of N 2 (736 JK1kg1) is greater than that of an hypothetical monatomic gas with the same molecular mass 28 (445 JK1kg1), by a factor of 5/3.
This value for the specific heat capacity of nitrogen is practically constant from below 150 C to about 300 C. In that temperature range, the two additional degrees of freedom that correspond to vibrations of the atoms, stretching and compressing the bond, are still "frozen out". At about that temperature, those modes begin to "un-freeze", and as a result c V {\displaystyle c_{V}} starts to increase rapidly at first, then slower as it tends to another constant value. It is 35.5 JK1mol1 at 1500 C, 36.9 at 2500 C, and 37.5 at 3500 C.[18] The last value corresponds almost exactly to the predicted value for 7 degrees of freedom per molecule.
In theory, the specific heat capacity of a substance can also be derived from its abstract thermodynamic modeling by an equation of state and an internal energy function.
To apply the theory, one considers the sample of the substance (solid, liquid, or gas) for which the specific heat capacity can be defined; in particular, that it has homogeneous composition and fixed mass M {\displaystyle M} . Assume that the evolution of the system is always slow enough for the internal pressure P {\displaystyle P} and temperature T {\displaystyle T} be considered uniform throughout. The pressure P {\displaystyle P} would be equal to the pressure applied to it by the enclosure or some surrounding fluid, such as air.
The state of the material can then be specified by three parameters: its temperature T {\displaystyle T} , the pressure P {\displaystyle P} , and its specific volume V = V / M {\displaystyle V={\boldsymbol {\mathrm {V} }}/M} , where V {\displaystyle {\boldsymbol {\mathrm {V} }}} is the volume of the sample. (This quantity is the reciprocal 1 / {\displaystyle 1/\rho } of the material's density = M / V {\displaystyle \rho =M/{\boldsymbol {\mathrm {V} }}} .) Like T {\displaystyle T} and P {\displaystyle P} , the specific volume V {\displaystyle V} is an intensive property of the material and its state, that does not depend on the amount of substance in the sample.
Those variables are not independent. The allowed states are defined by an equation of state relating those three variables: F ( T , P , V ) = 0. {\displaystyle F(T,P,V)=0.} The function F {\displaystyle F} depends on the material under consideration. The specific internal energy stored internally in the sample, per unit of mass, will then be another function U ( T , P , V ) {\displaystyle U(T,P,V)} of these state variables, that is also specific of the material. The total internal energy in the sample then will be M U ( T , P , V ) {\displaystyle MU(T,P,V)} .
For some simple materials, like an ideal gas, one can derive from basic theory the equation of state F = 0 {\displaystyle F=0} and even the specific internal energy U {\displaystyle U} In general, these functions must be determined experimentally for each substance.
The absolute value of this quantity is undefined, and (for the purposes of thermodynamics) the state of "zero internal energy" can be chosen arbitrarily. However, by the law of conservation of energy, any infinitesimal increase M d U {\displaystyle M\mathrm {d} U} in the total internal energy M U {\displaystyle MU} must be matched by the net flow of heat energy d Q {\displaystyle \mathrm {d} Q} into the sample, plus any net mechanical energy provided to it by enclosure or surrounding medium on it. The latter is P d V {\displaystyle -P\mathrm {d} {\boldsymbol {\mathrm {V} }}} , where d V {\displaystyle \mathrm {d} {\boldsymbol {\mathrm {V} }}} is the change in the sample's volume in that infinitesimal step.[19] Therefore
If the volume of the sample (hence the specific volume of the material) is kept constant during the injection of the heat amount d Q {\displaystyle \mathrm {d} Q} , then the term P d V {\displaystyle P\mathrm {d} V} is zero (no mechanical work is done). Then, dividing by d T {\displaystyle \mathrm {d} T} ,
where d T {\displaystyle \mathrm {d} T} is the change in temperature that resulted from the heat input. The left-hand side is the specific heat capacity at constant volume c V {\displaystyle c_{V}} of the material.
For the heat capacity at constant pressure, it is useful to define the specific enthalpy of the system as the sum H ( T , P , V ) = U ( T , P , V ) + P V {\displaystyle H(T,P,V)=U(T,P,V)+PV} . An infinitesimal change in the specific enthalpy will then be
If the pressure is kept constant, the second term on the left-hand side is zero, and
The left-hand side is the specific heat capacity at constant pressure c P {\displaystyle c_{P}} of the material.
In general, the infinitesimal quantities d T , d P , d V , d U {\displaystyle \mathrm {d} T,\mathrm {d} P,\mathrm {d} V,\mathrm {d} U} are constrained by the equation of state and the specific internal energy function. Namely,
Here ( F / T ) ( T , P , V ) {\displaystyle (\partial F/\partial T)(T,P,V)} denotes the (partial) derivative of the state equation F {\displaystyle F} with respect to its T {\displaystyle T} argument, keeping the other two arguments fixed, evaluated at the state ( T , P , V ) {\displaystyle (T,P,V)} in question. The other partial derivatives are defined in the same way. These two equations on the four infinitesimal increments normally constrain them to a two-dimensional linear subspace space of possible infinitesimal state changes, that depends on the material and on the state. The constant-volume and constant-pressure changes are only two particular directions in this space.
For any specific volume V {\displaystyle V} , denote p V ( T ) {\displaystyle p_{V}(T)} the function that describes how the pressure varies with the temperature T {\displaystyle T} , as allowed by the equation of state, when the specific volume of the material is forcefully kept constant at V {\displaystyle V} . Analogously, for any pressure P {\displaystyle P} , let v P ( T ) {\displaystyle v_{P}(T)} be the function that describes how the specific volume varies with the temperature, when the pressure is kept constant at P {\displaystyle P} . Namely, those functions are such that
for any values of T , P , V {\displaystyle T,P,V} . In other words, the graphs of p V ( T ) {\displaystyle p_{V}(T)} and v P ( T ) {\displaystyle v_{P}(T)} are slices of the surface defined by the state equation, cut by planes of constant V {\displaystyle V} and constant P {\displaystyle P} , respectively.
both depending on the state ( T , P , V ) {\displaystyle (T,P,V)} .
The heat capacity ratio, or adiabatic index, is the ratio c P / c V {\displaystyle c_{P}/c_{V}} of the heat capacity at constant pressure to heat capacity at constant volume. It is sometimes also known as the isentropic expansion factor.
The path integral Monte Carlo method is a numerical approach for determining the values of heat capacity, based on quantum dynamical principles. However, good approximations can be made for gases in many states using simpler methods outlined below. For many solids composed of relatively heavy atoms (atomic number > iron), at non-cryogenic temperatures, the heat capacity at room temperature approaches 3R = 24.94 joules per kelvin per mole of atoms (DulongPetit law, R is the gas constant). Low temperature approximations for both gases and solids at temperatures less than their characteristic Einstein temperatures or Debye temperatures can be made by the methods of Einstein and Debye discussed below.
The differences in heat capacities as defined by the above Mayer relation is only exact for an ideal gas and would be different for any real gas. -->
^ (2001): Columbia Encyclopedia, 6th ed.; as quoted by Encyclopedia.com. Columbia University Press. Accessed on 2019-04-11.
^ International Union of Pure and Applied Chemistry, Physical Chemistry Division. "Quantities, Units and Symbols in Physical Chemistry" (PDF). Blackwell Sciences. p. 7. The adjective specific before the name of an extensive quantity is often used to mean divided by mass.
^ Lange's Handbook of Chemistry, 10th ed. page 1524
^ Koch, Werner (2013). VDI Steam Tables (4 ed.). Springer. p. 8. ISBN 9783642529412. Published under the auspices of the Verein Deutscher Ingenieure (VDI).
^ Kittel, Charles and Kroemer, Herbert (2000). Thermal physics. Freeman. p. 78. ISBN 978-0-7167-1088-2.CS1 maint: multiple names: authors list (link)
^ Thornton, Steven T. and Rex, Andrew (1993) Modern Physics for Scientists and Engineers, Saunders College Publishing
^ Cengel, Yunus A. and Boles, Michael A. (2010) Thermodynamics: An Engineering Approach, 7th Edition, McGraw-Hill ISBN 007-352932-X.
Emmerich Wilhelm & Trevor M. Letcher, Eds., 2010, Heat Capacities: Liquids, Solutions and Vapours, Cambridge, U.K.:Royal Society of Chemistry, ISBN 0-85404-176-1. A very recent outline of selected traditional aspects of the title subject, including a recent specialist introduction to its theory, Emmerich Wilhelm, "Heat Capacities: Introduction, Concepts, and Selected Applications" (Chapter 1, pp. 127), chapters on traditional and more contemporary experimental methods such as photoacoustic methods, e.g., Jan Thoen & Christ Glorieux, "Photothermal Techniques for Heat Capacities," and chapters on newer research interests, including on the heat capacities of proteins and other polymeric systems (Chs. 16, 15), of liquid crystals (Ch. 17), etc.
Stairs - Construction designed to bridge a large vertical distance by dividing it into steps
Construction designed to bridge a large vertical distance by dividing it into steps
Stairs, a stairway, a staircase, a stairwell, or a flight of stairs is a construction designed to bridge a large vertical distance by dividing it into smaller vertical distances, called steps. Stairs may be straight, round, or may consist of two or more straight pieces connected at angles.
A stair, or a stairstep, is one step in a flight of stairs.[2] In buildings, stairs is a term applied to a complete flight of steps between two floors. A stair flight is a run of stairs or steps between landings. A staircase or stairway is one or more flights of stairs leading from one floor to another, and includes landings, newel posts, handrails, balustrades and additional parts. A stairwell is a compartment extending vertically through a building in which stairs are placed. A stair hall is the stairs, landings, hallways, or other portions of the public hall through which it is necessary to pass when going from the entrance floor to the other floors of a building. Box stairs are stairs built between walls, usually with no support except the wall strings.[2]
Stairs may be in a "straight run", leading from one floor to another without a turn or change in direction. Stairs may change direction, commonly by two straight flights connected at a 90 degree angle landing. Stairs may also return onto themselves with 180 degree angle landings at each end of straight flights forming a vertical stairway commonly used in multistory and highrise buildings. Many variations of geometrical stairs may be formed of circular, elliptical and irregular constructions.[2]
Stairs may be a required component of egress from structures and buildings. Stairs are also provided for convenience to access floors, roofs, levels and walking surfaces not accessible by other means. Stairs may also be a fanciful physical construct such as the "stairs that go nowhere" located at the Winchester Mystery House. Stairs are also a subject used in art to represent real or imaginary places built around impossible objects using geometric distortion, as in the work of artist M. C. Escher.
"Stairway" is also a common metaphor for achievement or loss of a position in the society; or as a metaphor of hierarchy (e.g. Jacob's Ladder, Battleship Potemkin).
Steps with 2 anti-slip rubber lines and small nosings
Each step is composed of a tread and a riser. Some include nosing.
Tread: The part of the stairway that is stepped on. It is constructed to the same specifications (thickness) as any other flooring. The tread "depth" is measured from the back of one tread to the back of the next. The "width" is measured from one side to the other.
Riser: The vertical portion between each tread on the stair. This may be missing for an "open" stair effect.
Nosing: An edge part of the tread that protrudes over the riser beneath. If it is present, this means that, measured horizontally, the total "run" length of the stairs is not simply the sum of the tread lengths, as the treads overlap each other. Many building codes require stair nosings for commercial, industrial, or municipal stairs.[3] They provide additional length to the tread without changing the pitch of the stairs.
Starting or feature tread: Where stairs are open on one or both sides, the first step above the lower floor or landing may be wider than the other steps and rounded. When the starting step is rounded, the balusters typically form a spiral around the circumference of the rounded portion, and the handrail has a spiral called a "volute" that supports the top of the balusters. Besides the cosmetic appeal, starting steps allow the balusters to form a wider, more stable base for the end of the handrail. Handrails that simply end at a post at the foot of the stairs can be less sturdy, even with a thick post. A double ended feature tread can be used when both sides of the stairs are open. There are a number of different styles and uses of feature tread.
Stringer board, stringer, or sometimes just string::The structural member that supports the treads and risers in standard staircases. There are typically three stringers, one on either side and one in the centre, with more added as necessary for wider spans. Side stringers are sometimes dadoed to receive risers and treads for increased support. Stringers on open-sided stairs are called "cut stringers".
Tread rise: The distance from the top of one tread to the top of the next tread.
Total rise: The distance the flight of stairs raises vertically between two finished floor levels.
Winders::Winders are steps that are narrower on one side than the other. They are used to change the direction of the stairs without landings. A series of winders form a circular or spiral stairway. When three steps are used to turn a 90 corner, the middle step is called a kite winder as a kite-shaped quadrilateral.
Trim::Various moldings are used to decorate and in some instances support stairway elements. Scotia or quarter-round are typically placed beneath the nosing to support its overhang.
A decorative step at the bottom of the staircase which usually houses the volute and volute newel turning for a continuous handrail. The curtail tread will follow the flow of the volute.[4]
Example of winder stairs with a simple handrail supported by three newel posts
The balustrade is the system of railings and balusters that prevents people from falling over the edge.
Banister, railing, or handrail: The angled member for handholding, as distinguished from the vertical balusters which hold it up for stairs that are open on one side. Railings are often present on both sides of stairs, but can sometimes be only on one side or absent altogether. On wide staircases, there can be one or more railings in between the two sides. The term "banister" is sometimes used to mean just the handrail, sometimes the handrail and the balusters, or sometimes just the balusters.[5]
Volute: A handrail end element for the bullnose step that curves inward like a spiral. A volute is said to be right or left-handed depending on which side of the stairs the handrail is as one faces up the stairs.
Turnout: Instead of a complete spiral volute, a turnout deviates from the normal handrail centre line away from the flight to give a wider opening as one enters the staircase, The turnout is usually set over a newel post to give added stability to the handrail.
Gooseneck: The vertical handrail that joins a sloped handrail to a higher handrail on the balcony or landing is a gooseneck.
Rosette: Where the handrail ends in the wall and a half-newel is not used, it may be trimmed by a rosette.
Easings: Wall handrails are mounted directly onto the wall with wall brackets. At the bottom of the stairs such railings flare to a horizontal railing and this horizontal portion is called a "starting easing". At the top of the stairs, the horizontal portion of the railing is called a "over easing".
Core rail: Wood handrails often have a metal core to provide extra strength and stiffness, especially when the rail has to curve against the grain of the wood. The archaic term for the metal core is "core rail".
Baluster: A term for the vertical posts that hold up the handrail. Sometimes simply called guards or spindles. Treads often require two balusters. The second baluster is closer to the riser and is taller than the first. The extra height in the second baluster is typically in the middle between decorative elements on the baluster. That way the bottom decorative elements are aligned with the tread and the top elements are aligned with the railing angle.
Newel: A large baluster or post used to anchor the handrail. Since it is a structural element, it extends below the floor and subfloor to the bottom of the floor joists and is bolted right to the floor joist. A half-newel may be used where a railing ends in the wall. Visually, it looks like half the newel is embedded in the wall. For open landings, a newel may extend below the landing for a decorative newel drop.
Finial: A decorative cap to the top of a newel post, particularly at the end of the balustrade.
Baserail, or shoerail: For systems where the baluster does not start at the treads, they go to a baserail. This allows for identical balusters, avoiding the second baluster problem.
Fillet: A decorative filler piece on the floor between balusters on a balcony railing.
Handrails may be continuous (sometimes called over-the-post) or post-to-post (or more accurately newel-to-newel). For continuous handrails on long balconies, there may be multiple newels and tandem caps to cover the newels. At corners, there are quarter-turn caps. For post-to-post systems, the newels project above the handrails.
Another, more classical, form of handrailing which is still in use is the tangent method. A variant of the Cylindric method of layout, it allows for continuous climbing and twisting rails and easings. It was defined from principles set down by architect Peter Nicholson in the 18th century.
The earliest spiral staircases appear in Temple A in the Greek colony Selinunte, Sicily, to both sides of the cella. The temple was constructed around 480470 BC.[6]
Staircase in Ford plant in Los Angeles with double bullnose and two volutes. An intermediate landing is part of this U-shaped stair.
Apron - This is a wooden fascia board used to cover up trimmers and joists exposed by stairwell openings. The apron may be moulded or plain, and is intended to give the staircase a cleaner look by cloaking the side view.[7]
This is a wooden fascia board used to cover up trimmers and joists exposed by stairwell openings. The apron may be moulded or plain, and is intended to give the staircase a cleaner look by cloaking the side view.[7]
Balcony: For stairs with an open concept upper floor or landing, the upper floor is functionally a balcony. For a straight flight of stairs, the balcony may be long enough to require multiple newels to support the length of railing.
Flight: A flight is an uninterrupted series of steps.
Floating stairs: A flight of stairs is said to be "floating" if there is nothing underneath. The risers are typically missing as well to emphasize the open effect, and create a functional feature suspended in midair.[8] There may be only one stringer or the stringers otherwise minimized. Where building codes allow, there may not even be handrails.
Landing, or platform: A landing is the area of a floor near the top or bottom step of a stair. An intermediate landing is a small platform that is built as part of the stair between main floor levels and is typically used to allow stairs to change directions, or to allow the user a rest. A half landing, or half-pace, is where a 180 change in direction is made, and a quarter landing is where a 90 change in direction is made (on an intermediate landing).[9] As intermediate landings consume floor space, they can be expensive to build. However, changing the direction of the stairs allows stairs to fit where they would not otherwise, or provides privacy to the upper level as visitors downstairs cannot simply look up the stairs to the upper level due to the change in direction. The word 'landing' is also commonly used for a general corridor in any of the floors above the ground floor of a building, even if that corridor is located well away from a staircase.
Mobile safety steps: Can be used as temporary, safe replacements for many types of stairs
Runner: Carpeting that runs down the middle of the stairs. Runners may be directly stapled or nailed to the stairs, or may be secured by a specialized bar, known as a stair rod, that holds the carpet in place where the tread meets the riser.
Spandrel: If there is not another flight of stairs immediately underneath, the triangular space underneath the stairs is called a "spandrel". It is frequently used as a closet.
Staircase: This term is often reserved for the stairs themselves: the steps, railings and landings; though often it is used interchangeably with "stairs" and "stairway". In the UK, however, the term "staircase" denotes what in the U.S. is called "stairway", but usually includes the casing the walls, bannisters and underside of the stairs or roof above.
Stairway: This primarily American term is often reserved for the entire stairwell and staircase in combination;[citation needed] though often it is used interchangeably with "stairs" and "staircase".
Stairwell: The spatial opening, usually a vertical shaft, containing an indoor stairway; by extension it is often used as including the stairs it contains.
Staircase tower: A tower attached to, or incorporated into, a building that contains stairs linking the various floors.
The measurements of a stair, in particular the rise height and going of the steps, should remain the same along the stairs.[10]
The following stair measurements are important: - The rise height or rise of each step is measured from the top of one tread to the next. It is not the physical height of the riser; the latter excludes the thickness of the tread. A person using the stairs would move this distance vertically for each step taken.
The rise height or rise of each step is measured from the top of one tread to the next. It is not the physical height of the riser; the latter excludes the thickness of the tread. A person using the stairs would move this distance vertically for each step taken.
The tread depth of a step is measured from the edge of the nosing to the vertical riser; if the steps have no nosing, it is the same as the going; otherwise it is the going plus the extent of one nosing.
The going of a step is measured from the edge of the nosing to the edge of nosing in plan view. A person using the stairs would move this distance forward with each step they take.
To avoid confusion, the number of steps in a set of stairs is always the number of risers, not the number of treads.
The total run or total going of the stairs is the horizontal distance from the first riser to the last riser. It is often not simply the sum of the individual tread lengths due to the nosing overlapping between treads. If there are N steps, the total run equals N-1 times the going: the tread of the first step is part of a landing.
The total rise of the stairs is the height between floors (or landings) that the flight of stairs is spanning. If there are N steps, the total rise equals N times the rise of each step.
A quite unusual "variable rise" stairway, which also distorts visual perspective (at The Duomo in Urbino, Italy)
The slope or pitch of the stairs is the ratio between the rise and the going (not the tread depth, due to the nosing). It is sometimes called the rake of the stairs. The pitch line is the imaginary line along the tip of the nosing of the treads. In the UK, stair pitch is the angle the pitch line makes with the horizontal, measured in degrees. The value of the slope, as a ratio, is then the tangent of the pitch angle.
Headroom is the height above the nosing of a tread to the ceiling above it.
Walkline for curved stairs, the inner radius of the curve may result in very narrow treads. The "walkline" is the imaginary line some distance away from the inner edge on which people are expected to walk. Building code will specify the distance. Building codes will then specify the minimum tread size at the walkline.
Wooden stairs at the shores of Lake Iso-Melkutin in Loppi, Finland
Stairs can take a large number of forms, combining winders and landings.
The simplest form is the straight flight of stairs, with neither winders nor landings. These types of stairs were commonly used in traditional homes as they are relatively easy to build and only need to be connected at the top and bottom; however, many modern properties may not choose straight flights of stairs because:
the upstairs is directly visible from the bottom of a straight flight of stairs.
it is potentially more dangerous in that a fall is not interrupted until the bottom of the stairs.
a straight flight requires enough space for the entire run of the stairs.[citation needed]
Another form of straight staircase is the space saver staircase, also known as paddle stairs or alternating tread staircases, that can be used for a steeper rise, but these can only be used in certain circumstances and must comply with regulations.
However, a basic straight flight of stairs is easier to design and construct than one with landings or winders. Although the rhythm of stepping is not interrupted in a straight run, which may offset the increased fall risk by helping to prevent a misstep in the first place, many stairs will require landings or winders to comply with safety standards in the Building Regulations.[11]
Straight stairs can have a mid-landing incorporated, but it is probably more common to see stairs that use a landing or winder to produce a bend in the stairs as a straight flight with a mid-landing will require a lot of linear space and is more commonly found in commercial buildings. "L" shaped stairways have one landing and usually change in direction by 90 degrees. "U" shaped stairs may employ a single wider landing for a change in direction of 180 degrees, or two landings for two changes in direction of 90 degrees each. A Z-shaped staircase incorporates two parallel 90 turns, creating a shape similar to that of the letter Z if seen from above. Use of landings and a possible change of direction have the following effects:
The upstairs is not directly visible from the bottom of the stairs, which can provide more privacy for the upper floor.
A fall can be halted at the landing point, reducing the distance someone would fall to reduce risks.
Though the landings consume total floor space, there is no requirement for a large single dimension, allowing more flexible floorplan designs.
For larger stairs, particularly in exterior applications, a landing can provide a place to rest the legs.
Other forms include stairs with winders that curve or bend at an acute angle, three flight stairs that join at a landing to form a T-shape, and stairs with balconies and complex designs can be produced to suit individual properties.
A mono string staircase is a term used for a steel spine staircase with treads.
A double string staircase has two steel beams on either side and treads in the center.
Spiral stairs, sometimes referred to in architectural descriptions as vice, wind around a newel (also the central pole). In Scottish architecture, they are commonly known as a turnpike stair. They typically have a handrail on the outer side only, and on the inner side just the central pole. A squared spiral stair assumes a square stairwell and expands the steps and railing to a square, resulting in unequal steps (larger where they extend into a corner of the square). A pure spiral assumes a circular stairwell and the steps and handrail are equal and positioned screw-symmetrically. A tight spiral stair with a central pole is very space efficient in the use of floor area.
Spiral stairs have the disadvantage of being very steep if they are tight or are otherwise not supported by a centre column, for two reasons:
The wider the spiral, the more steps can be accommodated per spiral. Therefore, if the spiral is large in diameter, via having a central support column that is strong (invariably large in diameter) and a special handrail that helps to distribute the load, each step may be longer and therefore the rise between each step may be smaller (equal to that of regular steps). Otherwise, the circumference of the circle at the walk line will be so small that it will be impossible to maintain a normal tread depth and a normal rise height without compromising headroom before reaching the upper floor.
To maintain headroom, some spiral stairs have very high rises to support a very short diameter. These are typically cases where the stairwell must be a small diameter by design or must not have any center support by design or may not have any perimeter support.
An example of perimeter support is the Vatican stairwell shown in the next section or the gothic stairwell shown to the left. That stairwell is only tight because of its design in which the diameter must be small. Many spirals, however, have sufficient width for normal size treads (8 inches) by being supported by any combination of a center pole, perimeter supports attaching to or beneath the treads, and a helical handrail. In this manner, the treads may be wide enough to accommodate low rises. In self-supporting stairs the spiral needs to be steep to allow the weight to distribute safely down the spiral in the most vertical manner possible. Spiral steps with centre columns or perimeter support do not have this limitation. Building codes may limit the use of spiral stairs to small areas or secondary usage if their treads are not sufficiently wide or have risers above nine and a half inches.[12]
The term "spiral" has a more narrow definition in a mathematical context, as a mathematical spiral lies in a single plane and moves towards or away from a central point. The mathematical term for motion where the locus remains at a fixed distance from a fixed line whilst moving in a circular motion about it is "helical". The presence or otherwise of a central pole does not affect the terminology applied to the design of the structure.
When used in Roman architecture spiral stairs were generally restricted to elite structures. They were then adopted into Christian ecclesiastic architecture.[13] There is a common misconception that spiral staircases in castles rose in a clockwise direction to hinder right-handed attackers.[14][15] While clockwise spiral staircases are more common in castles than anti-clockwise, they were even more common in medieval structures without a military role such as religious buildings.[16] Studies of spiral stairs in castle have concluded that "the role and position of spirals in castles ... had a much stronger domestic and status role than a military function"[16] and that "there are sufficient examples of anticlockwise stairs in Britain and France in [the 11th and 12th centuries] to indicate that the choice must have depended both on physical convenience and architectural practicalities and there was no military ideology that demanded clockwise staircases in the cause of fighting efficiency or advantage".[14]
Developments in manufacturing and design have led to the introduction of kit form spiral stairs. Steps and handrails can be bolted together to form a complete unit. These stairs can be made out of steel, timber, concrete or a combination of materials.
Helical or circular stairs do not have a central pole and there is a handrail on both sides. These have the advantage of a more uniform tread width when compared to the spiral staircase. Such stairs may also be built around an elliptical or oval planform.
Both double spiral and double helix staircases are possible, with two independent helical stairs in the same vertical space, allowing one person to ascend and another to descend, without ever meeting if they choose different helices. For examples, the Pozzo di S. Patrizio allows one-way traffic so that laden and unladen mules can ascend and descend without obstruction, while Chteau de Chambord, Chteau de Blois, and the Crdit Lyonnais headquarters ensure separation for social purposes. Fire escapes, though built with landings and straight runs of stairs, are often functionally double helices, with two separate stairs intertwined and occupying the same floor space. This is often in support of legal requirements to have two separate fire escapes.
Both spiral and helical stairs can be characterized by the number of turns that are made. A "quarter-turn" stair deposits the person facing 90 degrees from the starting orientation. Likewise, there are half-turn, three-quarters-turn and full-turn stairs. A continuous spiral may make many turns depending on the height. Very tall multi-turn spiral staircases are usually found in old stone towers within fortifications, churches and in lighthouses.
Winders may be used in combination with straight stairs to turn the direction of the stairs. This allows for a large number of permutations.
An alternating tread stair (center) between a half-width stair (left) and full-width stair (right), built with Duplo blocks.
Where there is insufficient space for the full run length of normal stairs, alternating tread stairs may be used. Alternating tread stairs allow for a safe forward-facing descent of very steep stairs. The treads are designed such that they alternate between treads for each foot: one step is wide on the left side; the next step is wide on the right side. There is insufficient space on the narrow portion of the step for the other foot to stand, hence the person must always use the correct foot on the correct step. The slope of alternating tread stairs can be as high as 65 degrees as opposed to standard stairs, which are almost always less than 45 degrees. The advantage of alternating tread stairs is that people can descend face forward. The only other alternative in such short spaces would be a ladder which requires backward-facing descent. Alternating tread stairs may not be safe for small children, the elderly or the physically challenged. Building codes typically classify them as ladders and will only allow them where ladders are allowed, usually basement or attic utility or storage areas not frequently accessed.
The image on the right illustrates the space efficiency gained by an alternating tread stair. The alternating tread stair appears in the image's center, with green-colored treads. The alternating stair requires one unit of space per step: the same as the half-width step on its left, and half as much as the full-width stair on its right. Thus, the horizontal distance between steps is in this case reduced by a factor of two, reducing the size of each step.
The horizontal distance between steps is reduced by a factor less than two if for construction reasons there are narrow "unused" steps.
There is often (here also) glide plane symmetry: the mirror image with respect to the vertical center plane corresponds to a shift by one step.
Alternating tread stairs have been in use since at least 1888.[17]
On a rarely used staircase from before 1754, the Crown Princess of Sweden ascends from the Stockholm Palace garden with her husband and baby in 2013.
Staircase - Ergonomically and for safety reasons, stairs must have certain measurements so that people can comfortably use them. Building codes typically specify certain measurements so that the stairs are not too steep or narrow.
Ergonomically and for safety reasons, stairs must have certain measurements so that people can comfortably use them. Building codes typically specify certain measurements so that the stairs are not too steep or narrow.
Nicolas-Franois Blondel in the last volume of his Cours d'architecture[18] (16751683) was the first known person to establish the ergonomic relationship of tread and riser dimensions.[19] He specified that 2 x riser + tread = step length.[20]
It is estimated that a noticeable mis-step occurs once in 7,398 uses and a minor accident on a flight of stairs occurs once in 63,000 uses.[21] Stairs can be a hazardous obstacle for some, so some people choose to live in residences without stairs so that they are protected from injury.[22]
Stairs are not suitable for wheelchairs and other vehicles. A stairlift is a mechanical device for lifting wheelchairs up and down stairs. For sufficiently wide stairs, a rail is mounted to the treads of the stairs, or attached to the wall. A chair is attached to the rail and the person on the chair is lifted as the chair moves along the rail.
(overview of Approved document K Stairs, Ladders and Ramps)[23]
The 2013 edition "approved document K" categorises stairs as private, utility and general access
When considering stairs for private dwellings all the specified measurements are in millimetres.
Building regulations are required for stairs used where the difference of level is greater than 600
Steepness of stairs rise and going - Any rise between 150 and 220 used with any going between 220 and 300
Any rise between 150 and 220 used with any going between 220 and 300
Maximum rise 220 and minimum going 220 remembering that the maximum pitch of private stairs is 42. The normal relationship between dimensions of the rise and going is that twice the rise plus the going (2R + G) should be between 550 and 700
Construction of steps - Steps should have level treads, they may have open risers but if so treads should overlap at least 16mm. Domestic private stairs are likely to be used by children under 5 years old so the handrail ballister spacing should be constructed so that a 100mm diameter sphere cannot pass through the opening in the risers in order to prevent children from sticking their heads through them and potentially getting stuck.
Steps should have level treads, they may have open risers but if so treads should overlap at least 16mm. Domestic private stairs are likely to be used by children under 5 years old so the handrail ballister spacing should be constructed so that a 100mm diameter sphere cannot pass through the opening in the risers in order to prevent children from sticking their heads through them and potentially getting stuck.
Headroom - A headroom of 2000mm is adequate. Special considerations can be made for loft conversions.
A headroom of 2000mm is adequate. Special considerations can be made for loft conversions.
Width of flights - No recommendations are given for stair widths.
No recommendations are given for stair widths. - Length of flights
Length of flights - The approved document refers to 16 risers (steps) for utility stairs and 12 for general access. There is no requirement for private stairs. In practice there will be fewer than 16 steps as 16 x 220 gives over 3500 total rise (storey height) which is way above that in a domestic situation.
The approved document refers to 16 risers (steps) for utility stairs and 12 for general access. There is no requirement for private stairs. In practice there will be fewer than 16 steps as 16 x 220 gives over 3500 total rise (storey height) which is way above that in a domestic situation.
Landings - Level, unobstructed landings should be provided at the top and bottom of every flight. The width and length being at least that of the width of the stairs and can include part of the floor. A door may swing across the landing at the bottom of the flight but must leave a clear space of at least 400 across the whole landing
Level, unobstructed landings should be provided at the top and bottom of every flight. The width and length being at least that of the width of the stairs and can include part of the floor. A door may swing across the landing at the bottom of the flight but must leave a clear space of at least 400 across the whole landing
Tapered steps - There are special rules for stairs with tapered steps as shown in the image Example of Winder Stairs above
There are special rules for stairs with tapered steps as shown in the image Example of Winder Stairs above
Alternate tread stairs can be provide in space saving situations
Guarding - Flights and landings must be guarded at the sides where the drop is more than 600mm. As domestic private stairs are likely to be used by children under 5 the guarding must be constructed so that a 100mm diameter sphere cannot pass through any opening or constructed so that children will not be able to climb the guarding. The height for internal private stairs should be at least 900 mm (35.4 in) and be able to withstand a horizontal force of 0.36|kN/m|.
Flights and landings must be guarded at the sides where the drop is more than 600mm. As domestic private stairs are likely to be used by children under 5 the guarding must be constructed so that a 100mm diameter sphere cannot pass through any opening or constructed so that children will not be able to climb the guarding. The height for internal private stairs should be at least 900 mm (35.4 in) and be able to withstand a horizontal force of 0.36|kN/m|.
American building codes, while varying from State to State and County to County, generally specify the following parameters:[24][25][26]
Minimum tread length, typically 9 inches (229 mm) excluding the nosing for private residences. Some building codes also specify a minimum riser height, often 5 inches (127 mm).[27]
Riser-Tread formula: Sometimes the stair parameters will be something like riser plus tread equals 1718 inches (432457 mm);[28] another formula is 2 times riser + tread equals 24.6 inches (625 mm), the length of a stride.[10] Thus a 7 inches (178 mm) rise and a 10.6 inches (269 mm) tread exactly meets this code. If only a 2 inches (51 mm) rise is used then a 20.6 inches (523 mm) tread is required. This is based on the principle that a low rise is more like walking up a gentle incline and so the natural swing of the leg will be longer.
Low rise stairs are very expensive in terms of the space consumed. Such low rise stairs were built into the Winchester Mystery House to accommodate the infirmities of the owner, Sarah Winchester, before the invention of the elevator. These stairways, called "Easy Risers" consist of five flights wrapped into a multi-turn arrangement with a total width equal to more than four times the individual flight width and a depth roughly equal to one flight's run plus this width. The flights have varying numbers of steps.
Slope: A value for the rise-to-tread ratio of 17/29 0.59 is considered optimal;[10] this corresponds to a pitch angle of about 30.
Variance on riser height and tread depth between steps on the same flight should be very low. Building codes require variances no larger than 0.1875 inches (4.76 mm) between depth of adjacent treads or the height of adjacent risers; within a flight, the tolerance between the largest and smallest riser or between the largest and smallest tread can not exceed 0.375 inches (9.5 mm).[29] The reason is that on a continuous flight of stairs, people get used to a regular step and may trip if there is a step that is different, especially at night. The general rule is that all steps on the same flight must be identical. Hence, stairs are typically custom made to fit the particular floor to floor height and horizontal space available. Special care must be taken on the first and last risers. Stairs must be supported directly by the subfloor. If thick flooring (e.g. thick hardwood planks) are added on top of the subfloor, it will cover part of the first riser, reducing the effective height of the first step. Likewise at the top step, if the top riser simply reaches the subfloor and thick flooring is added, the last rise at the top may be higher than the last riser. The first and last riser heights of the rough stairs are modified to adjust for the addition of the finished floor.
Maximum nosing protrusion, typically 1.25 inches (32 mm) to prevent people from tripping on the nosing.
Height of the handrail. This is typically between 34 and 38 inches (864 and 965 mm), measured to the nose of the tread. The minimum height of the handrail for landings may be different and is typically 36 inches (914 mm).
Handrail diameter. The size has to be comfortable for grasping and is typically between 1.25 and 2.675 inches (31.8 and 67.9 mm).
Maximum space between the balusters of the handrail. This is typically 4 inches (102 mm).
Openings (if they exist) between the bottom rail and treads are typically no bigger than 6 inches (152 mm).
Maximum vertical height between floors or landings. This allows people to rest and limits the height of a fall.
Mandate handrails if there is more than a certain number of steps (typically 2 risers)
Minimum width of the stairway, with and without handrails
Not allow doors to swing over steps; the arc of doors must be completely on the landing/floor.
The American Disabilities Act and other accessibility standards by state, such as Architectural Barriers Texas Accessibility Standards (TAS),[30] do not allow open risers on accessible or egress stairs.[31]
A staircase in Aarhus City Hall, Denmark. The dark grey, kidney-shaped capstone seen at the bottom of the stairwell contains the three foundation stones of the building and was used as the reference point for height adjustment during the entire building period
This section may need to be rewritten to comply with Wikipedia's quality standards, as it does not describe the topic of the section meaningfully. You can help. The talk page may contain suggestions. (June 2021)
As much as stairs are very functional, stairs can be very decorative and an impressive part of a building. Especially at the entrance of a large building stairs play an important role in the first impression of a building. In large buildings such as banks this is very popular. Modern companies and construction utilize the opportunities of functional stairs to actually upgrade buildings. Large utilities such as banks as well as residential buildings such as penthouses (e.g. in St George Wharf Tower) have modern and luxurious installations.
The world's longest stairway at the Niesenbahn funicular in Switzerland has 11,674 steps
The longest stairway is listed by Guinness Book of Records as the service stairway for the Niesenbahn funicular railway near Spiez, Switzerland, with 11,674 steps and a height of 1,669 m (5,476 ft).[32] The stairs are usually employee-only, but there is a public run called "Niesenlauf" once a year.
Mount Girnar, one of the holiest of sacred places for Hindu, Jain, and Buddhist followers, and also for some Muslims, is located in Junagadh district in the Indian state of Gujarat in Saurashtrian peninsula. At a height of 1100 metres, with five summits, each adorned with several sacred places, it is accessed on foot by soaring close to 10,000 steps along a rugged terrain and deciduous forest that is also the last home for Asiatic lions. It is the longest completely stone-made stairway in the world.
A flight of 7,200 steps (including inner temple Steps), with 6,293 Official Mountain Walkway Steps, leads up the East Peak of Mount Tai in China.
The Gemonian stairs were infamous as a place of execution during the early Roman Empire, especially during the period postdating Tiberius.[33]
The Haiku Stairs, on the island of Oahu, Hawaii, are approximately 4,000 steps which climb nearly 12 mile (0.8 km). Originally used to access longwire radio radio antennas which were strung high above the Haiku Valley, between Honolulu and Kaneohe, they are closed to hikers.
The Flrli stairs, in Lysefjorden, Norway, have 4,444 wooden steps which climb from sea level to 740 metres (2,428 feet). It is a maintenance stairway for the water pipeline to the old Flrli hydro plant. The hydro plant is now closed down, and the stairs are open to the public. The stairway is claimed to be the longest wooden stairway in the world.[34]
The CN Tower's staircase reaches the main deck level after 1,776 steps and the Sky Pod above after 2,579 steps; it is the tallest metal staircase on Earth.
The World Trade Center Survivors' Staircase is the last visible structure above ground level at the World Trade Center site. It was originally two outdoor flights of granite-clad stairs and an escalator that connected Vesey Street to the World Trade Center's Austin J. Tobin Plaza. During the September 11, 2001, attacks, the stairs served as an escape route for hundreds of evacuees from 5 World Trade Center, a 9-floor building adjacent to the 110-story towers.
Stairwell A was the lone stairway left intact after the second plane hit the South Tower of the World Trade Center during the September 11 attacks. It was believed to have remained intact until the South Tower collapsed at 9:59 am. 14 people were able to escape the floors located at the impact zone (including one man who saw the plane coming at him), and 4 people from the floors above the impact zone. Numerous 911 operators who received calls from individuals inside the South Tower were not well informed of the situation as it rapidly unfolded in the South Tower. Many operators told callers not to descend the tower on their own, even though it is now believed that Stairwell A was most likely passable at and above the point of impact.[36]
In London, England, a notable staircase is that to The Monument to the Great Fire of London, more commonly known simply as "the Monument". This is a column in the City of London, near the northern end of London Bridge, which commemorates the Great Fire of London. The top of the Monument is reached by a narrow winding staircase of 311 steps. Constructed between 1671 and 1677, it is the tallest isolated stone column in the world.[37]
The Loretto Chapel in Santa Fe, New Mexico is well known for its helix-shaped spiral staircase, which has been nicknamed "Miraculous Stair". It has been the subject of legend and rumor, and the circumstances surrounding its construction and its builder are considered miraculous by the Sisters of Loretto and many visitors.
An early kind of burglar alarm - trip stairs. The idea was that the unexpected change in the level of the stairs would foil the would-be robbers by causing them to trip in the darkness and wake someone.
^ a b c R.E. Putnam and G.E. Carlson, Architectural and Building Trades Dictionary, Third Edition, American Technical Publishers, Inc., 1974, ISBN 0-8269-0402-5
^ James H. Monckton (1891). Moncktons One Plane Method Of Hand Railing and Stair Building, Copyright 1888. John Wiley & Sons. p. Plate 2, Figure 4.
^ Section 3231(c) of the State of California Building Code specifies a rise between 4 and 7.5 inches (100 and 190 mm) and a minimum run of 10 inches (250 mm).
^ NFPA 101 Life Safety Code Handbook Tenth Edition 2006, Cot and Harrington, ISBN 0-87765-697-5, pg.167
Sunken Rooms: Design Challenge or Buried Treasure?
By Freshome Team - August 21, 2020 | 4 min read
August 21, 2020 | 4 min read - Sunken rooms where a living space is a few steps below the rest of the home can be traced back to the 1920s. Still, the style didnt really hit the mainstream until the swinging 60s. It was then that sunken rooms, or conversation pits, were the envy of everyone on the block. Created as a way to introduce a feeling of intimacy to homes, these sunken living areas pushed families and guests into one small and cozy space.
Sunken rooms - where a living space is a few steps below the rest of the home can be traced back to the 1920s. Still, the style didnt really hit the mainstream until the swinging 60s. It was then that sunken rooms, or conversation pits, were the envy of everyone on the block. Created as a way to introduce a feeling of intimacy to homes, these sunken living areas pushed families and guests into one small and cozy space.
While sunken rooms arent as popular today, there has been a resurgence of the style. You might have inherited a sunken room when you purchased your home. Or youre looking for a unique design feature in your new place. Either way, it might be time to start thinking of sunken rooms differently. With the right design and decor, your sunken room might just become your favorite spot in your home.
Sunken room pros - Sunken rooms can create conversation. Image: sirtravelalot/Shutterstock
Sunken rooms can create conversation. Image: sirtravelalot/Shutterstock
Theres a reason sunken living rooms were so wildly popular in the 60s and 70s. In an era where social events took place in the home, sunken rooms were the perfect way to make a home feel more intimate. Even if youre not planning on throwing a party at your place, sunken spaces definitely have their advantages.
They define the space. Sunken spaces are great for large, open concept homes. When walls are few, having rooms on a lower level clearly delineates the space without destroying any sight lines. The feeling of openness is preserved without losing any definition between, say, the living room and the kitchen.
They create intimacy. Cozy sunken rooms that are outfitted with comfortable seating and pillows are a great way to introduce a more intimate space in your home. Whether you use it for conversation or board games, it pushes the members of your family into a smaller space for a cozier vibe.
They introduce character. Sunken spaces give homes more character when compared to a flat, box-like floorplan. Some homes even feature circular sunken spaces and interesting woodwork to call attention to the detail.
They can make a room feel more spacious. Sunken rooms increase the distance between the floor and ceiling, which can make the space feel incredibly open. The added space between floor and ceiling makes a room look bigger. Installing a skylight or interesting lighting fixture above the sunken room can also draw the eye up.
Sunken room cons - Sunken rooms can create conversation. Image: sirtravelalot/Shutterstock
Sunken rooms can create conversation. Image: sirtravelalot/Shutterstock
Okay, so its not all peace, love and sunken spaces. There are a few drawbacks to take into consideration, especially if youre thinking about designing a sunken room in your own home.
They can cause accidents. If you asked most people what they disliked about their sunken rooms, chances are that the biggest complaint would simply be that theyre cumbersome. If youre not expecting a couple of stairs leading into a room, theres a risk of tripping and falling. It might seem like no big deal, but if youre living with someone who has accessibility issues, sunken rooms could be dangerous.
They dont offer much flexibility. Lets face it: if you have a sunken room, theres not a lot you can do with it. Sure, you can repurpose a room for lounging or swap it out for a playroom, but youre limited to working with a sometimes odd space for layouts. Even if you get creative with how you use the space, it always remains in the same place and youre always limited by the size and shape.
They arent open concept. If youre craving an open concept home, sunken rooms can disrupt those dreams. Because they define spaces so decisively, sunken rooms arent really considered elements in an open concept design.
Working with sunken rooms - Use color to denote indoor stairs. Image: pics721/Shutterstock
Use color to denote indoor stairs. Image: pics721/Shutterstock
Already have a home that features a sunken room? There are definitely ways to make it flow with the rest of your layout. Try these tips to make sure your sunken room is as safe as it is stylish.
Take precautions. Remember that visitors wont be as used to the sunken space as someone who lives in your home. Install handrails or use materials to make sure the steps are clearly marked. You can use different flooring for the stairs, for instance. Or you can paint the stairs so theyre easy to see and dont blend in with the rest of the floor.
Use the right furniture. Make sunken spaces look more purposeful and less awkward by filling them with furniture. Using the right scale for couches, tables and pillows gives the sunken space a clear purpose: lounging. Filling it with toy storage and activity centers makes it clear that its meant for kids. No matter how you use your sunken space, filling it with pieces gets rid of awkward angles.
Use color and light. Sunken rooms especially those in older homes can sometimes seem dark and unwelcoming. Utilize light and color to make the space more inviting. Incorporate the same colors in the sunken room as you do in the rest of your home. Match upholstery and furniture so the room is a cohesive part of your home design. And dont forget plenty of light: an interesting overhead fixture and plenty of accent lighting ensure your sunken room doesnt feel dark and dank.
Love em or hate em, sunken rooms will likely always be a part of American architecture and home design. Whether your home came with a sunken room or youre planning one as part of a new home, they can definitely be interesting and chic design features. With the right eye and a little love, a sunken room can truly become your very own buriedreasure.
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Thermal transmittance - Rate of transfer of heat through matter, expressed as a U-value
Rate of transfer of heat through matter, expressed as a U-value
Thermal transmittance is the rate of transfer of heat through matter. The thermal transmittance of a material (such as insulation or concrete) or an assembly (such as a wall or window) is expressed as a U-value.
Although the concept of U-value (or U-factor) is universal, U-values can be expressed in different units. In most countries, U-value is expressed in SI units, as watts per square metre-kelvin:
W/(m2K) - In the United States, U-value is expressed as British thermal units (Btu) per hour-square feet-degrees Fahrenheit:
In the United States, U-value is expressed as British thermal units (Btu) per hour-square feet-degrees Fahrenheit:
Btu/(hft2F) - Within this article, U-values are expressed in SI unless otherwise noted. To convert from SI to US customary values, divide by 5.678.[1]
Within this article, U-values are expressed in SI unless otherwise noted. To convert from SI to US customary values, divide by 5.678.[1]
Well-insulated parts of a building have a low thermal transmittance whereas poorly insulated parts of a building have a high thermal transmittance. Losses due to thermal radiation, thermal convection and thermal conduction are taken into account in the U-value. Although it has the same units as heat transfer coefficient, thermal transmittance is different in that the heat transfer coefficient is used to solely describe heat transfer in fluids while thermal transmittance is used to simplify an equation that has several different forms of thermal resistances.
It is described by the equation: - = A U (T1 - T2)
= A U (T1 - T2) - where is the heat transfer in watts, U is the thermal transmittance, T1 is the temperature on one side of the structure, T2 is the temperature on the other side of the structure and A is the area in square metres.
where is the heat transfer in watts, U is the thermal transmittance, T1 is the temperature on one side of the structure, T2 is the temperature on the other side of the structure and A is the area in square metres.
Thermal transmittances of most walls and roofs can be calculated using ISO 6946, unless there is metal bridging the insulation in which case it can be calculated using ISO 10211. For most ground floors it can be calculated using ISO 13370. For most windows the thermal transmittance can be calculated using ISO 10077 or ISO 15099. ISO 9869 describes how to measure the thermal transmittance of a structure experimentally. Choice of materials and quality of installation has a critical impact on the window insulation results. The frame and double sealing of the window system are the actual weak points in the window insulation.
Typical thermal transmittance values for common building structures are as follows:[citation needed]
In practice the thermal transmittance is strongly affected by the quality of workmanship and if insulation is fitted poorly, the thermal transmittance can be considerably higher than if insulation is fitted well[3]
When calculating a thermal transmittance it is helpful to consider the building's construction in terms of its different layers. For instance a cavity wall might be described as in the following table:
In this example the total resistance is 1.64 Km2/W. The thermal transmittance of the structure is the reciprocal of the total thermal resistance. The thermal transmittance of this structure is therefore 0.61 W/(m2K).
(Note that this example is simplified as it does not take into account any metal connectors, air gaps interrupting the insulation or mortar joints between the bricks and concrete blocks.)
It is possible to allow for mortar joints in calculating the thermal transmittance of a wall, as in the following table. Since the mortar joints allow heat to pass more easily than the light concrete blocks the mortar is said to "bridge" the light concrete blocks.
The average thermal resistance of the "bridged" layer depends upon the fraction of the area taken up by the mortar in comparison with the fraction of the area taken up by the light concrete blocks. To calculate thermal transmittance when there are "bridging" mortar joints it is necessary to calculate two quantities, known as Rmax and Rmin. Rmax can be thought of as the total thermal resistance obtained if it is assumed that there is no lateral flow of heat and Rmin can be thought of as the total thermal resistance obtained if it is assumed that there is no resistance to the lateral flow of heat. The U-value of the above construction is approximately equal to 2 / (Rmax + Rmin) Further information about how to deal with "bridging" is given in ISO 6946.
Schematic of ISO and ASTM compliant thermal transmittance measuring system.
Whilst calculation of thermal transmittance can readily be carried out with the help of software which is compliant with ISO 6946, a thermal transmittance calculation does not fully take workmanship into account and it does not allow for adventitious circulation of air between, through and around sections of insulation. To take the effects of workmanship-related factors fully into account it is necessary to carry out a thermal transmittance measurement.[4]
Example of measurement system for thermal transmittance according to ISO 9869 and ASTM C1155, model TRSYS.
ISO 9869 describes how to measure the thermal transmittance of a roof or a wall by using heat flux sensor. These heat flux meters usually consist of thermopiles which provide an electrical signal which is in direct proportion to the heat flux. Typically they might be about 100 mm (3.9 in) in diameter and perhaps about 5 mm (0.20 in) thick and they need to be fixed firmly to the roof or wall which is under test in order to ensure good thermal contact. When the heat flux is monitored over a sufficiently long time, the thermal transmittance can be calculated by dividing the average heat flux by the average difference in temperature between the inside and outside of the building. For most wall and roof constructions the heat flux meter needs to monitor heat flows (and internal and external temperatures) continuously for a period of 72 hours to be conform the ISO 9869 standards.
Generally, thermal transmittance measurements are most accurate when:
The difference in temperature between the inside and outside of the building is at least 5 C (9.0 F).
The weather is cloudy rather than sunny (this makes accurate measurement of temperature easier).
There is good thermal contact between the heat flux meter and the wall or roof being tested.
The monitoring of heat flow and temperatures is carried out over at least 72 hours.
Different spots on a building element are measured or a thermographic camera is used to secure the homogeneity of the building element.
When convection currents play a part in transmitting heat across a building component, then thermal transmittance increases as the temperature difference increases. For example, for an internal temperature of 20 C (68 F) and an external temperature of 20 C (4 F), the optimum gap between panes in a double glazed window will be smaller than the optimum gap for an external temperature of 0 C (32 F).
The inherent thermal transmittance of materials can also vary with temperaturethe mechanisms involved are complex, and the transmittance may increase or decrease as the temperature increases.[5]
^ Holladay, Martin. "Metric and Imperial". Green Building Advisor. Retrieved 25 March 2019.
^ Passivhaus Institute's thermal testing results for Rehau Geneo 'PHZ' triple glazed window [1]
^ Field investigations of the thermal performance (U-values) of construction elements as built [2]
Embodied Carbon: - Developing a Client Brief
Developing a Client Brief - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 3. Knowing how and what to ask for
3. Knowing how and what to ask for
4. Creating the brief Putting pen to paper
Derwent London - 2017 UK Green Building Council
2017 UK Green Building Council - Registered charity number 1135153
Registered charity number 1135153 - What does this guidance do?
What does this guidance do? - How to use this guide
How to use this guide - Why focus the guidance on clients?
Why focus the guidance on clients? - What is embodied carbon?
What is embodied carbon? - Why is it important?
Why is it important? - This document is produced for general
This document is produced for general - guidance only. How you choose to use
guidance only. How you choose to use - it is up to you. While the guidance has
it is up to you. While the guidance has
been produced in good faith it does - not constitute advice and UK-GBC and
not constitute advice and UK-GBC and - the authors of this guidance do not
the authors of this guidance do not - represent or warrant that the content
represent or warrant that the content - is suitable for your purposes, accurate,
is suitable for your purposes, accurate, - complete or up-to-date. UK-GBC and
complete or up-to-date. UK-GBC and - the authors exclude all liability whether
the authors exclude all liability whether - arising in contract, tort (including
arising in contract, tort (including - negligence) or otherwise, and will not
negligence) or otherwise, and will not - be liable to you for any direct, indirect
be liable to you for any direct, indirect
or consequential loss or damage, - arising in connection with your use of,
arising in connection with your use of, - or reliance on, the guidance.
or reliance on, the guidance. - Context, ambitions and aims
Context, ambitions and aims - Assessment boundary and reference study period
Assessment boundary and reference study period - Assessment scope
Assessment scope - Assessment standards and calculation methodology
Assessment standards and calculation methodology - Data and tools
Data and tools - Starting point, iterations and frequency
Starting point, iterations and frequency - Presenting the results
Presenting the results - 1. Overview
1. Overview - With the increasingly successful reduction of operational energy (and thus carbon emissions)
With the increasingly successful reduction of operational energy (and thus carbon emissions)
in the built environment, the industrys next challenge is to reduce the carbon intensity of the
structures themselves (embodied carbon). We know that clients will play a critical role in this
work as what clients ask for, the supply chain works to deliver. UK-GBC also understands that
embodied carbon is an area that many clients are just beginning to address.
This guide is designed for those who need to write effective briefs for commissioning their
first embodied carbon measurements, but who may be at an early stage of embodied carbon
knowledge. It is not a how-to guide for measuring carbon, or which method or tools should
be adopted. - This guide been written by the industry, for the industry. The guidance provides
This guide been written by the industry, for the industry. The guidance provides
straightforward information on how to develop a brief and get the job done. For those
looking for greater depth of knowledge, there is Supporting Guidance with links to further
detailed information. - Embodied Carbon: Developing a Client Brief has been led by a team at the UK-GBC,
Embodied Carbon: Developing a Client Brief has been led by a team at the UK-GBC,
supported by a specialist working group. At key points in the development process the guide
has gone to wider UK-GBC member review (primarily with clients). UK-GBC would like to
thank all those who have contributed to this new guide.
UK-GBCs vision is of a built environment that is fully decarbonised. This has to include both
embodied and operational carbon. As operational carbon reduces, the relative significance
of embodied carbon increases. So we will continue to advocate for embodied carbon to
become a mainstream issue in building design, construction and maintenance. Indeed, we
will be encouraging our client members and other clients in the industry to create their own
embodied carbon briefs by making effective use of this guidance.
Also, through our work with cities and other local and national authorities, we will be
encouraging the assessment of embodied carbon within the public sector planning and
procurement process. - Julie Hirigoyen
Julie Hirigoyen - CEO, UK Green Building Council
CEO, UK Green Building Council - AHMM | Camden Lock Village
AHMM | Camden Lock Village - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Introduction
Introduction - 2. Introduction
2. Introduction - 2.1 What does this guidance do?
2.1 What does this guidance do? - The purpose of this
The purpose of this - guide is to set out
guide is to set out - clear and practical
clear and practical - guidance to enable built
guidance to enable built - environment clients
environment clients - to start requesting
to start requesting - embodied carbon
embodied carbon - measurement.
measurement. - The purpose of this guide is to set out clear and
The purpose of this guide is to set out clear and
practical guidance to enable built environment clients - to begin requesting embodied carbon measurements.
to begin requesting embodied carbon measurements. - This includes understanding the outcomes from an
This includes understanding the outcomes from an - assessment and how to start acting on the results.
assessment and how to start acting on the results.
This guide has been produced in response to extensive
consultation. Feedback from the UK-GBC membership - indicates a difficulty in knowing exactly where and
indicates a difficulty in knowing exactly where and - how to start the process of measuring embodied
how to start the process of measuring embodied - carbon. Much guidance exists on embodied carbon
carbon. Much guidance exists on embodied carbon - measurement and this document aims to complement
measurement and this document aims to complement - it with a focus on the contractual demands that clients
it with a focus on the contractual demands that clients
place on their supply chains. - The intended audience is clients who are aware of
The intended audience is clients who are aware of
the importance of embodied carbon and want to - commission an embodied carbon measurement but
commission an embodied carbon measurement but - do not know where to start.
do not know where to start. - The guidance explains some of the basics of embodied
The guidance explains some of the basics of embodied
carbon, gives an overview of some suggested - approaches, provides example clauses to propel
approaches, provides example clauses to propel - embodied carbon requirements down the supply chain
embodied carbon requirements down the supply chain - and gives practical tips on how to use the outcomes
and gives practical tips on how to use the outcomes
of an assessment. The guidance is appropriate for any
capital investment intervention in the built environment - such as new build, refurbishment or renewal whether
such as new build, refurbishment or renewal whether
in buildings, infrastructure or other built assets. The
Supporting Guidance builds on the topics with a - greater level of detail.
greater level of detail. - The guidance does not, nor is it intended to, set out
The guidance does not, nor is it intended to, set out
a methodology or standard for embodied carbon - measurement, nor does it compare products or give
measurement, nor does it compare products or give
guidance on product level assessments. Rather, it
helps to set out a usable framework for clients to
begin to develop an approach to embodied carbon - measurement within their organisations. Also, this
measurement within their organisations. Also, this - guidance is not intended to diminish the need to
guidance is not intended to diminish the need to
address the operational carbon of assets in use.
Derwent London - 2|3
2|3 - 2.2 How to use this guide
2.2 How to use this guide - 1
1 - Throughout the document there are
Throughout the document there are - signposts which will direct readers to
signposts which will direct readers to - related sections of the guidance and
related sections of the guidance and - further information in the Glossary
further information in the Glossary - and Supporting Guidance.
and Supporting Guidance. - Overview
Overview - Signpost to relevant
Signpost to relevant - section
section - 2
2 - Introduction
Introduction - to Supporting
to Supporting - 66 Signpost
66 Signpost - Guidance
Guidance - E
E - WH RE
WH RE - WHO
WHO - WHEN
WHEN - Explains the key
Explains the key - considerations when writing
considerations when writing - an embodied carbon brief
an embodied carbon brief - HOW
HOW - Readers will benefit from
Readers will benefit from - downloading this document and
downloading this document and - reading using Adobe Acrobat.
reading using Adobe Acrobat. - 3
3 - Knowing how
Knowing how - and what
and what - to ask for
to ask for - WHAT
WHAT - WHY
WHY - Provides example wording for
Provides example wording for - all the key considerations
all the key considerations - explained in Section 3
explained in Section 3 - 4
4 - Creating
Creating - the brief
the brief - Brings together a
Brings together a - selection of the example
selection of the example - wording from Section 4
wording from Section 4 - into one example brief
into one example brief - The term brief is used to refer
The term brief is used to refer - to any document used in the
to any document used in the - commissioning of embodied
commissioning of embodied - carbon assessments.
carbon assessments. - 5
5 - EMBODIED
EMBODIED - CARBON BRIEF
CARBON BRIEF - Example
Example - Brief
Brief - 6
6 - What to do
What to do - with the
with the - outputs
outputs - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 2.3 Why focus the guidance on
2.3 Why focus the guidance on - clients?
clients? - Construction projects are initiated by clients.
Construction projects are initiated by clients. - Clients are usually the instigators of projects
Clients are usually the instigators of projects - sustainability agenda. As part of this, clients may
sustainability agenda. As part of this, clients may
set out a requirement to measure embodied - carbon. Thus, by increasing awareness and action
carbon. Thus, by increasing awareness and action
on embodied carbon at the client level, it will be
introduced to the industry as the supply chain - responds to clients requests.
responds to clients requests. - This guidance has been developed in
This guidance has been developed in - collaboration with UK-GBC members, with a
collaboration with UK-GBC members, with a - particular focus on clients. Members from the
particular focus on clients. Members from the - client side and the supply chain have contributed
client side and the supply chain have contributed - content and provided feedback.
content and provided feedback. - The following groups were identified as being
The following groups were identified as being - clients and form the primary audience:
clients and form the primary audience: - investors (pension funds, private equity
investors (pension funds, private equity - funds etc.)
funds etc.) - REITs (real estate investment trusts)
REITs (real estate investment trusts) - developer-landlords
developer-landlords - owner occupiers and tenants
owner occupiers and tenants - local authorities
local authorities - infrastructure clients
infrastructure clients - Embodied carbon is the total
Embodied carbon is the total - greenhouse gas (GHG) emissions
greenhouse gas (GHG) emissions - generated to produce a built asset.
generated to produce a built asset. - This includes emissions caused by
This includes emissions caused by - extraction, manufacture/processing,
extraction, manufacture/processing, - transportation and assembly of every
transportation and assembly of every - product and element in the asset.
product and element in the asset. - Introduction
Introduction - 2.4 What is embodied carbon?
2.4 What is embodied carbon? - 2.5 Why is it important?
2.5 Why is it important? - Embodied carbon is the total greenhouse
Embodied carbon is the total greenhouse - gas (GHG) emissions (often simplified to
gas (GHG) emissions (often simplified to
carbon) generated to produce a built asset.
This includes emissions caused by extraction, - manufacture/processing, transportation and
manufacture/processing, transportation and - assembly of every product and element
assembly of every product and element - in an asset. In some cases, (depending on
in an asset. In some cases, (depending on
the boundary of an assessment), it may
also include the maintenance, replacement, - deconstruction, disposal and end-of-life
deconstruction, disposal and end-of-life - aspects of the materials and systems that
aspects of the materials and systems that - make up the asset. It excludes operational
make up the asset. It excludes operational - emissions of the asset.
emissions of the asset. - 2.5.1 High level context
2.5.1 High level context - Some of the other commonly used definitions
Some of the other commonly used definitions - within the built environment sector include:
within the built environment sector include: - Carbon emissions associated with energy
Carbon emissions associated with energy - consumption (embodied energy) and chemical
consumption (embodied energy) and chemical - processes during the extraction, manufacture,
processes during the extraction, manufacture, - transportation, assembly, replacement and
transportation, assembly, replacement and - deconstruction of construction materials or
deconstruction of construction materials or - products.[1]
products.[1] - The carbon dioxide emissions associated with
The carbon dioxide emissions associated with - making a building as distinct from using it
making a building as distinct from using it - are referred to as embodied carbon. More
are referred to as embodied carbon. More - precisely, embodied carbon covers greenhouse
precisely, embodied carbon covers greenhouse - gas (GHG) emissions that arise from the energy
gas (GHG) emissions that arise from the energy
and industrial processes used in the processing, - manufacture and delivery of the materials,
manufacture and delivery of the materials, - products and components required to construct a
products and components required to construct a - building.[2]
building.[2] - "Embodied carbon, sometimes referred to as
"Embodied carbon, sometimes referred to as - capital carbon, refers to the emissions associated
capital carbon, refers to the emissions associated - with the creation of an asset. Capital carbon
with the creation of an asset. Capital carbon
is being adopted in the infrastructure sector - because it accords with the concept of capital
because it accords with the concept of capital - cost"[3]
cost"[3] - In terms of the Greenhouse Gas (GHG) Protocol
In terms of the Greenhouse Gas (GHG) Protocol
for emissions accounting, the embodied carbon - of built assets is included within Scope 3
of built assets is included within Scope 3 - emissions.[4]
emissions.[4] - 4|5
4|5 - Embodied
Embodied - carbon
carbon - 22%
22% - At a global level, buildings account for 32% of
At a global level, buildings account for 32% of
energy use and 30% of energy-based GHG - emissions. These emissions will continue to
emissions. These emissions will continue to - rise under a business-as-usual scenario.[5] The
rise under a business-as-usual scenario.[5] The
embodied carbon impacts and the impacts of - other built asset types are not accounted for,
other built asset types are not accounted for,
which makes the impact of the whole built - environment larger. To play its part in limiting
environment larger. To play its part in limiting
global temperature increase to 2C, the built - environment sector must reduce its emissions by
environment sector must reduce its emissions by - a total of 84 GtCO2 by 2050.[5]
a total of 84 GtCO2 by 2050.[5]
As part of the Paris Agreement, member - states will have to transition to net zero-carbon
states will have to transition to net zero-carbon - economies.[6] So far, 91 countries have included
economies.[6] So far, 91 countries have included
elements of commitments relating to buildings - in their Nationally Determined Contributions
in their Nationally Determined Contributions - (NDCs) (these are the national declarations of
(NDCs) (these are the national declarations of
commitment). - In the UK, the Low Carbon Routemap[7] and the
In the UK, the Low Carbon Routemap[7] and the
2015 Routemap Progress Report highlight that - the sector needs to find a further 39% reduction
the sector needs to find a further 39% reduction
in carbon emissions[8] from the 1990 baseline in
order to meet the Governments target to reduce - carbon emissions in the built environment by
carbon emissions in the built environment by - 50% by 2025[9]. Longer term, deeper reductions
50% by 2025[9]. Longer term, deeper reductions
will be needed to reach the UKs Climate Change
Act target of 80% reduction by 2050 from a 1990
baseline. - Consideration of embodied carbon within
Consideration of embodied carbon within - the built environment at the initial design
the built environment at the initial design - and construction stages, especially by the
and construction stages, especially by the - construction and property sectors, is necessary
construction and property sectors, is necessary - in order to achieve the required GHG reductions
in order to achieve the required GHG reductions - (see Figure 1). The relative significance of
(see Figure 1). The relative significance of
embodied carbon is increasing, as both the grid
decarbonises and operational emissions decrease - due to increased efficiency (see Figure 1).
due to increased efficiency (see Figure 1).
Operational - carbon
carbon - 78%
78% - 2012
2012 - Total annual built
Total annual built - environment emissions
environment emissions - 202MtCO2e
202MtCO2e - Operational
Operational - carbon
carbon - 66%
66% - Embodied
Embodied - carbon
carbon - 34%
34% - 2025
2025 - 113MtCO2e
113MtCO2e - Embodied
Embodied - carbon
carbon - 40%
40% - Operational
Operational - carbon
carbon - 60%
60% - 2050
2050 - 45MtCO2e
45MtCO2e - Embodied
Embodied - Operational
Operational - Domestic
Domestic - Domestic
Domestic - Non-domestic
Non-domestic - Non-domestic
Non-domestic - Infrastructure
Infrastructure - Infrastructure
Infrastructure - Figure 1 Increasing significance of embodied
Figure 1 Increasing significance of embodied - carbon (in 80% emissions reduction scenario)[10]
carbon (in 80% emissions reduction scenario)[10]
Walsh | St John Bosco College - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Introduction
Introduction - Embodied carbon has been recognised in infrastructure
Embodied carbon has been recognised in infrastructure - with regulation in specific sectors. For example, in
with regulation in specific sectors. For example, in
the rail industry, the High Level Output Specification
(HLOS) requires consideration of traction and - no-traction carbon emissions from railway activities.
no-traction carbon emissions from railway activities. - Similarly, Ofwat[11] required all water companies to
Similarly, Ofwat[11] required all water companies to
produce a capital and operational carbon footprint - of their proposed 2010-2015 asset investment and
of their proposed 2010-2015 asset investment and - management programme.[12]
management programme.[12] - At an organisational level, industry standards such as
At an organisational level, industry standards such as
PAS 2080:2016 Carbon management in infrastructure - are encouraging all companies to begin effectively
are encouraging all companies to begin effectively - managing their carbon footprints, with a strong
managing their carbon footprints, with a strong - emphasis on embodied carbon.
emphasis on embodied carbon. - 2.5.2 Why is it important to a client
2.5.2 Why is it important to a client
organisation? - There are now a variety of reasons, beyond the
There are now a variety of reasons, beyond the
environmental, motivating client organisations - to measure their embodied carbon impact. The
to measure their embodied carbon impact. The - embodied carbon impact at an asset level is more
embodied carbon impact at an asset level is more
significant than has been previously thought. - Recent figures show that over a 30-year period,
Recent figures show that over a 30-year period,
embodied emissions account for more than 50% - of the total carbon emitted for some building
of the total carbon emitted for some building - types. Consequently, addressing embodied carbon
types. Consequently, addressing embodied carbon - is a critical part of reducing a clients overall carbon
is a critical part of reducing a clients overall carbon
impact. See (Figure 2). - The aim of this guidance is to help all built
The aim of this guidance is to help all built
environment clients to start effectively measuring - embodied carbon.
embodied carbon. - Commercial and Operational
Commercial and Operational - The economic case for considering embodied carbon
The economic case for considering embodied carbon - has been outlined in other industry research. The
has been outlined in other industry research. The
findings include: - Relatively low cost when compared to many
Relatively low cost when compared to many - operational carbon saving solutions;
operational carbon saving solutions; - Encourages lean design and drives resource
Encourages lean design and drives resource - efficiency;
efficiency; - Unlocks innovation, provides competitive
Unlocks innovation, provides competitive - advantage and export potential;
advantage and export potential; - Gives further insight into GHG risks and
Gives further insight into GHG risks and - opportunities;
opportunities; - 6|7
6|7 - Additionally, industry agreements and schemes
Additionally, industry agreements and schemes - are increasingly referring to embodied carbon
are increasingly referring to embodied carbon - as it demonstrates an organisations improved
as it demonstrates an organisations improved - understanding of carbon in built assets. For example:
understanding of carbon in built assets. For example:
Clients signing up to Science Based Targets take - a progressive approach to the measurement and
a progressive approach to the measurement and - reduction of all carbon emissions[14]; and
reduction of all carbon emissions[14]; and
Companies opting to sign up to the RE100 are
bringing embodied carbon emissions into stark - contrast against annual operating emissions.
contrast against annual operating emissions. - Additionally, some planning authorities are beginning
Additionally, some planning authorities are beginning - to acknowledge embodied carbon.
to acknowledge embodied carbon. - Can be a helpful tool for clients to compare assets,
Can be a helpful tool for clients to compare assets,
dependent on a common assessment framework, - demonstrating embodied carbon improvement
demonstrating embodied carbon improvement - over time; and
over time; and - Can assist in achieving credits in some building
Can assist in achieving credits in some building - assessment sustainability rating schemes.
assessment sustainability rating schemes. - Supermarket
Supermarket - Office
Office - Product
Product - Construction
Construction - Operational water and energy
Operational water and energy - Maintenance, repairs
Maintenance, repairs - End of life
End of life - Westgate Alliance | Westgate Oxford Alliance
Westgate Alliance | Westgate Oxford Alliance - Semi-detached house
Semi-detached house - Warehouse
Warehouse - Figure 2 Relative impact of the consequent life cycle stages
Figure 2 Relative impact of the consequent life cycle stages
on the overall carbon footprint for different types of
buildings, calculated over 30 years (energy results have been
based on Building Regulations).[13] All but Operational water
and energy relate to embodied carbon - Industry agreements and schemes
Industry agreements and schemes - are increasingly referring to embodied
are increasingly referring to embodied - carbon as it demonstrates an
carbon as it demonstrates an - organisations improved understanding
organisations improved understanding - of carbon in built assets.
of carbon in built assets. - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Introduction
Introduction - Reputational
Reputational - Environmental
Environmental - Organisations are seeking to better understand and
Organisations are seeking to better understand and - manage what matters most to their stakeholders.[15]
manage what matters most to their stakeholders.[15]
An initial embodied carbon assessment can be - commissioned using a high level approach. As clients
commissioned using a high level approach. As clients
carry out more projects, they can build on their
embodied carbon knowledge and ask for more - information to a greater level of detail. Similarly,
information to a greater level of detail. Similarly,
investor rating and measurement indices are starting to - include assessment of embodied carbon. For example:
include assessment of embodied carbon. For example:
The environmental reasons for addressing carbon - are well documented. Some of the most compelling
are well documented. Some of the most compelling
reasons include: - The Dow Jones Sustainability Index (DJSI) now
The Dow Jones Sustainability Index (DJSI) now
includes a section about the life cycle assessment - of building materials;
of building materials; - The FTSE4Good Index asks questions on lifecycle
The FTSE4Good Index asks questions on lifecycle - studies and related carbon emissions reductions;
studies and related carbon emissions reductions; - Embodied carbon can form a key part of any
Embodied carbon can form a key part of any
corporate climate change strategy; - Addressing embodied carbon offers an attractive,
Addressing embodied carbon offers an attractive, - one-time opportunity to make a significant saving
one-time opportunity to make a significant saving - in a shorter period of time, whereas operational
in a shorter period of time, whereas operational
carbon savings unfold over a longer period of - time;[18]
time;[18] - Consideration of embodied carbon at design
Consideration of embodied carbon at design - stage can facilitate greater resource efficiency.
stage can facilitate greater resource efficiency. - The CDP includes voluntary reporting of Scope 3
The CDP includes voluntary reporting of Scope 3 - emissions;[16]
emissions;[16] - The GRESB survey has a significant volume
The GRESB survey has a significant volume - of questions on new construction and major
of questions on new construction and major - renovations.[17]
renovations.[17] - Reporting on Scope 1 and 2 GHG emissions has
Reporting on Scope 1 and 2 GHG emissions has
become more widespread in the built environment - in the past few years. A few companies have begun
in the past few years. A few companies have begun
to explore Scope 3 emissions measurement at an - organisational level, such as their employee travel.
organisational level, such as their employee travel.
Beyond this, only a small minority have begun to
measure Scope 3 emissions at an asset level. By
measuring and reporting embodied carbon, built - environment clients can take demonstrable action on
environment clients can take demonstrable action on - Scope 3 emissions.
Scope 3 emissions. - Walsh | Bankside
Walsh | Bankside - Embodied carbon forms an aspect
Embodied carbon forms an aspect - of many ESG (environmental,
of many ESG (environmental, - social and governance) analysts
social and governance) analysts - research reports, which are
research reports, which are - used to judge the quality of a
used to judge the quality of a - company/investment and its
company/investment and its - ability to manage its sustainability
ability to manage its sustainability - responsibilities.
responsibilities. - Land Securities | Nova Victoria
Land Securities | Nova Victoria - 8|9
8|9 - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Knowing how and what to ask for
Knowing how and what to ask for - 3. Knowing how and
3. Knowing how and - what to ask for
what to ask for - This guidance provides a structure for clients to begin building their
This guidance provides a structure for clients to begin building their
embodied carbon knowledge and move towards developing a brief
for their first embodied carbon assessment. - An initial embodied carbon assessment can be commissioned using
An initial embodied carbon assessment can be commissioned using
a high level approach. For example, an assessment of the high
intensity embodied carbon elements[19] e.g. the structural frame. As
clients carry out more projects, they can build on their embodied
carbon knowledge and ask for more information to a greater level of
detail in each assessment e.g. the fixtures and fittings.
10 | 11 - Decide where the main
Decide where the main - interaction points are for
interaction points are for - the project(s)
the project(s) - Decide when the
Decide when the - embodied carbon
embodied carbon - measurement process will
measurement process will - start, how many iterations
start, how many iterations - are required and their
are required and their - frequency.
frequency. - WHERE
WHERE - WHEN
WHEN - Clients can communicate their embodied carbon assessment
Clients can communicate their embodied carbon assessment - requirements more effectively by:
requirements more effectively by: - Decide who is responsible
Decide who is responsible - for each stage of the
for each stage of the - embodied carbon
embodied carbon - measurement process
measurement process - WHO
WHO - EMBODIED
EMBODIED - CARBON BRIEF
CARBON BRIEF - understanding the key considerations of an embodied carbon
understanding the key considerations of an embodied carbon - brief;
brief; - being aware of the variables within the assessment and how
being aware of the variables within the assessment and how
they impact the calculation; - understanding what decisions could be taken and the factors
understanding what decisions could be taken and the factors
that influence those decisions. - HOW
HOW - WHAT
WHAT - Figure 3 represents the key considerations of an embodied carbon
Figure 3 represents the key considerations of an embodied carbon
brief. Each key consideration has variables within it which can impact
on the final embodied carbon calculation. - It should be noted that there is no starting point for this process. By
It should be noted that there is no starting point for this process. By
exploring these key considerations simultaneously, clients will build
their knowledge base in order to write their first embodied carbon
brief. As such, the following sections can be read in any order.
WHY - Decide how to incorporate
Decide how to incorporate - embodied carbon through
embodied carbon through - existing in-house
existing in-house - documents.
documents. - Understand what the
Understand what the - embodied carbon brief
embodied carbon brief - should contain and what
should contain and what - decisions are needed for
decisions are needed for - each element.
each element. - Recognise the drivers for
Recognise the drivers for - the organisation to start to
the organisation to start to - measure embodied carbon
measure embodied carbon - and what the objectives of
and what the objectives of - the assessment are.
the assessment are. - Matt Chisnall
Matt Chisnall - Figure 3 The key considerations of an embodied carbon brief
Figure 3 The key considerations of an embodied carbon brief
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 3.1 Who?
3.1 Who? - Decide who is responsible
Decide who is responsible - for each stage of the
for each stage of the - embodied carbon
embodied carbon - measurement process
measurement process - WHO
WHO - 3.1.1 Who should
3.1.1 Who should - engage in the embodied carbon process?
engage in the embodied carbon process? - Clients can own the embodied carbon process to
Clients can own the embodied carbon process to - ensure that it remains a priority throughout the project.
ensure that it remains a priority throughout the project.
This can be achieved by assigning responsibility to one
person to deliver the embodied carbon assessment, - thereby ensuring a continued focus and awareness
thereby ensuring a continued focus and awareness - across the whole project team. This is especially
across the whole project team. This is especially
important when interacting with the design and - contractor teams who will be responding to the brief
contractor teams who will be responding to the brief
in terms of how decisions impact the measurement - and reduction of embodied carbon. In these cases,
and reduction of embodied carbon. In these cases,
it may be beneficial to use a common framework
which designates responsibilities to each party, such as
PAS 2080.[20] - Knowing how and what to ask for
Knowing how and what to ask for - 3.2 When?
3.2 When? - Decide when the
Decide when the - embodied carbon
embodied carbon - measurement process
measurement process - will start, how many
will start, how many - iterations are required
iterations are required - and their frequency
and their frequency - WHEN
WHEN - 3.2.1 Starting point, iterations and frequency
3.2.1 Starting point, iterations and frequency
The starting point for an assessment on a project
affects the level of impact that can be had on the
embodied carbon outcome. - Embodied carbon reduction is best tackled by
Embodied carbon reduction is best tackled by - measuring as early as possible during design so that
measuring as early as possible during design so that
reduction opportunities can be highlighted and acted - upon. Clients can outline the intent to measure and
upon. Clients can outline the intent to measure and
reduce embodied carbon before conceptual design - begins. This should ensure that the project team is
begins. This should ensure that the project team is
conscious of this intent during the design phase.
Section 6.3 Reducing embodied carbon - The greatest value can be derived when embodied
The greatest value can be derived when embodied - carbon assessments are treated as an iterative
carbon assessments are treated as an iterative - exercise rather than a one-off activity. Clients who
exercise rather than a one-off activity. Clients who
commission an early assessment at the conceptual - design stage may find it valuable to repeat the study
design stage may find it valuable to repeat the study
in order to compare the original design with both the
progressed design and the final as-built product.[21]
This comparison will reveal how the embodied carbon - impact has changed between the project stages.
impact has changed between the project stages. - Section 4.6 Starting point, iterations and
Section 4.6 Starting point, iterations and - frequency
frequency - 3.3 Where?
3.3 Where? - Decide where the main
Decide where the main - interaction points are for
interaction points are for - the project(s)
the project(s) - 12 | 13
12 | 13 - E
E - WH RE
WH RE - 3.3.1 Where are the
3.3.1 Where are the - decision points?
decision points? - Clients can assess where to engage in the project
Clients can assess where to engage in the project
according to where there are critical decision points - rather than specific actors, roles or responsibilities. As
rather than specific actors, roles or responsibilities. As
project teams move from one construction phase to - the next, more construction details are locked in
the next, more construction details are locked in
through the decisions made. These are the critical
decision points which also lock in embodied carbon.
Clients can review where these decision points are in
advance, ensure that any decisions are taken according
to the embodied carbon brief, and then capture data
as required. - These critical decision points also affect a clients
These critical decision points also affect a clients - commercial team. The design and material choices will
commercial team. The design and material choices will
affect layout and product specifications which, in turn,
affect aesthetics, comfort, durability and saleability.
Table 1 identifies major embodied carbon decisions - that can be taken at particular stages during the
that can be taken at particular stages during the
construction process. - 3.3.2 The impact of different project
3.3.2 The impact of different project - procurement routes
procurement routes - There are many different procurement processes that
There are many different procurement processes that - are used to commission a project. Different procurement
are used to commission a project. Different procurement
routes will use differing approaches to producing and - issuing tender information and communicating client
issuing tender information and communicating client - requirements. Therefore, it is important to discuss the
requirements. Therefore, it is important to discuss the
best route with the project management team to - ensure that the embodied carbon requirements are
ensure that the embodied carbon requirements are - understood and clearly set out.
understood and clearly set out. - In addition to setting out clear requirements, a clear
In addition to setting out clear requirements, a clear
line of responsibility should also be established to - ensure the assessment work is completed to the
ensure the assessment work is completed to the - level of detail specified. In many circumstances
level of detail specified. In many circumstances - this means clients (either themselves or via their
this means clients (either themselves or via their
project representatives) will instruct a third party - consultant to undertake an embodied carbon
consultant to undertake an embodied carbon - assessment. Sometimes in design and build contracts
assessment. Sometimes in design and build contracts - this responsibility will be passed directly to the
this responsibility will be passed directly to the - contractor, who in turn may employ a consultant to
contractor, who in turn may employ a consultant to
undertake the embodied carbon assessment. - Westgate Alliance | Westgate Oxford Alliance
Westgate Alliance | Westgate Oxford Alliance - Westgate Alliance | Westgate Oxford Alliance
Westgate Alliance | Westgate Oxford Alliance - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Knowing how and what to ask for
Knowing how and what to ask for - 3.4 How?
3.4 How? - Table 1 Embodied carbon and work stages
Table 1 Embodied carbon and work stages - Project
Project - stages
stages - Brief
Brief - Design
Design - Build
Build - Embodied Carbon actions and processes
Embodied Carbon actions and processes - Creation of embodied carbon brief, setting out boundary,
Creation of embodied carbon brief, setting out boundary,
measurement points, information/data points, presentation
format etc. - 14 | 15
14 | 15 - Scale of opportunity
Scale of opportunity - to influence
to influence - embodied carbon
embodied carbon - Decide how to incorporate
Decide how to incorporate - embodied carbon through
embodied carbon through - existing in-house documents
existing in-house documents - Consider how embodied carbon
Consider how embodied carbon - objectives and requirements are to
objectives and requirements are to - be communicated to the design
be communicated to the design - and construction teams. The requirements can be
and construction teams. The requirements can be - embedded in a wide range of documents such as:
embedded in a wide range of documents such as:
This also needs to be included as part of the tender and
procurement process, which are essential parts in undertaking
and reducing embodied carbon. Some structural decisions are
made very early on in the process which can affect embodied
carbon. - scopes of service;
scopes of service; - At this point, the structural frame can be examined more
At this point, the structural frame can be examined more
easily, which is where a large proportion of embodied
carbon emissions are locked in, e.g. the amount of cement
replacement materials (CRMs) in the foundations. As the
design reaches final sign off, ability to influence decreases.
construction contracts. - Clients can influence a limited range of materials choices.
Clients can influence a limited range of materials choices.
Handover There are no further opportunities to influence the embodied
carbon of the build. However, clients will be able to influence,
guide and recommend for the fit-out. An embodied carbon
assessment at this stage can be valuable as a benchmark
against future projects, assuming there has been consideration
at earlier stages of how to gather the requisite data.
Operation It is not appropriate to do an embodied carbon assessment of
the original build at this stage as reductions cannot take place.
Significant future opportunities arise however when looking - at fit out, replacement cycles of plant and materials or when
at fit out, replacement cycles of plant and materials or when
a major renovation is due. However, at this stage a high level
assessment of the original build materials could be undertaken
which may help to understand the impacts of the assets.
Walsh | Bankside - HOW
HOW - Employers Requirements;
Employers Requirements; - specifications;
specifications; - requests for proposal; and
requests for proposal; and - The method used to communicate requirements may
The method used to communicate requirements may - also depend on when measurement processes start
also depend on when measurement processes start - and any iterations required.
and any iterations required. - Section 3.2 When?
Section 3.2 When? - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 3.5 Why?
3.5 Why? - Recognise the drivers for
Recognise the drivers for - the organisation to start to
the organisation to start to - measure embodied carbon
measure embodied carbon - and what the objectives of the
and what the objectives of the - assessment are
assessment are - Knowing how and what to ask for
Knowing how and what to ask for - WHY
WHY - Preparing a statement of relevant long term ambitions
Preparing a statement of relevant long term ambitions - and short term objectives will help make the supply
and short term objectives will help make the supply
chain aware of the environmental and carbon specific - aims of the client organisation. This can help to:
aims of the client organisation. This can help to:
align reporting needs; - aid with carbon transparency; and
aid with carbon transparency; and - Context and ambitions
Context and ambitions - improve data efficiencies further down the line.
improve data efficiencies further down the line. - Embodied carbon is just one aspect of the many
Embodied carbon is just one aspect of the many
sustainability concerns of a client. Explaining the full
context of the organisations approach to sustainability - allows the supply chain to respond to the embodied
allows the supply chain to respond to the embodied
carbon measurement request appropriately. - The statement could also be specific to property
The statement could also be specific to property - portfolio objectives such as developing a common
portfolio objectives such as developing a common - assessment framework in order to compare projects
assessment framework in order to compare projects - and demonstrate carbon performance over time.
and demonstrate carbon performance over time. - This context could include:
This context could include: - identifying any current company carbon or GHG
identifying any current company carbon or GHG - requirements
requirements - compulsory reporting standards e.g. mandatory
compulsory reporting standards e.g. mandatory - GHG reporting
GHG reporting - voluntary reporting standards e.g. CDP
voluntary reporting standards e.g. CDP - any environmental management system
any environmental management system - requirements that could be impacted by, or
requirements that could be impacted by, or - have an impact on, the embodied carbon data
have an impact on, the embodied carbon data
gathering process. - Matt Chisnall | Turnmill
Matt Chisnall | Turnmill - Section 4.1 Context, ambitions and aims for
Section 4.1 Context, ambitions and aims for - the example wording
the example wording - 3.6 What?
3.6 What? - Understand what the
Understand what the - embodied carbon brief
embodied carbon brief - should contain and what
should contain and what - decisions are needed for
decisions are needed for - each element.
each element. - 16 | 17
16 | 17 - WHAT
WHAT - Some reporting or assessment schemes determine
Some reporting or assessment schemes determine - what and how embodied carbon is assessed.
what and how embodied carbon is assessed. - Guidance: 5. Whole built
Guidance: 5. Whole built - 66 Supporting
66 Supporting - asset level assessment methodologies
asset level assessment methodologies - requirements for embodied carbon
requirements for embodied carbon - This section gives specific instructions on what is
This section gives specific instructions on what is - included in the embodied carbon calculation, which
included in the embodied carbon calculation, which - includes multiple variables. In order to fully understand
includes multiple variables. In order to fully understand
the embodied carbon figures, it is worth considering
how changing a variable of the calculation will impact
the final result. - 3.6.1 What are the objectives for an embodied
3.6.1 What are the objectives for an embodied
carbon assessment? - The calculation and the variables should not change,
The calculation and the variables should not change,
in order to ensure consistency of measurement within - a portfolio. This is preferable to enable meaningful
a portfolio. This is preferable to enable meaningful
comparisons. - I simply want an appreciation of embodied
I simply want an appreciation of embodied - carbon quantities in my asset.
carbon quantities in my asset. - Guidance: 6. Setting up
Guidance: 6. Setting up - 66 Supporting
66 Supporting - meaningful comparisons
meaningful comparisons - However, calculation variables may change, such as
However, calculation variables may change, such as
if a more sophisticated assessment is performed. - Consequently, it will not be possible to compare
Consequently, it will not be possible to compare
measurements with previous assessments. - It is useful to establish what is to be achieved from
It is useful to establish what is to be achieved from
knowing the embodied carbon impact of a built asset.
Consider the following: - I want to know the embodied carbon emissions
I want to know the embodied carbon emissions - of my asset at every stage of the design and
of my asset at every stage of the design and
delivery process. - I want to see reductions in the embodied carbon
I want to see reductions in the embodied carbon
footprint of my asset. - The objective will inform the choice of embodied
The objective will inform the choice of embodied - carbon assessment boundary.
carbon assessment boundary. - Clients are advised to use their first measurement as an
Clients are advised to use their first measurement as an
opportunity to drive down embodied carbon though - design and construction choices.
design and construction choices. - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Knowing how and what to ask for
Knowing how and what to ask for - 3.6.2 Boundaries
3.6.2 Boundaries - Consequently, the principal boundaries to consider are:
Consequently, the principal boundaries to consider are:
The boundary sets the scene for assessment and - further defines the emissions to be included or
further defines the emissions to be included or - excluded according to the life cycle of the built asset.
excluded according to the life cycle of the built asset.
Cradle-to-completed construction: - This will best reflect scenario 1 above (references
This will best reflect scenario 1 above (references
BS 15978 modules A1 to A5).*
The brief includes the most appropriate boundary for - an assessment. Put simply, understanding where to
an assessment. Put simply, understanding where to
draw the boundary is essentially deciding which of - these scenarios is a better fit:
these scenarios is a better fit: - Cradle-to-grave:
Cradle-to-grave: - This will best reflect scenario 2 above (references
This will best reflect scenario 2 above (references
BS 15978 modules A1-A5, B1-B5 and C1-C4 and,
optionally, D.) - Scenario 1:
Scenario 1: - I would like to know the carbon critical hotspots
I would like to know the carbon critical hotspots
and how much carbon has been generated in - delivering my asset, as it stands when I get the
delivering my asset, as it stands when I get the
keys - Scenario 2:
Scenario 2: - I would like to know how much carbon has been
I would like to know how much carbon has been
generated in delivering my asset, and I also want
to know how much will be generated when I
operate, maintain and dispose of my asset in the
future. - Guidance: 2. What is the technical
Guidance: 2. What is the technical - 66 Supporting
66 Supporting - basis for identifying life cycle stages?
basis for identifying life cycle stages? - There are other considerations that may be taken
There are other considerations that may be taken - when setting the boundary. Clients may opt to
when setting the boundary. Clients may opt to
look at issues relating to the boundary, such as
the procurement route, future ownership and - management as appropriate to the maturity of their
management as appropriate to the maturity of their - embodied carbon knowledge.
embodied carbon knowledge. - Clients may wish to use a boundary aligned with future
Clients may wish to use a boundary aligned with future
tenure arrangements. This boundary could be called - cradle-to-transfer of ownership and could be used in
cradle-to-transfer of ownership and could be used in - situations where clients wish to build, operate, maintain
situations where clients wish to build, operate, maintain
and then sell. It would cover BS 15978 modules A1-A5,
B1-B5. - *
* - BS EN 15978:2011 Sustainability of construction works. Assessment of environmental
BS EN 15978:2011 Sustainability of construction works. Assessment of environmental
performance of buildings. Calculation method. - Boundaries and Procurement,
Boundaries and Procurement, - Ownership and Management
Ownership and Management - When considering the boundary,
When considering the boundary, - it is also worthwhile to consider
it is also worthwhile to consider - how the asset is to be procured,
how the asset is to be procured, - constructed, and managed, along
constructed, and managed, along - with whether any ownership will
with whether any ownership will - be retained post-handover. This is
be retained post-handover. This is - useful because the perspectives
useful because the perspectives - of a developer-landlord differ
of a developer-landlord differ - from speculative developers or an
from speculative developers or an - owner-occupier. The assessment
owner-occupier. The assessment - results can help decision-making,
results can help decision-making, - especially for long-term issues, such
especially for long-term issues, such - as future climate change scenarios.
as future climate change scenarios. - Decisions on material choices will
Decisions on material choices will - differ based on the embodied
differ based on the embodied - carbon impact, which depends on
carbon impact, which depends on - the reference study period of the
the reference study period of the - assessment.
assessment. - The reference study period is
The reference study period is - the duration of time used in the
the duration of time used in the - assessment. For example, in a
assessment. For example, in a - cradle-to-grave assessment, the
cradle-to-grave assessment, the - reference study period(s) could be
reference study period(s) could be - 20 years, 60 years or 100 years i.e.
20 years, 60 years or 100 years i.e.
the period of time for which the - client wants information.
client wants information. - Consider the following examples
Consider the following examples - of how scenarios, boundaries and
of how scenarios, boundaries and - reference study periods interact:
reference study periods interact: - 18 | 19
18 | 19 - Example A: The company will be selling the asset on completion
Example A: The company will be selling the asset on completion
and therefore the company will not have information on the assets
use after the sale. An appropriate boundary for this situation could be
cradle-to-completed construction. - Example B: The company may sell the asset on completion but is still
Example B: The company may sell the asset on completion but is still
weighing up options to occupy or manage the asset for a minimum
term of 5-10 years. Selecting cradle-to-construction with an additional,
alternative calculation which includes the maintenance, repair and
replacement cycles for the period under consideration. - Example C: The company will retain the asset on completion and
Example C: The company will retain the asset on completion and
occupy and manage the asset for a minimum of 25 years. In this case
the company may wish to conduct a cradle-to-grave assessment as it
will include all the operational impacts they are likely to incur over the
operational period. - Example D: The company will occupy a tenanted area of a shell and
Example D: The company will occupy a tenanted area of a shell and
core developed asset and will be responsible for the fit-out, as well as
future management and maintenance, for the period of approximately
10 years. An appropriate boundary is cradle-to-grave for the fit-out
materials, which can be used to inform the embodied carbon impact of
the maintenance, repair and replacement cycles. - Example E: The company is planning to retain and operate the asset
Example E: The company is planning to retain and operate the asset
for 10 years at which point they are required to demolish the asset. In
this case, they may be interested in a cradle-to-grave assessment to
minimize future carbon liabilities and identify opportunities to recover
value from the materials/carbon already invested in the building.
Best practice for whole-life carbon assessment is to consider multiple
reference study periods and present results as a series of scenarios.
A practical starting point is a commitment to a cradle-to-completed
construction boundary. This provides a well-balanced picture of the
embodied carbon footprint of the asset in question as it stands in reality,
regardless of the ownership structure and future tenure.
Over time, it would be advisable for clients, particularly those involved in
ongoing operation and maintenance, to be more involved in cradle-to-grave
issues. Using a wider boundary offers the opportunity for a more in-depth
understanding of: - the impact of decisions at the capital expenditure stage which affect
the impact of decisions at the capital expenditure stage which affect
embodied carbon on the operational carbon in the use stage; and
the embodied carbon impact of maintenance and replacement cycles.
Understanding both of these issues can help clients with design decisions
and materials choices. - Section 4.2 Assessment boundary and reference study period
Section 4.2 Assessment boundary and reference study period - for the example wording
for the example wording - Carillion | Manchester Metropolitan Hospital
Carillion | Manchester Metropolitan Hospital - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Assumptions and Certainty
Assumptions and Certainty - Two issues to be aware of when undertaking an
Two issues to be aware of when undertaking an
embodied carbon calculation are: - the level of certainty of the data available at the
the level of certainty of the data available at the
time of assessment; and - the standardised assumptions that are made
the standardised assumptions that are made - about the life cycle of assets e.g. maintenance
about the life cycle of assets e.g. maintenance
regimes. - Embodied carbon assessments are estimates unless
Embodied carbon assessments are estimates unless - the calculation is performed on an as-built asset
the calculation is performed on an as-built asset - with a complete embodied carbon data set and only
with a complete embodied carbon data set and only
measuring up to the point of handover. Consequently,
the level of uncertainty in an assessment depends on
where the project is in the life cycle and how far into
the future the calculation is taken. - If the starting point is at the conceptual design
If the starting point is at the conceptual design
stage of a project, the assessment will be based on
assumptions and best guesses as to what materials - the final asset may contain. As the design progresses,
the final asset may contain. As the design progresses,
certainty around the materials in the asset increases - and therefore, the embodied carbon assessment
and therefore, the embodied carbon assessment - becomes more certain. It is recommended that
becomes more certain. It is recommended that - provision is made in the brief to repeat the assessment
provision is made in the brief to repeat the assessment
Knowing how and what to ask for - throughout the design stages to make the final
throughout the design stages to make the final - assessment as accurate as possible.
assessment as accurate as possible. - Certainty also decreases the further into the future
Certainty also decreases the further into the future - life cycle of the asset that the assessment covers.
life cycle of the asset that the assessment covers.
When looking over the whole asset life, the less
certain the data becomes given that the future - management and operational regime are unknown
management and operational regime are unknown - and cannot always be predicted accurately. In
and cannot always be predicted accurately. In - scenarios where the maintenance regime and
scenarios where the maintenance regime and - replacement cycle is not known, assumptions
replacement cycle is not known, assumptions - have to be made in order to give a reasonable
have to be made in order to give a reasonable
embodied carbon estimate. An awareness that - these assumptions have been used is valuable
these assumptions have been used is valuable - in understanding the final result of an embodied
in understanding the final result of an embodied - carbon assessment.
carbon assessment. - Where possible, stating the known, or assumed,
Where possible, stating the known, or assumed,
operational regimes and end of life scenarios of the
asset is recommended. Where there are unknowns,
clients can engage with the assessors in order to
determine the most appropriate assumptions. This - will prevent assessors having to make arbitrary
will prevent assessors having to make arbitrary - assumptions. Transparency of the assumptions will
assumptions. Transparency of the assumptions will - assist with future comparability across a clients
assist with future comparability across a clients - portfolio.
portfolio. - 3.6.3 Assessment scope
3.6.3 Assessment scope - The assessment scope sets out what is included and
The assessment scope sets out what is included and
excluded from the embodied carbon measurement. - The assessment scope may be defined as:
The assessment scope may be defined as: - a project level, e.g. new construction or fit-out;
a project level, e.g. new construction or fit-out;
an asset level; - an activity level, e.g. solely the structure of a single
an activity level, e.g. solely the structure of a single
asset or across a portfolio. - The scope will also include a description of the physical
The scope will also include a description of the physical
parameters of an asset e.g. gross floor area (GFA).
This is necessary to enable the results to be suitably
presented. It is good practice to include a description
of the use of an asset. - Section 4.7 Presenting the results
Section 4.7 Presenting the results - It should be noted that the scope is distinct from the
It should be noted that the scope is distinct from the
boundary of the assessment. The boundary defines the
life cycle stages to be included. The scope defines the
particular emissions that are included or excluded in - every life cycle stage of the boundary.
every life cycle stage of the boundary. - Scope considerations might include:
Scope considerations might include: - Is there a physical or geographical boundary?
Is there a physical or geographical boundary? - e.g. is the curtilage of the assessment site clearly
e.g. is the curtilage of the assessment site clearly
defined? - Is there a project boundary with an associated
Is there a project boundary with an associated - cost plan?
cost plan? - What level of detail is needed? e.g. Can the
What level of detail is needed? e.g. Can the
80:20 rule be applied in order to identify the high
intensity/high volume embodied carbon areas? - What activities are included? e.g. Will the
What activities are included? e.g. Will the
embodied emissions of the materials and the - construction site emissions of every single activity
construction site emissions of every single activity - on the project be included?
on the project be included? - Define any exclusions from the assessment. e.g.
Define any exclusions from the assessment. e.g.
demolition emissions. - Section 4.3 Assessment scope for the example
Section 4.3 Assessment scope for the example - scope wording
scope wording - Figure 4 Conceptual diagram showing ability to influence carbon reduction across the different work stages
Figure 4 Conceptual diagram showing ability to influence carbon reduction across the different work stages
of infrastructure delivery[22] - 20 | 21
20 | 21 - 3.6.4 Assessment standards and calculation
3.6.4 Assessment standards and calculation - methodology
methodology - For embodied carbon assessments of built assets, the
For embodied carbon assessments of built assets, the
use of the standard BS 15978 is becoming an industry
norm.[23] This standard sets out a basic methodology
for life cycle assessment (LCA) in buildings by splitting
the life cycle into modules. These modules are used to
structure the embodied carbon calculation. - Guidance: 2. What is the technical
Guidance: 2. What is the technical - 66 Supporting
66 Supporting - basis for identifying life cycle stages?
basis for identifying life cycle stages? - For civil engineering works there is a pending standard,
For civil engineering works there is a pending standard,
prEN 15643-5:2016 Sustainability of Construction - Works Sustainability Assessment of Buildings and
Works Sustainability Assessment of Buildings and - Civil Engineering Works Part 5: Framework for the
Civil Engineering Works Part 5: Framework for the
Assessment of Sustainability Performance of Civil - Engineering Works.[24]
Engineering Works.[24] - For the infrastructure sector, there is also PAS 2080
For the infrastructure sector, there is also PAS 2080
which is a carbon management framework. - Finally, RICS has produced a detailed embodied
Finally, RICS has produced a detailed embodied - carbon calculation methodology which builds on the
carbon calculation methodology which builds on the - BS 15978 assessment standard.[25] Currently, assessors
BS 15978 assessment standard.[25] Currently, assessors
will typically choose either to use this methodology - or develop their own approach. Conforming to one
or develop their own approach. Conforming to one
or more of the above standards and methodologies - can provide a more robust process for, and a greater
can provide a more robust process for, and a greater
degree of confidence in, any calculations of embodied
carbon figures. - Guidance: 3.1 Presenting LCA
Guidance: 3.1 Presenting LCA - 66 Supporting
66 Supporting - results in a structured format
results in a structured format - Section 4.4 Assessment standards and
Section 4.4 Assessment standards and - calculation methodology for the example
calculation methodology for the example - scope wording
scope wording - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Knowing how and what to ask for
Knowing how and what to ask for - 3.6.5 Data and tools
3.6.5 Data and tools - 3.6.6 Presenting the figures
3.6.6 Presenting the figures - Embodied carbon calculations need conversion factors
Embodied carbon calculations need conversion factors - to convert quantities of materials into embodied
to convert quantities of materials into embodied - carbon figures. For this, there are a number of data
carbon figures. For this, there are a number of data
sources available. The assessment standards or - calculation methodologies do not endorse particular
calculation methodologies do not endorse particular - embodied carbon data sources (with the exception of
embodied carbon data sources (with the exception of
environmental product declarations (EPDs)). - The final part of the brief specifies how the embodied
The final part of the brief specifies how the embodied
carbon assessment should be presented. It is useful
to have the information broken down in a variety of
ways in order to make easier comparisons between - assets. Comparisons between assets which have used
assets. Comparisons between assets which have used - exactly the same boundary and the same calculation
exactly the same boundary and the same calculation - methodology are possible.
methodology are possible. - If multiple assessments are being conducted, defining
If multiple assessments are being conducted, defining - which dataset and tool are used in the embodied
which dataset and tool are used in the embodied
carbon calculations will improve the consistency of the - results.
results. - 66 Supporting Guidance: 4.1 Data and 4.3 Tools
66 Supporting Guidance: 4.1 Data and 4.3 Tools
Data Quality - The quality of data in embodied carbon assessments
The quality of data in embodied carbon assessments - varies according to its source. There are data quality
varies according to its source. There are data quality
standards, which clients can specify to ensure a robust
approach to embodied carbon calculations is adopted. - 66 Supporting Guidance: 4.1 Data
66 Supporting Guidance: 4.1 Data - Clients can also specify if the assessment should use
Clients can also specify if the assessment should use
verifiable data (and can request proof for audit, if
required). It is recommended to ask an assessor to
outline which standards can be complied with and to
verify all data sources used in the calculations.
Section 4.5 Data and tools for the example - wording
wording - Guidance: 6. Setting up
Guidance: 6. Setting up - 66 Supporting
66 Supporting - meaningful comparisons
meaningful comparisons - The results of an assessment might be broken down
The results of an assessment might be broken down
by: - Structural building elements, e.g. substructure,
Structural building elements, e.g. substructure,
superstructure etc.; - Components, e.g. walls, floors, cladding etc.;
Components, e.g. walls, floors, cladding etc.;
Carbon sources, e.g. transport, materials, site
activities etc.; - Work package; and
Work package; and - 22 | 23
22 | 23 - The data should be presented in line with the
The data should be presented in line with the
requirements set out in the scope which should include
physical parameters of an asset e.g. tCO2e/m2 GFA. The
results of the assessment can also be normalised in
terms of the functionality of an asset e.g. kgCO2e/FTE.
These intensity metrics should be in line with a clients
normal practice. - 66 Supporting Guidance: 8. Targets
66 Supporting Guidance: 8. Targets - Best practice is also to request that the timing of
Best practice is also to request that the timing of
emissions is clearly stated e.g. where maintenance and
repair cycles are considered. - As well as presenting the figures, the assessment
As well as presenting the figures, the assessment
should detail all assumptions that have been made,
e.g. maintenance regimes, and be reported within
the relevant section of the output, e.g. the assumed
maintenance regime is reported within the boundary - section.
section. - Section 4.7 Presenting the results for the
Section 4.7 Presenting the results for the - example wording
example wording - Location.
Location. - Presenting the data in a variety of ways highlights
Presenting the data in a variety of ways highlights
issues such as: - Section 6. What to do with the outputs?
Section 6. What to do with the outputs?
where the carbon hotspots are; - what kind of control the client has over them;
what kind of control the client has over them;
how the asset will be affected by proposed - mitigation measures; and
mitigation measures; and - who should be involved in the mitigation
who should be involved in the mitigation - measures decisions.
measures decisions. - Derwent London | Turnmill
Derwent London | Turnmill - Derwent London | Turnmill
Derwent London | Turnmill - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 4. Creating the brief
4. Creating the brief - Putting pen to paper
Putting pen to paper - This section is designed to help with writing the embodied carbon brief
This section is designed to help with writing the embodied carbon brief
and provides example wording. Below are suggested sections to include
which cover the major elements of an embodied carbon commissioning
document. - Each section includes:
Each section includes: - An explanation as to why the section should be included;
An explanation as to why the section should be included;
Example wording. - In the example wording, where content is highlighted in < > brackets,
In the example wording, where content is highlighted in < > brackets,
individual company information should be inserted. - 4.1 Context, ambitions and aims
4.1 Context, ambitions and aims - The brief starts by informing the assessor of the need for the embodied
The brief starts by informing the assessor of the need for the embodied
carbon assessment. This could include: - Creating the brief Putting pen to paper
Creating the brief Putting pen to paper - 24 | 25
24 | 25 - Example wording:
Example wording: - Example 1:
Example 1: - has committed to achieving lower embodied
has committed to achieving lower embodied - carbon emissions in line with 2050 targets and it is aiming to achieve
carbon emissions in line with 2050 targets and it is aiming to achieve
a carbon neutral status by 2030. - Example 2:
Example 2: - is undergoing its first steps into embodied
is undergoing its first steps into embodied - carbon assessment and would like to understand the embodied
carbon assessment and would like to understand the embodied
carbon impact of its assets. There is also an overarching company
objective to explore our Scope 3 emissions as part of our CDP
reporting process. Ongoing embodied carbon assessment forms part
of our ISO 14001 certification. - Example 3:
Example 3: - has an interest in delivering low impact assets
has an interest in delivering low impact assets - and is therefore interested in measuring the embodied carbon
and is therefore interested in measuring the embodied carbon
impact. Sustainability is a core value of our business and we seek to
make all of our new assets carbon neutral by 2025. We will achieve
this through operational efficiency and through reducing embodied - impacts.
impacts. - Example 4:
Example 4: - would like to understand the relationship
would like to understand the relationship - between cost, efficiency and low embodied carbon buildings.
between cost, efficiency and low embodied carbon buildings.
the company specific context; - relevant sustainability objectives;
relevant sustainability objectives; - Optional wording 1:
Optional wording 1: - relevant overall carbon aims;
relevant overall carbon aims; - The embodied carbon assessment must also be aligned with, and
The embodied carbon assessment must also be aligned with, and
deliver compatible data for, our existing carbon processes including:
previous experience and/or studies in embodied carbon
measurement and reduction; and - identifying any drivers and objectives as to why this data is required.
identifying any drivers and objectives as to why this data is required.
ISO 14064-1 Greenhouse gases Part 1: Specification with
guidance at the organization level for quantification and - reporting of greenhouse gas emissions and removals.
reporting of greenhouse gas emissions and removals. - ISO 14064-2 Greenhouse gases Part 2: Specification with
ISO 14064-2 Greenhouse gases Part 2: Specification with
guidance at the project level for quantification, monitoring and
reporting of greenhouse gas emission reductions or removal - enhancements.
enhancements. - The Greenhouse Gas (GHG) Protocol Scope 3 Standard;
The Greenhouse Gas (GHG) Protocol Scope 3 Standard;
Matt Chisnall | Turnmill - PAS 2080:2016 Carbon management in infrastructure.
PAS 2080:2016 Carbon management in infrastructure. - Additional wording:
Additional wording: - Regular embodied carbon reporting of our assets which
Regular embodied carbon reporting of our assets which - informs our selection of materials, products and suppliers
informs our selection of materials, products and suppliers
throughout the project and on future projects.*
* This wording can be used independently or in addition to the preceding points.
Matt Chisnall - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - 4.2 Assessment boundary and reference
4.2 Assessment boundary and reference - study period
study period - The brief sets the most relevant boundary for an
The brief sets the most relevant boundary for an
organisations interests and future planning. The - example wording refers to the two most often used
example wording refers to the two most often used
boundary conditions for clients as well as using the
potential cradle-to-transfer of ownership boundary. - Creating the brief Putting pen to paper
Creating the brief Putting pen to paper - 4.3 Assessment scope
4.3 Assessment scope - This section defines the scope of the assessment,
This section defines the scope of the assessment,
which may be at a project, asset or activity level, e.g.
new construction, a refurbishment or strip out/fit out.
If helpful, further detail can be given around which
project activities are included and excluded from the - calculation.
calculation. - 4.4 Assessment standards and calculation
4.4 Assessment standards and calculation - methodology
methodology - The brief then sets out any standards or calculation
The brief then sets out any standards or calculation
methodologies to which the assessment should - conform. The calculation methodology is a choice
conform. The calculation methodology is a choice - between the RICS Methodology or the assessors
between the RICS Methodology or the assessors - own approach. Calculations which do not use these
own approach. Calculations which do not use these
standards or methodologies should request the - assessor to justify this choice and explain the approach
assessor to justify this choice and explain the approach
used. - 26 | 27
26 | 27 - 4.5 Data and tools
4.5 Data and tools - The next step is to request that the data sources are
The next step is to request that the data sources are
disclosed in the report. Clients may outline which
embodied carbon data, databases and calculation tools - are preferred. This section could also stipulate the data
are preferred. This section could also stipulate the data
quality control rules. - Example wording:
Example wording: - Example wording:
Example wording: - Example wording:
Example wording: - Example wording:
Example wording: - Example 1:
Example 1: - The boundary to be used is cradle-to-completed
The boundary to be used is cradle-to-completed - construction, comprising BS 15978 modules
construction, comprising BS 15978 modules - A1-A5.
A1-A5. - Asset Function:
Asset Function: - The asset being assessed will be an .
The asset being assessed will be an . - Example 1:
Example 1: - All assessments undertaken must have
All assessments undertaken must have - their methods conform with BS 15978:2011
their methods conform with BS 15978:2011 - Sustainability of construction works
Sustainability of construction works - Assessment of environmental performance of
Assessment of environmental performance of - buildings
buildings - The following industry data and/or databases are
The following industry data and/or databases are
preferred for embodied carbon calculations: - Example 2:
Example 2: - The boundary to be used is cradle-to-grave,
The boundary to be used is cradle-to-grave, - comprising BS 15978 modules A1-A5 and B1
comprising BS 15978 modules A1-A5 and B1
to B5 over a 30-year reference study period.
Module D benefits are to be excluded. - Example 3:
Example 3: - The boundary to be used is cradle-to-grave,
The boundary to be used is cradle-to-grave, - comprising BS 15978 modules A1 to C4
comprising BS 15978 modules A1 to C4 - (excluding B6 and B7) i.e. including demolition,
(excluding B6 and B7) i.e. including demolition,
transport, waste processing and disposal, over - a 60-year reference study period. Module D
a 60-year reference study period. Module D
benefits are to be included. - Example 4:
Example 4: - The boundary to be used is cradle-to-transfer
The boundary to be used is cradle-to-transfer - of ownership, comprising BS 15978 modules
of ownership, comprising BS 15978 modules - A1 to C4 (excluding B6 and B7) over a 20-year
A1 to C4 (excluding B6 and B7) over a 20-year
reference study period. - Example 5:
Example 5: - The boundary to be used is cradle-to-transfer of
The boundary to be used is cradle-to-transfer of - ownership, comprising BS 15978 modules A1 to
ownership, comprising BS 15978 modules A1 to - C4 (excluding B6 and B7) over 10-year, 20-year
C4 (excluding B6 and B7) over 10-year, 20-year
and 60-year reference study periods. - Derwent London
Derwent London - Example 1:
Example 1: - The scope is limited to an assessment of
The scope is limited to an assessment of - the structural components (sub-structure,
the structural components (sub-structure, - superstructure and faade) of .
superstructure and faade) of . - Example 2:
Example 2: - The scope is limited to the fit-out of including floor and wall finishes as well
The scope is limited to the fit-out of including floor and wall finishes as well
as major interior items. - Example 3:
Example 3: - The scope is limited to an assessment of
The scope is limited to an assessment of - including earthworks,
including earthworks, - demolition, all construction materials, construction
demolition, all construction materials, construction - operations and maintenance.
operations and maintenance. - Example 4:
Example 4: - The scope of the assessment will include direct
The scope of the assessment will include direct - and indirect GHG emissions associated with
and indirect GHG emissions associated with - .
. - Example 5:
Example 5: - The scope of the assessment will exclude
The scope of the assessment will exclude - emissions from design stage (paper and office
emissions from design stage (paper and office - consumption) and worker commuting activities.
consumption) and worker commuting activities. - Example 2:
Example 2: - The methodology for calculation will be based
The methodology for calculation will be based - on the RICS 2014 Methodology to Calculate
on the RICS 2014 Methodology to Calculate - Embodied Carbon. Any deviations from this must
Embodied Carbon. Any deviations from this must - be justified and agreed.
be justified and agreed. - Example 3:
Example 3: - The methodology for calculation will conform
The methodology for calculation will conform - to BS 15978:2011 and will also use the RICS
to BS 15978:2011 and will also use the RICS
Methodology to calculate embodied carbon. - Data gathering shall conform to ISO 14025:2010
Data gathering shall conform to ISO 14025:2010 - Environmental labels and declarations. Type
Environmental labels and declarations. Type - III environmental declarations. Principles and
III environmental declarations. Principles and - procedures. An audit trail shall be presented.
procedures. An audit trail shall be presented.
Environmental Product Declarations (EPDs) - Proprietary data and databases
Proprietary data and databases - The University of Bath ICE database
The University of Bath ICE database - The following calculation tools are preferred:
The following calculation tools are preferred: - Any proprietary tools may also be considered
Any proprietary tools may also be considered - if they are demonstrated to create materially
if they are demonstrated to create materially - similar outputs as the other accepted tools.
similar outputs as the other accepted tools. - Differences in calculations should be justified.
Differences in calculations should be justified. - Data quality:
Data quality: - The assessment shall include a general
The assessment shall include a general - commentary on data quality for the project.
commentary on data quality for the project. - Scoring of data quality for each data source is
Scoring of data quality for each data source is
also recommended.* - * This wording can be used independently or in addition to the preceding points.
* This wording can be used independently or in addition to the preceding points.
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Creating the brief Putting pen to paper
Creating the brief Putting pen to paper - 4.6 Starting point, iterations and frequency
4.6 Starting point, iterations and frequency - 4.7 Presenting the results
4.7 Presenting the results - The brief states the stages at which the assessment
The brief states the stages at which the assessment
will take place i.e. the starting point and details any
further iterations. If this embodied carbon assessment - is the first, it can be used as a baseline for future
is the first, it can be used as a baseline for future
comparisons. It should be noted that the starting point
has an impact on the opportunities for embodied - carbon reductions.
carbon reductions. - The brief states the way in which the final assessment
The brief states the way in which the final assessment
is presented. This will include all assumptions that have
been made. - A comprehensive breakdown of the results will enable
A comprehensive breakdown of the results will enable - the client to better understand where the embodied
the client to better understand where the embodied - carbon impact lies. This depth of understanding can be
carbon impact lies. This depth of understanding can be
used to inform decisions made at later stages in the
project and on future projects. - Clients can request a list of reduction strategy
Clients can request a list of reduction strategy - suggestions e.g. the top five which would have the
suggestions e.g. the top five which would have the
Example wording: - Example 1:
Example 1: - Three iterations of the assessment are required.
Three iterations of the assessment are required. - 1.
1. - Concept design stage.
Concept design stage. - 2.
2. - Detailed design stage.
Detailed design stage. - 3.
3. - Handover stage.
Handover stage. - For the second and third assessments, differences
For the second and third assessments, differences - to the initial assessment shall be provided and
to the initial assessment shall be provided and - explained.
explained. - Example 2:
Example 2: - The initial assessment will be at the detailed design
The initial assessment will be at the detailed design
stage. Two further iterations are required prior to the
construction phase and a final as-built assessment. - These iterations align to our standard gate process
These iterations align to our standard gate process - stages .
stages . - Derwent London
Derwent London - 28 | 29
28 | 29 - most impact. Alternatively, the list of suggestions
most impact. Alternatively, the list of suggestions
could be based on parameters such as the materials
used in the elements and components, or reductions
achievable in each project stage after the assessment.
The example wording uses generic terminology for - breakdowns of building elements and components.
breakdowns of building elements and components. - Official RICS terminology can be used to avoid
Official RICS terminology can be used to avoid - confusion and different interpretations. Alternatively,
confusion and different interpretations. Alternatively, - in-house terminology can be used for the breakdown
in-house terminology can be used for the breakdown - detail.
detail. - Example wording:
Example wording: - Example 3:
Example 3: - The starting point will be at briefing stage and
The starting point will be at briefing stage and
there will be periodic iterations of the assessment.
wishes to frequently monitor - the embodied carbon and understand how material
the embodied carbon and understand how material - selection may affect the final outcome. Number and
selection may affect the final outcome. Number and
timing of iterations are to be agreed in conjunction
with the embodied carbon assessor. - Example 4:
Example 4: - The results of the assessment are required at
The results of the assessment are required at - handover stage. It is the assessors responsibility to
handover stage. It is the assessors responsibility to
advise as to the most appropriate stages to engage
in order to deliver a robust assessment. - Optional wording (as required):
Optional wording (as required): - Where the first assessment is to be before product
Where the first assessment is to be before product
selection, initial calculations should be based on - or use estimated
or use estimated - quantities and . This generic
quantities and . This generic - data should be substituted for detailed product data
data should be substituted for detailed product data - as the design progresses and subsequent iterations
as the design progresses and subsequent iterations - of the assessment are prepared.
of the assessment are prepared. - Assumptions:
Assumptions: - Additionally, the breakdown shall include:
Additionally, the breakdown shall include: - All assumptions must be clearly stated.
All assumptions must be clearly stated. - .
. - Clients can choose any of the following
Clients can choose any of the following - potential breakdown examples that are
potential breakdown examples that are - appropriate.
appropriate. - The results of the assessment shall be presented in
The results of the assessment shall be presented in
the following way: - Total kgCO2e per building element as defined
Total kgCO2e per building element as defined - as: .
as: . - Total kgCO2e per material as defined as:
Total kgCO2e per material as defined as:
. - Total kgCO2e per major building component as
Total kgCO2e per major building component as - defined as .
defined as . - Total kgCO2e per work package.
Total kgCO2e per work package. - Total kgCO2e by location.
Total kgCO2e by location. - and .
and . - .
. - The assessment shall provide the top
The assessment shall provide the top - suggestions for reducing embodied carbon impact
suggestions for reducing embodied carbon impact - (including the reasoning) to inform the next stage of
(including the reasoning) to inform the next stage of
the project. - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Example Brief
Example Brief - 30 | 31
30 | 31 - 5. Example Brief
5. Example Brief - The example brief below assembles a selection of
The example brief below assembles a selection of - the example wording from Section 4 into a single
the example wording from Section 4 into a single
document. - EMBODIED CARBON BRIEF 2
EMBODIED CARBON BRIEF 2 - EMBODIED CARBON BRIEF
EMBODIED CARBON BRIEF - The brief starts by informing
The brief starts by informing - the assessor of the need for the
the assessor of the need for the - embodied carbon assessment. This
embodied carbon assessment. This - could include:
could include: - the company specific context;
the company specific context; - relevant sustainability
relevant sustainability - objectives;
objectives; - relevant overall carbon aims;
relevant overall carbon aims; - previous experience and/or
previous experience and/or - studies in embodied carbon
studies in embodied carbon - measurement and reduction;
measurement and reduction; - and
and - identifying drivers and
identifying drivers and - objectives for the data.
objectives for the data. - Data and tools
Data and tools - The following industry data and/or databases are preferred for embodied carbon calculations:
The following industry data and/or databases are preferred for embodied carbon calculations:
Context and company objectives - Environmental Product Declarations (EPDs)
Environmental Product Declarations (EPDs) - has an interest in delivering low impact assets and is therefore interested in
has an interest in delivering low impact assets and is therefore interested in
measuring the embodied carbon impact. Sustainability is a core value of our business and we seek to
make all of our new assets carbon neutral by 2025. We will achieve this through operational efficiency
and through reducing embodied impacts. - Proprietary data and database
Proprietary data and database - The embodied carbon assessment must also be aligned with, and deliver compatible data for, our
The embodied carbon assessment must also be aligned with, and deliver compatible data for, our
existing carbon processes including: - Impact-compliant tools
Impact-compliant tools - ISO 14064-2 Greenhouse gases Part 2: Specification with guidance at the project level for
ISO 14064-2 Greenhouse gases Part 2: Specification with guidance at the project level for
quantification, monitoring and reporting of greenhouse gas emission reductions or removal
enhancements. - The assessment shall include a general commentary on data quality for the project. Scoring of data
The assessment shall include a general commentary on data quality for the project. Scoring of data
quality for each data source is recommended. - Regular embodied carbon reporting of our assets which informs our selection of materials,
Regular embodied carbon reporting of our assets which informs our selection of materials,
products and suppliers throughout the project and on future projects.
Boundary - The assessment will report on three boundaries, as defined using BS 15978:2011 Sustainability of
The assessment will report on three boundaries, as defined using BS 15978:2011 Sustainability of
construction works. Assessment of environmental performance of buildings. Calculation method.
1. - Cradle-to-completed construction, comprising BS 15978 modules A1-A5.
Cradle-to-completed construction, comprising BS 15978 modules A1-A5.
2. Cradle-to-transfer of ownership, comprising BS 15978 modules A1 to C4 (excluding B6 and B7)
over 10-year, 20-year and 60-year reference study periods.
3. Cradle-to-grave, comprising BS 15978 modules A1 to C4 (i.e. including demolition, transport, waste
processing and disposal) over a 60-year reference study period.
The brief sets the most relevant - boundary for the organisations
boundary for the organisations - interests and future planning.
interests and future planning. - Scope of the embodied carbon assessment
Scope of the embodied carbon assessment - Any proprietary tools may also be considered if they are demonstrated to create the same outputs
Any proprietary tools may also be considered if they are demonstrated to create the same outputs
Starting point, iterations and frequency - The starting point will be at briefing stage and there will be periodic iterations of the assessment.
The starting point will be at briefing stage and there will be periodic iterations of the assessment.
wishes to frequently monitor the embodied carbon and understand how
material selection may affect the final outcome. Number and timing of iterations are to be agreed in
conjunction with the embodied carbon assessor. - Where the first assessment is to be before product selection, initial calculations should be based on
Where the first assessment is to be before product selection, initial calculations should be based on
RICS component benchmarks or use estimated quantities and the GaBi database. This generic data
should be substituted for detailed product data as the design progresses and subsequent iterations of
the assessment are prepared. - Presenting the results
Presenting the results - All assumptions must be clearly stated.
All assumptions must be clearly stated. - The assessment shall include the structural components (sub-structure, superstructure and faade). The
The assessment shall include the structural components (sub-structure, superstructure and faade). The
fit-out, floor and wall finishes, as well as major interior items, are included.
Total kgCO2e per material as defined as: foundation concrete, structural steel, etc.
Assessment standards and calculation methodology - The methodology for calculation will conform to BS 15978:2011 and will also use the RICS
The methodology for calculation will conform to BS 15978:2011 and will also use the RICS
Methodology to calculate embodied carbon. Data gathering shall conform to ISO 14025:2010
Environmental labels and declarations. Type III environmental declarations. Principles and procedures.
An audit trail shall be presented. - This section states the stage at
This section states the stage at - which the assessment will take
which the assessment will take - place i.e. the starting point, and
place i.e. the starting point, and
details any further iterations. If this - embodied carbon assessment is the
embodied carbon assessment is the - first, it can be used as a baseline
first, it can be used as a baseline
for future comparisons. It should be - noted that the starting point has
noted that the starting point has - an impact on the opportunities for
an impact on the opportunities for - embodied carbon reductions.
embodied carbon reductions. - The results of the assessment shall be presented in the following way:
The results of the assessment shall be presented in the following way:
Total kgCO2e per building element as defined as: substructure, superstructure, cladding, exterior
works, services, and any other major element.
This section sets out any standards or calculation methodologies
to which the assessment should conform. The calculation
methodology is a choice between the RICS Methodology or the
assessors own approach. Calculations which do not use these
standards or methodologies should request the assessor to - justify this choice and explain the approach used.
justify this choice and explain the approach used.
Matt Chisnall - The following calculation tools are acceptable:
The following calculation tools are acceptable: - Asset function: The asset being assessed will be a mixed use development incorporating residential and
Asset function: The asset being assessed will be a mixed use development incorporating residential and
retail tenants. - The assessment will exclude emissions from design stage (paper and office consumption) and worker
The assessment will exclude emissions from design stage (paper and office consumption) and worker
commuting activities. - This section defines the scope of
This section defines the scope of - the assessment, which may be at
the assessment, which may be at - a project, asset or activity level e.g.
a project, asset or activity level e.g.
new construction, refurbishment or - strip out/fit out. If helpful, further
strip out/fit out. If helpful, further
detail can be given around which - project activities are included and
project activities are included and - excluded from the calculation.
excluded from the calculation. - GaBi database
GaBi database - Clients may outline which
Clients may outline which - embodied carbon data, databases
embodied carbon data, databases - and calculation tools are preferred
and calculation tools are preferred - and request that the data sources
and request that the data sources - are disclosed. This section could
are disclosed. This section could - also stipulate the data quality
also stipulate the data quality - control rules.
control rules. - Total kgCO2e per major building component as defined as: frame, internal and external walls, floors,
Total kgCO2e per major building component as defined as: frame, internal and external walls, floors,
roof, windows and doors, etc. - Total kgCO2e per work package.
Total kgCO2e per work package. - The results shall include intensity metrics, as defined by: kgCO2e per m2 and tCO2e per 100k cost,
The results shall include intensity metrics, as defined by: kgCO2e per m2 and tCO2e per 100k cost,
kgCO2e per residential occupant. - Each breakdown should be expressed as a proportion (%) of the total embodied carbon footprint.
Each breakdown should be expressed as a proportion (%) of the total embodied carbon footprint.
The assessment shall provide the top five suggestions for reducing embodied carbon impact (including
the reasoning) to inform the next stage of the project.
This section states the way in which the final
assessment is presented. This will include - all assumptions that have been made. A
all assumptions that have been made. A - comprehensive breakdown of the results will
comprehensive breakdown of the results will - enable the client to better understand where
enable the client to better understand where - the embodied carbon impact lies. This depth
the embodied carbon impact lies. This depth - of understanding can be used to inform
of understanding can be used to inform - decisions made at later stages in the project
decisions made at later stages in the project - and on future projects.
and on future projects. - Clients can request a list of reduction strategy
Clients can request a list of reduction strategy - suggestions, e.g. the top five which would
suggestions, e.g. the top five which would
have the most impact. Alternatively, the list of
suggestions could be based on parameters - such as the materials used in the elements
such as the materials used in the elements - and components, or reductions achievable in
and components, or reductions achievable in - each project stage after the assessment.
each project stage after the assessment. - 6. What to do with the
6. What to do with the - outputs?
outputs? - Use of the embodied carbon assessment depends on when the
Use of the embodied carbon assessment depends on when the
assessment was carried out. If the assessment was undertaken at
conceptual design stage, the embodied carbon report can give clients
an opportunity to make decisions at subsequent stages in the project to
reduce the predicted embodied carbon outcome. - If the assessment was undertaken to understand the as-built embodied
If the assessment was undertaken to understand the as-built embodied
carbon, this could be used as a benchmark for future projects. Earlier initial
assessments and frequent iterations throughout the construction process - will reveal more opportunities for embodied carbon reduction.
will reveal more opportunities for embodied carbon reduction.
6.1 Benchmarking - Once the first assessment is completed, a benchmark exists with which to
Once the first assessment is completed, a benchmark exists with which to
compare future projects. Direct comparisons can be made between assets
which have had the same boundaries, scope, assessment methodology
etc. applied. Comparisons of the embodied carbon between different
typologies may be useful, however, the degree of fit-out will vary
considerably e.g. embodied carbon of warehouses as compared to a retail
building. - If built assets are not part of the core business, or the client is a pop-up
If built assets are not part of the core business, or the client is a pop-up
client created to deliver a one-off asset, the embodied carbon data is
useful to publicly publish the embodied carbon data or feed into an
industry collective benchmark project, e.g. Embodied Carbon Database.[26]
32 | 33 - 6.2 Target setting
6.2 Target setting - 6.3 Reducing embodied carbon
6.3 Reducing embodied carbon - A target is not necessary for a client to commission
A target is not necessary for a client to commission
an initial embodied carbon assessment. It is more
important to ensure clarity of the objectives of the
exercise and how the outputs will be used. As more
assessments are completed, it will become easier to
set a target. Embodied carbon targets can be as simple
as a reduction against an initial calculation or can be an
absolute figure for the defined scope. Clients should be
mindful of using accurate like-for-like comparisons. - It is recommended that in order to maximise
It is recommended that in order to maximise - the opportunity for embodied carbon reduction,
the opportunity for embodied carbon reduction, - assessments are undertaken as early on in the design
assessments are undertaken as early on in the design
process as possible. - The same caveats of similar boundaries, scope,
The same caveats of similar boundaries, scope,
methodologies etc. that exist for benchmarking, apply
for target setting. - 66 Supporting Guidance: 8. Targets
66 Supporting Guidance: 8. Targets - 100%
100% - As a clients knowledge of embodied carbon increases,
As a clients knowledge of embodied carbon increases,
assessments undertaken earlier in the design phase - become easier to commission and use for decisionmaking. This in turn will lead to increased opportunities
become easier to commission and use for decisionmaking. This in turn will lead to increased opportunities
to take action on reducing the embodied carbon - impact of projects and activities.
impact of projects and activities. - The embodied carbon and work stages (Table 1) is
The embodied carbon and work stages (Table 1) is
aligned with the carbon reduction curve (Figure 5).
66 Supporting Guidance: 9. Major wins - 100%
100% - Build nothing challenge the root cause of the need; explore
Build nothing challenge the root cause of the need; explore
alternative approaches to achieve the desired outcome - 80%
80% - Build less maximise the use of existing assets; optimise
Build less maximise the use of existing assets; optimise
asset operation and management to reduce the extent of new
construction required - 50%
50% - Build clever design in the use of low carbon materials;
Build clever design in the use of low carbon materials;
streamline delivery processes; minimise resource consumption - 20%
20% - Build efficiently embrace new construction technologies;
Build efficiently embrace new construction technologies; - eliminate waste
eliminate waste - 0%
0% - Pl
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e - 66 Supporting Guidance: 7. Benchmarks
66 Supporting Guidance: 7. Benchmarks - What to do with the outputs?
What to do with the outputs? - Carbon reduction potential
Carbon reduction potential - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Figure 5 Tackle carbon early more opportunities for reductions exist earlier in the construction process[27]
Figure 5 Tackle carbon early more opportunities for reductions exist earlier in the construction process[27]
Derwent London | 1 Page Street - EMBODIED CARBON: DEVELOPING A CLIENT BRIEF
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - Glossary
Glossary - 34 | 35
34 | 35 - 7. Glossary
7. Glossary - Boundary (or system boundary):An LCA
Boundary (or system boundary):An LCA
boundary determines which processes to be included - in the LCA study.
in the LCA study. - Boundaries and BS 15978:Embodied carbon
Boundaries and BS 15978:Embodied carbon - assessments often use the BS 15978:2011
assessments often use the BS 15978:2011
Sustainability of construction works Assessment - of environmental performance of buildings
of environmental performance of buildings - Calculation method.[28] This standard is a whole life
Calculation method.[28] This standard is a whole life
cycle assessment (LCA) standard. The standard splits
the lifecycle into 17 modules, each defining the source
of environmental impacts, including the sources - of embodied carbon[29]. These modules are then
of embodied carbon[29]. These modules are then
referenced to draw the embodied carbon boundary. - Carbon hotspot*:The carbon significant aspect
Carbon hotspot*:The carbon significant aspect
of a project which should be targeted for reduction.
Carbon hotspots represent not only carbon-intense - or high volume elements but also quick wins, where
or high volume elements but also quick wins, where
measurement data is more easily available and where - carbon reductions are possible.
carbon reductions are possible. - Capital Carbon:refers to emissions associated
Capital Carbon:refers to emissions associated - with the creation of an asset. Capital carbon is being
with the creation of an asset. Capital carbon is being
adopted within the infrastructure sector because - it accords with the concept of capital cost. (Going
it accords with the concept of capital cost. (Going
forward, the related term embodied carbon will - continue to be used at a product-level, whereas capital
continue to be used at a product-level, whereas capital
carbon will have greater relevance at an asset-level).[3]
CDP:Formerly known as the Carbon Disclosure Project,
this organisation works with corporations to disclose - their GHG emissions.
their GHG emissions. - Carbon emissions, CO2e, CO2eq, greenhouse gas
Carbon emissions, CO2e, CO2eq, greenhouse gas
emissions (GHGs):Shorthand terms for the emissions
of any of the number of greenhouse gases (GHGs)
that affect climate change. Carbon emissions are - usually expressed as CO2 equivalent (CO2e or CO2eq),
usually expressed as CO2 equivalent (CO2e or CO2eq),
which is a unit of measurement based on the relative
impact of a given gas on global warming over a given
time horizon i.e. the global warming potential (GWP).
For example, over a 100-year time horizon excluding
climate-carbon feedbacks, methane has a GWP of 28,
which means that 1 kg of methane would have the
same impact on climate change as 28 kg of carbon
dioxide and thus 1 kg of methane would count as 28
kg of CO2e. - Cradle-to-completed construction:an LCA
Cradle-to-completed construction:an LCA - system boundary which combines all emissions
system boundary which combines all emissions - from extraction, manufacturing and the transport of
from extraction, manufacturing and the transport of - materials to site together with the emissions generated
materials to site together with the emissions generated - during construction. This may or may not include
during construction. This may or may not include
emissions associated with supporting services, such as - design, worker travel to and from site etc.
design, worker travel to and from site etc.
Cradle-to-grave boundary:an LCA system - boundary term which combines all emissions up to
boundary term which combines all emissions up to - and including the end of life scenarios. It will include
and including the end of life scenarios. It will include
demolition emissions but the calculation will change - depending on what happens at the end of life.*
depending on what happens at the end of life.*
DJSI:The Dow Jones Sustainability Indices evaluate
the sustainability performance of the largest 2,500 - companies listed on the Dow Jones Global Total Stock
companies listed on the Dow Jones Global Total Stock
Market Index. - Environmental Product Declaration (EPD):An
Environmental Product Declaration (EPD):An - environmental product declaration is a verified and
environmental product declaration is a verified and - registered document that communicates transparent
registered document that communicates transparent - and comparable information about the life cycle
and comparable information about the life cycle - environmental impact of products.
environmental impact of products. - FTSEGood: The FTSE4Good Index Series is
FTSEGood: The FTSE4Good Index Series is - designed to measure the performance of companies
designed to measure the performance of companies - demonstrating strong Environmental, Social and
demonstrating strong Environmental, Social and - Governance (ESG) practices. Transparent management
Governance (ESG) practices. Transparent management - and clearly-defined ESG criteria make FTSE4Good
and clearly-defined ESG criteria make FTSE4Good - indexes suitable tools to be used by a wide variety
indexes suitable tools to be used by a wide variety
of market participants when creating or assessing - sustainable investment products.
sustainable investment products. - Greenhouse gas emissions (GHGs):A collection
Greenhouse gas emissions (GHGs):A collection
of gases that, when present in the atmosphere,
trap infrared radiation in the form of heat, causing a
warming process called the greenhouse effect. - Global Real Estate Sustainability Benchmark
Global Real Estate Sustainability Benchmark - (GRESB):An investor-driven benchmark for the
(GRESB):An investor-driven benchmark for the
environmental, social and governance performance of - real estate assets.
real estate assets. - Global warming potential (GWP):a relative measure of how much
Global warming potential (GWP):a relative measure of how much
a given mass of greenhouse gas is estimated to contribute to global
warming over a given time interval. It is expressed relative to carbon
dioxide which has a GWP of 1. These factors are regularly updated, and
it is recommended to use the latest factors from the Intergovernmental
Panel on Climate Change (IPCC). Most assessments adopt GWP factors
over a 100 year-time horizon. - GWP of principal greenhouse gases over 100 years excluding climatecarbon feedbacks[30]
GWP of principal greenhouse gases over 100 years excluding climatecarbon feedbacks[30]
Greenhouse Gas - GWP
GWP - Typical sources
Typical sources - Carbon dioxide (CO2)
Carbon dioxide (CO2) - 1
1 - Energy combustion, biochemical reactions
Energy combustion, biochemical reactions - Methane (CH4)
Methane (CH4) - 28
28 - Decomposition
Decomposition - Nitrous oxide (N2O)
Nitrous oxide (N2O) - 265
265 - Fertilisers, car emissions, manufacturing
Fertilisers, car emissions, manufacturing - Life Cycle Assessment (LCA):LCA is a technique by which to assess
Life Cycle Assessment (LCA):LCA is a technique by which to assess
the environmental impacts of a products life. This encompasses from raw
material extraction to disposal and can also include the recycling stage.
Operational Carbon*:Carbon emissions association with energy
consumption (operational energy) while the building is occupied. This
includes the regulated load (e.g. heating, cooling, ventilation, lighting)
and unregulated/plug load (e.g. ICT equipment, cooking, refrigeration
appliances). - RE100:RE100 is a collaborative, global initiative of influential businesses
RE100:RE100 is a collaborative, global initiative of influential businesses
committed to 100% renewable electricity, working to massively increase
demand for - and delivery of - renewable energy. Companies joining
RE100 are encouraged to set a public goal to procure 100% of their
electricity from renewable sources of energy by a specified year. RE100
was created by The Climate Group in partnership with CDP, as part of the
We Mean Business coalition. - Science Based Targets (SBT) Initiative:The Science Based Target
Science Based Targets (SBT) Initiative:The Science Based Target
initiative has been set up by CDP, The UN Global Compact, the World
Resources Institute and WWF to ensure that GHG reduction targets are
consistent with the pace recommended by climate scientists to limit the
worst impacts of climate change. - Whole life carbon:Another term for cradle-to-grave carbon emissions**.
Whole life carbon:Another term for cradle-to-grave carbon emissions**.
When referring to assets, whole life carbon usually refers to total
operational and embodied carbon emissions. - Walsh | Indescon Court
Walsh | Indescon Court - * For other boundary definitions, see the Supporting Guidance.
* For other boundary definitions, see the Supporting Guidance.
** Indicates the definition is based on RICS 2014 Global Guidance Methodology to calculate embodied carbon.
EMBODIED CARBON: DEVELOPING A CLIENT BRIEF - References
References - 36 | 37
36 | 37 - 8. References
8. References - 1.
1. - RICS, 2012. Methodology to calculate embodied
RICS, 2012. Methodology to calculate embodied - carbon of materials, 1st edition.
carbon of materials, 1st edition. - 2.
2. - WRAP, 2011. Cutting Embodied Carbon in Construction
WRAP, 2011. Cutting Embodied Carbon in Construction
Projects. - 3.
3. - HM Treasury, 2013. Infrastructure Carbon Review.
HM Treasury, 2013. Infrastructure Carbon Review.
Available at: https://www.gov.uk/government/ - publications/infrastructure-carbon-review
publications/infrastructure-carbon-review - 4.
4. - WRI Institute & WCSBD, 2001. The Greenhouse Gas
WRI Institute & WCSBD, 2001. The Greenhouse Gas
(GHG) Protocol Corporate Value Chain (Scope 3)
Accounting and Reporting Standard. Available at http://
www.ghgprotocol.org/standards/scope-3-standard - 5.
5. - UN-Habitat, 2015. Available at http://unhabitat.org/
UN-Habitat, 2015. Available at http://unhabitat.org/ - buildings-day-proves-a-hit-at-cop21/
buildings-day-proves-a-hit-at-cop21/ - 6.
6. - UN-FCCC, 2016. The Paris Agreement. Available at
UN-FCCC, 2016. The Paris Agreement. Available at
http://unfccc.int/paris_agreement/items/9485.php - 7.
7. - The Low Carbon Routemap encompasses both
The Low Carbon Routemap encompasses both - operational and embodied carbon emissions for the
operational and embodied carbon emissions for the - built environment sector. Available at http://www.
built environment sector. Available at http://www. - greenconstructionboard.org/otherdocs/Routemap%20
greenconstructionboard.org/otherdocs/Routemap%20 - final%20report%2005032013.pdf
final%20report%2005032013.pdf - 8.
8. - Based on data from the Green Construction Boards
Based on data from the Green Construction Boards - Low Carbon Routemap for the Built Environment: 2015
Low Carbon Routemap for the Built Environment: 2015
Routemap Progress - Technical Report. Available at:
http://greenconstructionboard.org/otherdocs/2015%20 - Built%20environment%20low%20carbon%20
Built%20environment%20low%20carbon%20
routemap%20progress%20report%202015-12-15.pdf - 9.
9. - HM Government, 2013. Construction 2025: Industrial
HM Government, 2013. Construction 2025: Industrial
Strategy: government and industry in partnership. - Available at: https://www.gov.uk/government/uploads/
Available at: https://www.gov.uk/government/uploads/ - system/uploads/attachment_data/file/210099/bis-13955-construction-2025-industrial-strategy.pdf
system/uploads/attachment_data/file/210099/bis-13955-construction-2025-industrial-strategy.pdf
10. Based on the 80% reduction scenario reported in
the 2013 Green Construction Board Low Carbon - Routemap. Data has been updated to the baseline
Routemap. Data has been updated to the baseline
reported in the Green Construction Boards Low - Carbon Routemap for the Built Environment 2015
Carbon Routemap for the Built Environment 2015 - Routemap Progress - Technical Report. Available at
Routemap Progress - Technical Report. Available at - http://greenconstructionboard.org/otherdocs/2015%20
http://greenconstructionboard.org/otherdocs/2015%20 - Built%20environment%20low%20carbon%20
Built%20environment%20low%20carbon%20
routemap%20progress%20report%202015-12-15.pdf - 11.
11. - The Water Services Regulation Authority (Ofwat).
The Water Services Regulation Authority (Ofwat).
12. Keil, M., Perry, H., Humphrey, J. & Holdway, R. (2013)
Understanding Embodied Greenhouse Gas Emissions - in the Water and Sewerage Sectors. Water and
in the Water and Sewerage Sectors. Water and
Environment Journal, 27 (2), pp. 253260. Available
from: http://doi.wiley.com/10.1111/wej.12001 - 13. RICS Professional Guidance, 2014. Methodology to
13. RICS Professional Guidance, 2014. Methodology to
calculate embodied carbon of materials. 1st edition.
Available at: http://www.rics.org/Global/Methodology_ - to_calculate_embodied_carbon_1st_edition_
to_calculate_embodied_carbon_1st_edition_ - PGguidance_2014.pdf
PGguidance_2014.pdf - 14. An ambitious and measureable Scope 3 target with a
14. An ambitious and measureable Scope 3 target with a
clear time-frame is required when Scope 3 emissions - cover a significant portion (greater than 40% of
cover a significant portion (greater than 40% of
total scope 1, 2 and 3 emissions) of a companys
overall emissions. The target boundary must include - the majority of value chain emissions as defined by
the majority of value chain emissions as defined by
the GHG Protocol Corporate Value Chain (Scope - 3) Accounting and Reporting Standard (e.g. top 3
3) Accounting and Reporting Standard (e.g. top 3
categories, or 2/3 of total scope 3 emissions). Web:
sciencebasedtargets.com, 2016 - 15. Trucost, Oct 2016. More Carbon Disclosure and Target
15. Trucost, Oct 2016. More Carbon Disclosure and Target
Setting in North America, but are Companies Focused
on What Matters Most - 16. Scope 3 emissions in this context are scope 1, 2 and 3
16. Scope 3 emissions in this context are scope 1, 2 and 3
emissions from the development process. - 17.
17. - GRESB sections include Environmental attributes
GRESB sections include Environmental attributes - of building materials, Location and transport and
of building materials, Location and transport and - Specification and purchasing of rapidly renewable
Specification and purchasing of rapidly renewable - materials, low embodied carbon materials, and
materials, low embodied carbon materials, and - recycled content materials. It also has a section on
recycled content materials. It also has a section on
the percentage of real estate assets which have - a certification. The potential for embodied carbon
a certification. The potential for embodied carbon - certification for listed property companies may become
certification for listed property companies may become - more important.
more important. - 22. BSI, 2016. PAS 2080:2016, Carbon Management in
22. BSI, 2016. PAS 2080:2016, Carbon Management in
Infrastructure. Available at http://shop.bsigroup.com/ - forms/PASs/PAS-2080/
forms/PASs/PAS-2080/ - 27.
27. - 23. There are various assessment standards for GHG
23. There are various assessment standards for GHG
emissions at corporate levels which are covered in - Section 3.5 however, these are generally considered
Section 3.5 however, these are generally considered - suitable for organisational emissions but not for
suitable for organisational emissions but not for - embodied carbon assessments at a built asset level.
embodied carbon assessments at a built asset level.
28. PAS 2080 can also be used. It presents modules
covering all impacts for infrastructure projects. - 24. prEN 15643-5:2016 is currently a draft standard.
24. prEN 15643-5:2016 is currently a draft standard.
Publication is due 25th October 2017 - 25. RICS Professional Guidance, Global. Methodology to
25. RICS Professional Guidance, Global. Methodology to
calculate embodied carbon of materials. 1st edition,
2014. Available from: http://www.rics.org/Global/ - Methodology_to_calculate_embodied_carbon_1st_
Methodology_to_calculate_embodied_carbon_1st_ - edition_PGguidance_2014.pdf
edition_PGguidance_2014.pdf - 26. WRAP, 2017. Embodied Carbon Database. Available at
26. WRAP, 2017. Embodied Carbon Database. Available at
http://ecdb.wrap.org.uk/ - 18. The social cost of carbon (SCC) measures the full cost
18. The social cost of carbon (SCC) measures the full cost
of an incremental unit of carbon (or greenhouse gas
equivalent) emitted now, calculating the full cost of the
damage it imposes over the whole of its time in the
atmosphere. Because the amount of damage caused - by each incremental unit of carbon in the atmosphere
by each incremental unit of carbon in the atmosphere
depends on the concentration of atmospheric carbon - today and in the future, the SCC varies according to the
today and in the future, the SCC varies according to the
emissions and concentration trajectory the world is on.
HM Government. Social Cost of Carbon. Available
from: https://www.gov.uk/government/collections/ - carbon-valuation2#social-cost-of-carbon
carbon-valuation2#social-cost-of-carbon - 19. RICS use the term carbon critical to indicate essential
19. RICS use the term carbon critical to indicate essential
elements that will have a high contribution to the
overall carbon footprint be that because they are - particularly carbon intense or simply used in large
particularly carbon intense or simply used in large - volume. See Table 3 in the RICS 2014 methodology for
volume. See Table 3 in the RICS 2014 methodology for
a suggested set of carbon critical hotspots. Available
from: http://www.rics.org/Global/Methodology_ - to_calculate_embodied_carbon_1st_edition_
to_calculate_embodied_carbon_1st_edition_ - PGguidance_2014.pdf
PGguidance_2014.pdf - 20. PAS 2080 may be useful for larger clients where
20. PAS 2080 may be useful for larger clients where
there are multiple actors. PAS 2080 is written for
infrastructure projects, however, it is easily adapted to
buildings. - 21.
21. - If the embodied carbon assessment is commissioned
If the embodied carbon assessment is commissioned - at handover, without prior commissioning of embodied
at handover, without prior commissioning of embodied - carbon data gathering at the start of the project, it is
carbon data gathering at the start of the project, it is
unlikely that a complete data set for an assessment will
be available. - Walsh | Hawley School
Walsh | Hawley School - HM Treasury, 2013. Infrastructure Carbon Review.
HM Treasury, 2013. Infrastructure Carbon Review.
Available at: https://www.gov.uk/government/ - publications/infrastructure-carbon-review
publications/infrastructure-carbon-review - 29. With the exception of Module B6 which is exclusively
29. With the exception of Module B6 which is exclusively
operational energy use and module B7 which - considers operational water use
considers operational water use - 30. IPCC, 2013. Climate Change 2013: The Physical Science
30. IPCC, 2013. Climate Change 2013: The Physical Science
Basis. Contribution of Working Group 1 to the Fifth
Assessment Report of the Intergovernmental Panel on - Climate Change, Table 8.7. Available from: http://www.
Climate Change, Table 8.7. Available from: http://www.
climatechange2013.org/images/report/WG1AR5_ALL_ - FINAL.pdf
FINAL.pdf - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 38
38 - Embodied Carbon:
Embodied Carbon: - Supporting Guidance
Supporting Guidance - Introduction
Introduction - 39
39 - 1. Introduction
1. Introduction - The Supporting Guidance complements the information provided previously and acts as a springboard for
The Supporting Guidance complements the information provided previously and acts as a springboard for
further research. The Supporting Guidance is not designed to be read sequentially. Each section can be read
independently. It signposts to existing resources frequently used in industry and provides short explanations
where necessary. - The Supporting Guidance references many resources which use life cycle assessment (LCA) as the main approach
The Supporting Guidance references many resources which use life cycle assessment (LCA) as the main approach
as opposed to solely embodied carbon assessment, which is one of multiple impacts measured within an LCA.
Contents - 1.
1. - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 41
41 - 2. What is the technical basis for identifying life cycle stages?
2. What is the technical basis for identifying life cycle stages?
2. What is the technical basis for identifying life cycle stages?
41 - 3. Standards and industry reference documents
3. Standards and industry reference documents - 42
42 - Assets or products have environmental impacts throughout their whole life. LCA provides an approach to
Assets or products have environmental impacts throughout their whole life. LCA provides an approach to
understand and measure these impacts at each life cycle stage. All LCAs require boundaries to be defined
(system boundaries), which reflect the life cycle stages and processes. For example, whether the environmental
impacts associated with the manufacturing of the site plant need to be included or not.
3.1 - Presenting LCA results in a structured format
Presenting LCA results in a structured format - 43
43 - 4. Calculation methodologies, data and tools
4. Calculation methodologies, data and tools
45 - a) BS EN ISO 14040:2006 Environmental management. Life cycle assessment. Principles and framework; and
a) BS EN ISO 14040:2006 Environmental management. Life cycle assessment. Principles and framework; and
45 - 47
47 - 48
48 - b) BS EN ISO 14044:2006 Environmental management. Life cycle assessment. Requirements and guidelines.
b) BS EN ISO 14044:2006 Environmental management. Life cycle assessment. Requirements and guidelines.
4.1 - 4.2
4.2 - 4.3
4.3 - Data
Data - Methodologies
Methodologies - Tools
Tools - 5. Whole built asset level assessment methodologies requirements for embodied carbon 49
5. Whole built asset level assessment methodologies requirements for embodied carbon 49
5.1 - 5.2
5.2 - 5.3
5.3 - 5.4
5.4 - 5.5
5.5 - 5.6
5.6 - BREEAM
BREEAM - The Home Quality Mark (HQM)
The Home Quality Mark (HQM) - LEED v4
LEED v4 - Ska
Ska - CEEQUAL v5
CEEQUAL v5 - BREEAM Infrastructure
BREEAM Infrastructure - 49
49 - 50
50 - 50
50 - 51
51 - 51
51 - 52
52 - 6. Setting up meaningful comparisons
6. Setting up meaningful comparisons - 52
52 - 7.
7. - 52
52 - Benchmarks
Benchmarks - 8. Targets
8. Targets - 8.1
8.1 - 8.2
8.2 - 8.3
8.3 - Comparative targets
Comparative targets - Intensity targets
Intensity targets - Absolute reduction targets
Absolute reduction targets - Embodied carbon measurement is included in the calculation method for evaluating the environmental
Embodied carbon measurement is included in the calculation method for evaluating the environmental
performance of built assets, as set out in the European standard, BS EN 15978:2011 Sustainability of
construction works Assessment of environmental performance of buildings. BS 15978 uses a modular
approach, in which each life cycle stage is assessed separately. (Guidance Figure 1)
The interaction between these standards (and others) is detailed in Section 3.
Cradle-to-cradle - Cradle-to-grave
Cradle-to-grave - Cradle-to-completed construction
Cradle-to-completed construction - Cradle-to-gate
Cradle-to-gate - 53
53 - 53
53 - 53
53 - 53
53 - 9. Major wins
9. Major wins - 53
53 - 10. Other key documents
10. Other key documents - 54
54 - 11. Other Example client briefs
11. Other Example client briefs - 55
55 - 11.1 British Land, Draft Embodied Carbon Scope
11.1 British Land, Draft Embodied Carbon Scope
11.2 Derwent London, Embodied Carbon Brief - 11.3 HS2, EIA Scope and Methodology
11.3 HS2, EIA Scope and Methodology - LCA practice is governed by the following international standards, which provide guidance on life cycle stages:
LCA practice is governed by the following international standards, which provide guidance on life cycle stages:
55 - 58
58 - 61
61 - A1 to A3
A1 to A3 - Extraction
Extraction - to Production
to Production - Raw material
Raw material - supply A1
supply A1 - Transport A2
Transport A2 - Manufacturing A3
Manufacturing A3 - A 4 to A5
A 4 to A5 - Construction
Construction - B1 to B5
B1 to B5 - Use
Use - Transport A4
Transport A4 - Use B1
Use B1 - Construction
Construction - installation
installation - process A5
process A5 - Maintenance B2
Maintenance B2 - Repair B3
Repair B3 - Replacement B4
Replacement B4 - Refurbishment B5
Refurbishment B5 - C1 to C4
C1 to C4 - End-of-life
End-of-life - Deconstruction
Deconstruction - demolition C1
demolition C1 - Transport C2
Transport C2 - Waste
Waste - processing C3
processing C3 - Disposal C4
Disposal C4 - Guidance Figure 1 LCA information modules for the construction sector (BRE)
Guidance Figure 1 LCA information modules for the construction sector (BRE)
D - Benefits and
Benefits and - loads beyond
loads beyond - system
system - boundaries
boundaries - Reuse,
Reuse, - recovery,
recovery, - recycling D
recycling D - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 40
40 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 41
41 - The various life cycle stages commonly referred to are:
The various life cycle stages commonly referred to are:
Standards - Description
Description - i.
i. - BS EN 15978:2011 Sustainability of construction works Assessment of environmental performance of buildings.
BS EN 15978:2011 Sustainability of construction works Assessment of environmental performance of buildings.
Calculation method. - This standard specifies the calculation method, based
This standard specifies the calculation method, based - on LCA to assess the environmental performance of a
on LCA to assess the environmental performance of a
building. It also provides guidance on the reporting and
communication of the outcome of the assessment. This
standard is relevant to all building types, new and existing.
pr EN 15643-5 Sustainability of Construction Works Sustainability Assessment of Buildings and Civil Engineering
Works - Part 5: Framework for the Assessment of
Sustainability Performance of Civil Engineering Works. (In
development). - This standard is still in development, but will aim to
This standard is still in development, but will aim to
provide the specific principles and requirements for - the assessment of environmental performance of civil
the assessment of environmental performance of civil - engineering works.
engineering works. - Cradle -to-gate (A1 to A3): from resource extraction to the factory gate, covering the manufacture of the
Cradle -to-gate (A1 to A3): from resource extraction to the factory gate, covering the manufacture of the
respective construction products and materials; - *
* - ii. Cradle-to-site (A1 to A4): cradle-to-gate, plus the delivery of the products to site;
ii. Cradle-to-site (A1 to A4): cradle-to-gate, plus the delivery of the products to site;
iii. Cradle-to-completed construction (A1 to A5): cradle-to-site, plus the actual construction phase or the process
of installing the product in the built asset;
iv. Cradle-to-grave (A1 to C4): cradle-to-completed construction, plus the use of the products in the built asset,
the use of the built asset itself, the end of life processes covering demolition and final disposal;
v. Cradle-to-cradle (A1 to C4 and beyond): this is essentially a cradle-to-grave study that further evaluates
the reuse of the product, parts of the built asset, or all of the built asset in a new life; this terminology is
associated with a circular economy approach. - In addition, Cradle-to-transfer of ownership could be used in situations where clients wish to build, operate,
In addition, Cradle-to-transfer of ownership could be used in situations where clients wish to build, operate,
maintain and then sell. It would cover modules A1-A5, B1-B5.
3. Standards and industry reference documents - There are a number of standards and guidance covering LCA. These can be categorised as:
There are a number of standards and guidance covering LCA. These can be categorised as:
international standards which define an overall framework and set out the overarching principles of LCA for
all sectors - sector-specific standards, which build on the standards above, and are specifically relevant to the built
sector-specific standards, which build on the standards above, and are specifically relevant to the built
environment. Many of these focus on the quantification or reporting of impacts at either the product or asset
level. - Guidance Table 1 Standards (LCA and sector-specific)
Guidance Table 1 Standards (LCA and sector-specific)
Standards - Description
Description - Overall framework standards for life cycle assessment
Overall framework standards for life cycle assessment - BS EN ISO 14040:2006 Environmental management. Life
BS EN ISO 14040:2006 Environmental management. Life - cycle assessment. Principles and framework.
cycle assessment. Principles and framework. - This standard describes the principles and framework
This standard describes the principles and framework - to carry out life cycle assessment (LCA), including goal
to carry out life cycle assessment (LCA), including goal
and scope definition, inventory, impact assessment,
interpretation and reporting. - BS EN ISO 14044:2006 Environmental management. Life
BS EN ISO 14044:2006 Environmental management. Life - cycle assessment. Requirements and guidelines.
cycle assessment. Requirements and guidelines. - This standard specifies requirements and provides
This standard specifies requirements and provides - guidelines to carry out life cycle assessment (LCA) studies.
guidelines to carry out life cycle assessment (LCA) studies.
International standards for built assets and construction products - BS ISO 21931:2010 Sustainability in building construction.
BS ISO 21931:2010 Sustainability in building construction. - Framework for methods of assessment of the
Framework for methods of assessment of the - environmental performance of construction works.
environmental performance of construction works. - Buildings.
Buildings. - This standard provides a general framework for improving
This standard provides a general framework for improving - the quality and comparability of methods for assessing
the quality and comparability of methods for assessing - the environmental performance of built assets.
the environmental performance of built assets. - BS ISO 21930:2007 Sustainability in building construction
BS ISO 21930:2007 Sustainability in building construction - Environmental declaration of building products (EPDs).
Environmental declaration of building products (EPDs).
This standard provides the principles and requirements - for Environmental Product Declaration (EPD) of building
for Environmental Product Declaration (EPD) of building
products. - BS EN 15804:2012+A1:2013 Sustainability of construction
BS EN 15804:2012+A1:2013 Sustainability of construction
works. Environmental product declarations. Core rules for
the product category of construction products. - This standard provides core rules for EPD for construction
This standard provides core rules for EPD for construction
products and services. - BS = British Standard/UK only
BS = British Standard/UK only - EN = European standard
EN = European standard - ISO = International standard
ISO = International standard - Carbon specific standards
Carbon specific standards - In addition to LCA standards which cover a broad range of environmental impacts, a number of standards
In addition to LCA standards which cover a broad range of environmental impacts, a number of standards
specifically address carbon emissions. - BSI, the UK national standards body, has developed a publicly available specification (PAS) specifically for carbon
BSI, the UK national standards body, has developed a publicly available specification (PAS) specifically for carbon
assessment, PAS 2050:2011 Specification for the assessment of the life cycle greenhouse gas emissions of
goods and services. PAS 2050 builds on the international LCA standards and provides guidance on how to
calculate the carbon footprint of goods and services for all sectors. Products can be certified against this standard.
BSI has also published PAS 2080:2016 Carbon management in infrastructure, which aims to help all members
of the infrastructure value chain understand and manage carbon associated with the development of
infrastructure assets from cradle-to-grave. Although written for infrastructure, it is possible to adapt this process
to buildings. Companies can be accredited to this specification.
Through the GHG Protocol partnership, The World Resources Institute (WRI) and the World Business Council
for Sustainable Development (WBCSD) have published a range of city, corporate and product greenhouse gas
accounting and reporting standards*. The embodied carbon of built assets is included within the Corporate Value
Chain (Scope 3) Accounting and Reporting Standard which acts as a supplement to the widely used Corporate
Accounting and Reporting Standard. - 3.1
3.1 - Presenting LCA results in a structured format
Presenting LCA results in a structured format - There are several standards that guide the user on the reporting and communication of the results of an LCA.
There are several standards that guide the user on the reporting and communication of the results of an LCA.
Guidance Table 2 Standards (LCA reporting and communication)
European standards for built assets - BS EN 15643-2:2011 Sustainability of construction works
BS EN 15643-2:2011 Sustainability of construction works
Assessment of buildings. Part 2: Framework for the
assessment of environmental performance. - European standards for construction products
European standards for construction products - This standard provides the specific principles and
This standard provides the specific principles and - requirements for the assessment of environmental
requirements for the assessment of environmental - performance of buildings taking into account technical
performance of buildings taking into account technical - characteristics and functionality of a building. This
characteristics and functionality of a building. This - standard is relevant to all building types, new and existing.
standard is relevant to all building types, new and existing.
* - The term cradle refers to the extraction stage of the primary resources of any product.
The term cradle refers to the extraction stage of the primary resources of any product.
Use - Title
Title - Description
Description - Reporting and
Reporting and - communication of LCA
communication of LCA - results.
results. - BS EN ISO 14025:2010 Environmental
BS EN ISO 14025:2010 Environmental - labels and declarations. Type III
labels and declarations. Type III - environmental declarations. Principles and
environmental declarations. Principles and - procedures.
procedures. - This standard establishes the principles and
This standard establishes the principles and - specifies the procedures for developing
specifies the procedures for developing - EPDs. This standard requires that the LCA
EPDs. This standard requires that the LCA - study has been carried out in accordance
study has been carried out in accordance - with relevant LCA standards referenced
with relevant LCA standards referenced - earlier.
earlier. - Reporting and
Reporting and - communication of LCA
communication of LCA - results for construction
results for construction - products.
products. - BS EN 15942:2011 Sustainability of
BS EN 15942:2011 Sustainability of - construction works. Environmental
construction works. Environmental - product declarations. Communication
product declarations. Communication - format business-to-business.
format business-to-business. - The aim of this standard is to harmonise
The aim of this standard is to harmonise - the way in which EN 15804 compliant
the way in which EN 15804 compliant - EPDs are communicated in Europe.
EPDs are communicated in Europe. - *
* - For a full list of GHG Protocol standards see: http://ghgprotocol.org/standards
For a full list of GHG Protocol standards see: http://ghgprotocol.org/standards
EMBODIED CARBON: SUPPORTING GUIDANCE - 42
42 - Use
Use - Title
Title - Description
Description - Reporting and
Reporting and - communication of embodied
communication of embodied - (and operational) carbon
(and operational) carbon - studies of products and
studies of products and - factories/ organisations.
factories/ organisations. - BS EN ISO 14064-2:2012 Greenhouse
BS EN ISO 14064-2:2012 Greenhouse - gases. Specification with guidance at the
gases. Specification with guidance at the - project level for quantification, monitoring
project level for quantification, monitoring - and reporting of greenhouse gas emission
and reporting of greenhouse gas emission - reductions or removal enhancements..
reductions or removal enhancements.. - This standard provides guidance on the
This standard provides guidance on the - quantification, monitoring and reporting
quantification, monitoring and reporting - of activities which cause greenhouse gas
of activities which cause greenhouse gas - (GHG) emissions at project level.
(GHG) emissions at project level. - ISO/TS 14067:2013 Greenhouse
ISO/TS 14067:2013 Greenhouse - gases Carbon footprint of products
gases Carbon footprint of products - Requirements and guidelines for
Requirements and guidelines for - quantification and communication.
quantification and communication. - A technical specification which details the
A technical specification which details the - principles, requirements and guidelines
principles, requirements and guidelines - for the quantification and communication
for the quantification and communication - of the carbon footprint of products (both
of the carbon footprint of products (both - goods and services).
goods and services). - 4. Calculation methodologies, data and tools
4. Calculation methodologies, data and tools - Infrastructure
Infrastructure - Building
Building - Built asset level
Built asset level - European
European - European/International
European/International - UK and Carbon only
UK and Carbon only - prEN 15643-5
prEN 15643-5 - BS EN ISO
BS EN ISO - 14064-2:2012
14064-2:2012 - PAS
PAS - 2080:2016
2080:2016 - Data
Data - The following is a selection of data and data sources. All of these are the results of LCA studies which have been
The following is a selection of data and data sources. All of these are the results of LCA studies which have been
done at construction product or element level. These individual results can then be used within a whole built
asset assessment. - There are two types of EPDs available:
There are two types of EPDs available: - Proprietary EPDs - these cover products from a specific manufacturer;
Proprietary EPDs - these cover products from a specific manufacturer;
Generic EPDs - these typically cover a product type and are created by a group of manufacturers.
EPDs are based on manufacturing data and, for the construction industry, should comply with either ISO 21930
(international) or EN 15804 (Europe).
BS EN - 15978:2011
15978:2011 - EPDs are verified and published by established EPD programme operators according to the requirements of ISO
EPDs are verified and published by established EPD programme operators according to the requirements of ISO
14025. Examples of EPD sources include: - BS EN ISO
BS EN ISO - 21930:2007
21930:2007 - Product level
Product level - 4.1
4.1 - Environmental Product Declarations (EPDs)
Environmental Product Declarations (EPDs) - under
under - development
development - BS EN ISO
BS EN ISO - 21931:2010
21931:2010 - To aid the calculation of embodied impacts of built assets, a number of methodologies and tools have been
To aid the calculation of embodied impacts of built assets, a number of methodologies and tools have been
derived and published complementary to the standards referenced above. These methodologies provide a
how-to set of instructions reflecting the focus or bias of respective sources. Datasets have been developed with
the aim of providing robust sources of data for assessments and calculations. Below is a non-exhaustive list of
examples of data sources (and datasets), methodologies and tools are given below.
LCA studies for built assets use a variety of data sources. Some sources are free and publically available; others
are only available through specific tools. - Guidance Figure 2 provides an overview of the standards landscape.
Guidance Figure 2 provides an overview of the standards landscape.
International - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - soon to be
soon to be - updated
updated - BS EN
BS EN - 15804:2012
15804:2012 - + A1:2013
+ A1:2013 - BS EN
BS EN - 15942:2011
15942:2011 - ISO/TS
ISO/TS - 14067:2013
14067:2013 - PAS
PAS - 2050:2011
2050:2011 - BRE Globals EPD programme publishes its verified EPDs on BREs Green Book Live website:
BRE Globals EPD programme publishes its verified EPDs on BREs Green Book Live website:
http://www.greenbooklive.com/search/scheme.jsp?id=272 - ECO Platform, an association of European EPD programmes and stakeholders, provides a listing service for
ECO Platform, an association of European EPD programmes and stakeholders, provides a listing service for
EN 15804 compliant EPDs generated by its members:
http://eco-platform.org/list-of-all-eco-epd.html - In 2010 the CPA collated a number of international EPD sources. This is reproduced in Guidance Figure 3.
In 2010 the CPA collated a number of international EPD sources. This is reproduced in Guidance Figure 3.
BS EN ISO - 14025:2010
14025:2010 - CESMM4 Carbon and Price Book 2013 Mott Macdonald
CESMM4 Carbon and Price Book 2013 Mott Macdonald
LCA Framework - BS EN ISO 14040:2006 | BS EN ISO 14044:2006 | BS EN 15643-2:2011 (EU only)
BS EN ISO 14040:2006 | BS EN ISO 14044:2006 | BS EN 15643-2:2011 (EU only)
Focused on civil engineering*. This book includes carbon values (provided by BRE and therefore will give results
similar to the Green Guide to Specification) alongside costs. Data is reported in kgCO2e per unit for all materials
and processes. - Greenhouse Gas Protocol
Greenhouse Gas Protocol - Key
Key - Standard
Standard - Derived from
Derived from - Specification
Specification - Works in conjunction
Works in conjunction - Construction specific
Construction specific - Guidance Figure 2 Overview of the LCA related standards
Guidance Figure 2 Overview of the LCA related standards
* - CESMM4 Carbon and Price Book has been compiled using the latest update of the Civil Engineering Standard Method of Measurement (CESMM4). Available
CESMM4 Carbon and Price Book has been compiled using the latest update of the Civil Engineering Standard Method of Measurement (CESMM4). Available
at: http://www.rics.org/uk/shop/CESMM4-CarbonPrice-Book-2013-19402.aspx - 43
43 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 44
44 - NORWAY
NORWAY - EPD -Norge *
EPD -Norge * - www.epd-norge.no
www.epd-norge.no - BELGIUM
BELGIUM - Materials LCA tool: ecolizer 2.0
Materials LCA tool: ecolizer 2.0 - www.ovam.be
www.ovam.be - EPD Schemes
EPD Schemes - Generic Databases
Generic Databases - The Green Guide to Specification
The Green Guide to Specification - The Green Guide to Specification is based on the BRE Environmental Profiles Methodology and results are based
The Green Guide to Specification is based on the BRE Environmental Profiles Methodology and results are based
on generic data from UK industry. The Green Guide is maintained as an online resource. It is not envisaged that
there will be an update to the Green Guide beyond 2021, as BRE is moving towards a whole building level
assessment (see IMPACT section below). - LCA Tools
LCA Tools - NETHERLANDS
NETHERLANDS - PCR: NEN 8006: 2004
PCR: NEN 8006: 2004 - EPDs: MRPI www.mrpi.nl
EPDs: MRPI www.mrpi.nl - UK
UK - PCR: Environmental Profiles (1999, 2007)
PCR: Environmental Profiles (1999, 2007)
EPDs: Environmental Profiles - www.greenbooklive.com
www.greenbooklive.com - SWEDEN/EUROPE
SWEDEN/EUROPE - Environdec *
Environdec * - www.environdec.com
www.environdec.com - Construction LCA database:
Construction LCA database: - SBK nationale
SBK nationale - milieudatabase
milieudatabase - www.bouwkwaliteit.nl/index2.
www.bouwkwaliteit.nl/index2. - php?id=55
php?id=55 - Generic construction LCA data:
Generic construction LCA data: - Environmental Profiles Database
Environmental Profiles Database - www.bre.co.uk
www.bre.co.uk - Envest2: envest2.bre.co.uk
Envest2: envest2.bre.co.uk - Green Guide to Specification:
Green Guide to Specification: - www.bre.co.uk/greenguide
www.bre.co.uk/greenguide - The Green Guide gives LCA results for building elements. Some elements are only formed of a single product,
The Green Guide gives LCA results for building elements. Some elements are only formed of a single product,
such as floor covering, insulation and windows. Other elements combine several products together e.g. an
external wall, which includes insulation, brick, blocks and plasterboard.
FINLAND - RT Environmental
RT Environmental - Declarations
Declarations - www.rts.fi
www.rts.fi - GPR Gebauw
GPR Gebauw - www.gprgebouw.nl
www.gprgebouw.nl - Greencalc+
Greencalc+ - www.greencalc.com
www.greencalc.com - Each element is given a rating from A+ to E based on an overall Ecopoint* score (derived from the LCA results).
Each element is given a rating from A+ to E based on an overall Ecopoint* score (derived from the LCA results).
The Green Guide also reports the kgCO2e/m2 from cradle-to-grave over a 60-year study period.
DENMARK - EPD: By og Byg
EPD: By og Byg - www.sbi.dk
www.sbi.dk - FRANCE
FRANCE - PCR: NF P01 - 010 2004
PCR: NF P01 - 010 2004 - EPD: Fiche de Declaration
EPD: Fiche de Declaration - Environmentale et Sanitaire (FDES)
Environmentale et Sanitaire (FDES) - www.inies.fr
www.inies.fr - Elodie: www.elodie -cstb.fr/
Elodie: www.elodie -cstb.fr/ - Building level LCA tool
Building level LCA tool - CATALONIA (Spain )
CATALONIA (Spain ) - EPDs: Declaraci Ambiental de
EPDs: Declaraci Ambiental de - Productes de la construcci
Productes de la construcci - (DAPc)
(DAPc) - es.csostenible.net/sistema_dapc/
es.csostenible.net/sistema_dapc/ - es/productos_dapc.php
es/productos_dapc.php - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - The Inventory of Carbon and Energy (ICE) Database
The Inventory of Carbon and Energy (ICE) Database
GERMANY - PCR: IBU
PCR: IBU - EPDs: IBU
EPDs: IBU - bau -umwelt.de
bau -umwelt.de - The database was developed by the University of Bath as a research project and the current version was last
The database was developed by the University of Bath as a research project and the current version was last
updated in 2011. The ICE Database holds data, sourced from a large literature review, for the most commonly
used products in construction. The database uses a combination of industry averages of materials and values
from studies available at the time (this includes some non-UK sources). Cradle-to-gate carbon values are
expressed in kgCO2 or kgCO2e and MJ. Other third party databases can be selected from the following source:
http://www.ghgprotocol.org/Third-Party-Databases - kobau.datLCA database
kobau.datLCA database - http://www.nachhaltigesbauen.de/
http://www.nachhaltigesbauen.de/ - baustoff -undgebaeudedaten/oekobaudat.html
baustoff -undgebaeudedaten/oekobaudat.html - It is worth noting that, depending on the data and data sources used, the results of LCA studies for whole built
It is worth noting that, depending on the data and data sources used, the results of LCA studies for whole built
assets may vary. Despite the common principles defined by the framework standards, there are variations in how
they are interpreted. This must be kept in mind when comparing results.
66 Section 6. Setting up meaningful comparisons - GaBi Build-it:
GaBi Build-it: - www.pe-international.com
www.pe-international.com - AUSTRIA
AUSTRIA - PCR : IBO REFERENZDATENBANK
PCR : IBO REFERENZDATENBANK - Data quality
Data quality - SWITZERLAND
SWITZERLAND - Generic construction LCA
Generic construction LCA - data: www.ecoinvent.ch
data: www.ecoinvent.ch - Generic construction LCA data:
Generic construction LCA data: - www.ibo.at/de/oekokennzahlen.htm
www.ibo.at/de/oekokennzahlen.htm - Different sources of data used to carry out an LCA are not all of the same quality. Quality is defined as:
Different sources of data used to carry out an LCA are not all of the same quality. Quality is defined as:
Lesosai: - Ecosoft: www.ibo.at/de/ecosoft.htm
Ecosoft: www.ibo.at/de/ecosoft.htm - the robustness of the process used to gather the data;
the robustness of the process used to gather the data;
the compliance with standards (Section 3. Standards and industry reference documents);
the relevance (geographical and product specific); and
the age of the data. - www.lesosai.com
www.lesosai.com - European Union
European Union - CEN TC350
CEN TC350 - www.cen.eu
www.cen.eu - European Union
European Union - ELCD
ELCD - lca.jrc.ec.europa.eu/
lca.jrc.ec.europa.eu/ - lcainfohub/index.vm
lcainfohub/index.vm - European Union
European Union - CAPEM
CAPEM - www.capem.eu
www.capem.eu - Europe
Europe - ESUCO LCA
ESUCO LCA - database (2011)
database (2011) - www.dgnb.de
www.dgnb.de - European Union
European Union - CILECCTA
CILECCTA - www.cileccta.eu
www.cileccta.eu - Guidance Figure 3 National EPD schemes with the Product Category Rules the schemes use and links
Guidance Figure 3 National EPD schemes with the Product Category Rules the schemes use and links
to those EPD for construction products that have been published. Includes the generic databases of
LCA or LCI data for construction products and building level LCA tools available across Europe*
Documents such as Construction Scope 3 (Embodied) Greenhouse Gas Accounting and Reporting Guidance
provide guidance on data quality. - 4.2
4.2 - Methodologies
Methodologies - Several methodologies exist to implement principles laid out in LCA standards. They can be used to calculate
Several methodologies exist to implement principles laid out in LCA standards. They can be used to calculate
embodied impacts of built assets. They are also implemented within various tools (See Section 4.3). The most
commonly cited methodologies available are: - 1503
1503 - 617
617 - 318
318 - 420
420 - IBU (Germany)
IBU (Germany) - EPDTurkey
EPDTurkey - EPD Danmark (Denmark)
EPD Danmark (Denmark) - 71
71 - 101
101 - UL Environment (USA)*
UL Environment (USA)* - International EPD(R) (Sweden)**
International EPD(R) (Sweden)**
SCS Global Services (USA) - 268
268 - 61
61 - Inies FDES (France) (2014 estimate)
Inies FDES (France) (2014 estimate)
BRE Verified EN 15804 EPD (UK) - Australasian EPD
Australasian EPD - DAPHabitat (Portugal)
DAPHabitat (Portugal) - EPD Norge (Norway)
EPD Norge (Norway) - Global EPD (Spain)
Global EPD (Spain) - Bau EPD (Austria)
Bau EPD (Austria) - ZAG EPD (Slovenia)
ZAG EPD (Slovenia) - ITB-EPD (Poland)
ITB-EPD (Poland) - DAPconstruccin (Spain)
DAPconstruccin (Spain) - EPD Italy
EPD Italy - EPDLatin America (Latin America)
EPDLatin America (Latin America) - RICS Methodology to calculate embodied carbon
RICS Methodology to calculate embodied carbon - This guidance builds on BS 15978 and sets out how to calculate the impacts for each life cycle stage. It also
This guidance builds on BS 15978 and sets out how to calculate the impacts for each life cycle stage. It also
provides background information to estimate the carbon emissions associated with construction projects
from cradle-to-grave. This document also provides carbon reduction strategies.
* - Aizlewood, C et al., 2007. Environmental weightings - their use in the environmental assessment of construction products. BRE, Watford. Available at https://
Aizlewood, C et al., 2007. Environmental weightings - their use in the environmental assessment of construction products. BRE, Watford. Available at https://
www.brebookshop.com/details.jsp?id=287511 - Guidance Figure 4 Which EPD Programmes publish verified EN 15804 EPD and how many are there now?
Guidance Figure 4 Which EPD Programmes publish verified EN 15804 EPD and how many are there now?
- Greater London Authority (GLA), 2013. Construction Scope 3 (Embodied): Greenhouse Gas Accounting and Reporting Guidance. Available at: https://www.
Greater London Authority (GLA), 2013. Construction Scope 3 (Embodied): Greenhouse Gas Accounting and Reporting Guidance. Available at: https://www.
london.gov.uk/sites/default/files/gla_construction_scope_3_embodied_greenhouse_gas_accounting_and_reporting_guidance_vfinal_1.pdf (See Table 7.2, - pp.27-28)
pp.27-28) - *
* - CPA, 2010. A guide to understanding the embodied impacts of construction products. Correct as at 2010.
CPA, 2010. A guide to understanding the embodied impacts of construction products. Correct as at 2010.
R ICS, 2014. Methodology to calculate embodied carbon. Available at: http://www.rics.org/Global/Methodology_to_calculate_embodied_carbon_1st_
edition_PGguidance_2014.pdf - Anderson, J., 2013. ConstructionLCA's 2017 Guide to Environmental Product Declarations. Available from: https://infogr.am/47216efb-7256-4a5e-acc3-04ce046cbdf8
Anderson, J., 2013. ConstructionLCA's 2017 Guide to Environmental Product Declarations. Available from: https://infogr.am/47216efb-7256-4a5e-acc3-04ce046cbdf8
45 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 46
46 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - The Construction Scope 3 (Embodied) Greenhouse Gas Accounting and Reporting Guidance* written
The Construction Scope 3 (Embodied) Greenhouse Gas Accounting and Reporting Guidance* written
for the Greater London Authority (GLA) contains a series of recommendations which aims to improve
the understanding and consistency of the accounting and reporting of embodied emissions within the
construction sector from cradle-to-grave. This document also provides guidance on how to carry out
calculations to measure the embodied carbon impact of buildings.
Other tools - Elodie (France): http://editions.cstb.fr/Products/Elodie
Elodie (France): http://editions.cstb.fr/Products/Elodie - BRE has an in-house methodology based on BS 15978 on how to calculate the environmental impact of
BRE has an in-house methodology based on BS 15978 on how to calculate the environmental impact of
buildings, including embodied carbon, which embedded in the IMPACT specification is derived from this
methodology (See Section 4.3). - Baubook eco2soft (Austria): http://www.ibo.at/en/ecosoft.htm
Baubook eco2soft (Austria): http://www.ibo.at/en/ecosoft.htm - Athena Impact Estimator (North America): http://www.athenasmi.org/our-software-data/overview/
Athena Impact Estimator (North America): http://www.athenasmi.org/our-software-data/overview/ - Rapiere (UK): http://rapiere.net/ beta version, not commercially available yet.
Rapiere (UK): http://rapiere.net/ beta version, not commercially available yet.
The InnovateUK funded project Implementing Whole Life Carbon in Buildings (IWLCIB) aims to harmonise
the approach to embodied carbon calculations of whole built assets, in accordance with BS 15978 and the
RICS Methodology. This methodology will be available from summer 2017.
4.3 - The following tools are available in other countries based on their respective national data sets (this is not an
The following tools are available in other countries based on their respective national data sets (this is not an
exhaustive list): - It is likely that embodied carbon assessors will have their own bespoke tools. Clients should discuss the use of
It is likely that embodied carbon assessors will have their own bespoke tools. Clients should discuss the use of
these on a case by case status. - Tools
Tools - A number of tools are commercially available to measure the embodied impact of built assets. These enable the
A number of tools are commercially available to measure the embodied impact of built assets. These enable the
user to enter general data about the building design which then generates LCA results. Examples of these tools
include, but are not limited to the following:
5. Whole built asset level assessment methodologies requirements for
embodied carbon - IMPACT compliant tools
IMPACT compliant tools - Whole built asset sustainability assessment schemes are currently one of the main drivers for measuring the
Whole built asset sustainability assessment schemes are currently one of the main drivers for measuring the
embodied carbon of a built asset. - The IMPACT compliant tools are all based on the same methodology and data in line with BS 15978
The IMPACT compliant tools are all based on the same methodology and data in line with BS 15978
requirements. These currently include: - The most commonly used and relevant schemes for the UK are:
The most commonly used and relevant schemes for the UK are:
BREEAM: applicable to UK new (BREEAM UK NC2014) and refurbished non-domestic (BREEAM UK RFO
2015) buildings projects - Home Quality Mark (HQM): applicable to UK new domestic dwellings only
Home Quality Mark (HQM): applicable to UK new domestic dwellings only
LEED v4: applicable to all building types, US standards based but is used on projects in the UK
The IMPACT LCA and the construction data are representative of the UK. More information on IMPACT
compliant tools: http://www.impactwba.com/. - Ska Rating: applicable to non-domestic fit outs, mainly offices and retail units
Ska Rating: applicable to non-domestic fit outs, mainly offices and retail units
CEEQUAL version 5: applicable to civil engineering, infrastructure, landscaping, and public realm projects.
Tally - BREEAM Infrastructure: applicable to new infrastructure assets. This scheme is at pilot stage with projects
BREEAM Infrastructure: applicable to new infrastructure assets. This scheme is at pilot stage with projects
able to register for assessment. - IES-ve IMPACT plug-in (BIM enabled tool)
IES-ve IMPACT plug-in (BIM enabled tool) - eTool;
eTool; - Bionova.
Bionova. - This whole-building assessment tool is designed to work with Revit and has been developed by Kieran
This whole-building assessment tool is designed to work with Revit and has been developed by Kieran
Timberlake, ThinkStep and Autodesk The tool incorporates data from the GaBi database, alongside some EPD,
with data representative of the USA. More information can be found at: http://choosetally.com/
Infrastructure tools - The following selection of tools have been developed for infrastructure assets:
The following selection of tools have been developed for infrastructure assets:
The Rail Carbon Tool is a web-based tool that allows rail carbon footprints to be calculated, assessed,
analysed and reported. Carbon reduction options are evaluated using verified carbon factor data.
https://www.railindustrycarbon.com - The Highways England Carbon Emissions Calculation Tool has been developed to calculate carbon emissions
The Highways England Carbon Emissions Calculation Tool has been developed to calculate carbon emissions
for operational, construction and maintenance activities. - https://www.gov.uk/government/publications/carbon-tool.
https://www.gov.uk/government/publications/carbon-tool. - The Environmental Agencys Carbon Planning Tool provides a mechanism for assessing carbon over the
The Environmental Agencys Carbon Planning Tool provides a mechanism for assessing carbon over the
whole life of built assets. It enables carbon quantification but also implementation of mitigation strategies.
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/571707/LIT_7067.pdf - Transport Scotland has developed a Carbon Management System, based on a series of spreadsheets.
Transport Scotland has developed a Carbon Management System, based on a series of spreadsheets.
http://www.transport.gov.scot/environment/carbon-management-system. - *
* - Greater London Authority (GLA), 2013. Construction Scope 3 (Embodied): Greenhouse Gas Accounting and Reporting Guidance. Available at: https://www.
Greater London Authority (GLA), 2013. Construction Scope 3 (Embodied): Greenhouse Gas Accounting and Reporting Guidance. Available at: https://www.
london.gov.uk/sites/default/files/gla_construction_scope_3_embodied_greenhouse_gas_accounting_and_reporting_guidance_vfinal_1.pdf (See Table 7.2, - pp.27-28)
pp.27-28) -
- Undergoing testing as at February 2017.
Undergoing testing as at February 2017. - This section provides an overview of the schemes requirements in terms of measuring the embodied carbon impact
This section provides an overview of the schemes requirements in terms of measuring the embodied carbon impact
using an LCA approach. It is worth noting that the required assessment methodologies for these various schemes are
specific to each scheme. The scheme assessors should be consulted for further guidance on these aspects.
5.1 - BREEAM
BREEAM - The following detail is based on the BREEAM UK New Construction 2014 scheme. Most BREEAM schemes for
The following detail is based on the BREEAM UK New Construction 2014 scheme. Most BREEAM schemes for
buildings use a similar approach, with the exception of BREEAM In-Use.
The most relevant issues to the embodied carbon impact of buildings are included in the Materials section:
Mat01: Life cycle impacts; - Mat02: Hard landscaping and boundary protection; and
Mat02: Hard landscaping and boundary protection; and
Mat04: Insulation. - Credits for all three are based on the Green Guide ratings and aim to encourage the specification of products
Credits for all three are based on the Green Guide ratings and aim to encourage the specification of products
and building elements with lower environmental impact (see Section 4.1). There are also extra points for
increased use of products with EPDs. - 47
47 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - In addition, Mat01 awards Innovation Credits for the use of whole building LCA software tools. Credits are
In addition, Mat01 awards Innovation Credits for the use of whole building LCA software tools. Credits are
awarded where the design team has: - used an IMPACT compliant or equivalent tool to measure the environmental impact of the asset; and
used an IMPACT compliant or equivalent tool to measure the environmental impact of the asset; and
demonstrated how the use of the tool has benefited the asset in terms of measuring and reducing its
environmental impact. - 48
48 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - The notional baseline and the assessed buildings must:
The notional baseline and the assessed buildings must:
Be of comparable size, function, orientation, and operating energy performance (as defined in EA Prerequisite
Minimum Energy Performance). - Use a service life of at least 60 years to fully account for maintenance and replacement.
Use a service life of at least 60 years to fully account for maintenance and replacement.
Be measured using the same life-cycle assessment software tools and data. Data sets must be compliant
with ISO 14044. - Further information on how to comply with the requirements of Mat01 innovation credits are provided in GN08*.
Further information on how to comply with the requirements of Mat01 innovation credits are provided in GN08*.
BREEAM published its strategy for the future development of its materials section and states that it will be
moving towards a whole building LCA approach. - 5.2
5.2 - The Home Quality Mark (HQM)
The Home Quality Mark (HQM) - HQM is part of the BREEAM family of whole built asset sustainability assessment schemes. It is used to provide
HQM is part of the BREEAM family of whole built asset sustainability assessment schemes. It is used to provide
a customer focused assessment of the impacts and benefits relating to the design, construction and location of
new homes in the UK. It replaces the Governments Code for Sustainable Homes which was withdrawn for new
registrations in 2015. The scheme is currently operating as a beta version and is due to be updated in late 2017.
MR Credit - Building Product Disclosure and OptimizationEnvironmental Product Declarations:
LEED encourages the use of products with critically reviewed LCA and/or EPDs. It also encourages the use of
products that can demonstrate that they have less of an impact than the industry average.
5.4 - the HQM materials reporting tool (foundation route); or
the HQM materials reporting tool (foundation route); or
an IMPACT compliant tool (comprehensive route).
Results (expressed in Ecopoints per occupant) are then compared against the benchmark to estimate the
number of eligible credits. - 5.3
5.3 - LEED v4
LEED v4 - The sections most relevant to the embodied environmental impact of buildings are:
The sections most relevant to the embodied environmental impact of buildings are:
MR Credit: Building Life-Cycle Impact Reduction; and
MR Credit: Building Product Disclosure and OptimizationEnvironmental Product Declarations.
Ska - The sections most relevant to the embodied environmental impact of buildings are:
The sections most relevant to the embodied environmental impact of buildings are:
Embodied environmental impact of homes is mainly addressed in assessment issue 19 Environmental impact
from construction products. This follows a similar approach to that outlined for BREEAM (see above). Credits are
awarded for the use of products with EPDs and for a whole building level environmental impact assessment. The
assessors can either choose: - 49
49 - D19 Green materials specification
D19 Green materials specification - M12 Greener carpets
M12 Greener carpets - M01 Greener blockwork
M01 Greener blockwork - M14 Greener paints
M14 Greener paints - M02 Greener bricks
M02 Greener bricks - M15 Greener polishes & varnishes
M15 Greener polishes & varnishes - M03 Greener screed
M03 Greener screed - M16 Greener wallpaper"
M16 Greener wallpaper" - M04 Greener insulation
M04 Greener insulation - M17 Greener doors
M17 Greener doors - M07 Greener raised floors
M07 Greener raised floors - M18 Greener kitchen fittings
M18 Greener kitchen fittings - M08 Greener partitions
M08 Greener partitions - M19 Greener workstations and tables
M19 Greener workstations and tables - M09 Greener glazed partitions
M09 Greener glazed partitions - M20 Greener desk chairs
M20 Greener desk chairs - M10 Greener ceilings
M10 Greener ceilings - M22 Greener other furniture
M22 Greener other furniture - M11 Greener hard floors
M11 Greener hard floors - M23 Greener blinds and curtains
M23 Greener blinds and curtains - For all of these sections, Ska recommends the use of products with an EPD. Some of the sections (D19, M07,
For all of these sections, Ska recommends the use of products with an EPD. Some of the sections (D19, M07,
M10, M08, M12, M14, M11, M04, M09 and M17) refer to the use of the Green Guide to Specification. Embodied
carbon is covered in the scope of EPDs or Green Guide Specifications but is not assessed on its own within Ska.
Ska does not require an overall embodied carbon measurement for the whole project.
MR Credit -Building Life-Cycle Impact Reduction encourages the reuse or renovation of existing buildings:
5.5 - CEEQUAL v5
CEEQUAL v5 - LEED requires a building level LCA and demonstration of a 10% reduction (minimum) in impact, compared with
LEED requires a building level LCA and demonstration of a 10% reduction (minimum) in impact, compared with
a notional baseline building. The results must be presented against the following impact categories:
CEEQUAL addresses LCA under section 8 Physical Resources, Use and Management.
global warming potential (greenhouse gases), in kg CO2e;
depletion of the stratospheric ozone layer, in kg CFC-11;
The sub-section 8.2 addresses Embodied Impacts at full LCA level and at an embodied carbon level. The greater
the level of detail in the assessment the greater the score. The scheme rewards both LCA studies and the use of
LCA for reducing the impacts of the project.
acidification of land and water sources, in moles H+ or kg SO2;
Sub-sections 8.2.1 and 8.2.2. include:
eutrophication, in kg nitrogen or kg phosphate;
formation of tropospheric ozone, in kg NOx, kg O3 eq, or kg ethene; and
depletion of non-renewable energy resources, in MJ.
The 10% improvement must be demonstrated in at least three of the six impact categories listed above and one
of the three must be global warming potential.
Section 8.2.1 Life Cycle Assessment: - Embodied carbon footprint assessment
Embodied carbon footprint assessment - LCA, but only for key construction materials
LCA, but only for key construction materials - Full LCA covering all life cycle stages
Full LCA covering all life cycle stages - Section 8.2.2 Implementing reductions identified in the LCA
Section 8.2.2 Implementing reductions identified in the LCA
It is worth noting that the LCA methodology used needs to be in line with:
* - www.breeam.org
www.breeam.org -
- http://www.breeam.com/filelibrary/Briefing%20Papers/Strategic-Approach-to-the-Selection-and-Procurement-of-Construction-Materials-and-Products.pdf
http://www.breeam.com/filelibrary/Briefing%20Papers/Strategic-Approach-to-the-Selection-and-Procurement-of-Construction-Materials-and-Products.pdf -
- http://www.bre.co.uk/page.jsp?id=3737
http://www.bre.co.uk/page.jsp?id=3737 - ISO 14040;
ISO 14040; - ISO 14044;
ISO 14044; - EN 15942; and
EN 15942; and - EN 15804.
EN 15804. - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 5.6
5.6 - BREEAM Infrastructure
BREEAM Infrastructure - BREEAM Infrastructure is still at a pilot stage. Currently, LCA is addressed at both project and materials levels.
BREEAM Infrastructure is still at a pilot stage. Currently, LCA is addressed at both project and materials levels.
Several approaches are envisaged, the most comprehensive allowing more credits to be awarded. The
assessment of embodied carbon is rewarded even though a full LCA enables the assessor to achieve more
credits. - 50
50 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - Material quantities and embodied carbon dioxide in structures. The research conducted embodied carbon
Material quantities and embodied carbon dioxide in structures. The research conducted embodied carbon
measurement of 200 buildings in America and Europe*.
Life Cycle Assessment (LCA) and Life Cycle Energy Analysis (LCEA) of Buildings and the Building Sector: A
Review. - 8. Targets
8. Targets - 6. Setting up meaningful comparisons
6. Setting up meaningful comparisons - Meaningful comparisons of assessments are made viable by ensuring each assessment report retains the same:
Meaningful comparisons of assessments are made viable by ensuring each assessment report retains the same:
System boundaries; - Typology and functional unit i.e. assets should be as close to like-for-like as possible e.g. comparing offices to
Typology and functional unit i.e. assets should be as close to like-for-like as possible e.g. comparing offices to
offices and not offices to warehouses; - All requisite scenario assumptions;
All requisite scenario assumptions; - Data sources;
Data sources; - Results reported at a disaggregated level including the same measurement/functional units
Results reported at a disaggregated level including the same measurement/functional units
e.g. kgCO2e per m2*.
Future proofing reporting in this manner is advisable to ensure comparability in a field that is rapidly advancing in
sophistication. - If clients wish to compare two projects, it is possible, although not recommended due to costs, to retrospectively
If clients wish to compare two projects, it is possible, although not recommended due to costs, to retrospectively
adjust a calculation to different data sources/assumptions/quantities/boundaries and make a fair comparison.
Comparisons can also be made to a baseline. Baselines could include:
a comparative baseline from an existing asset within a client portfolio;
comparing an embodied carbon measurement from a baseline design; or
comparing using publicly available benchmarks, such as the Embodied Carbon Database.
When setting any target, it is important to bear in mind the intended or desired outcome. For embodied carbon,
this can be the performance improvement of a specific asset at design stage or a maximum carbon value not to
be exceeded. - The three main approaches when setting targets are:
The three main approaches when setting targets are:
8.1 - Comparative targets
Comparative targets - Comparative targets take the form of a simple embodied carbon reduction compared to a known baseline. An
Comparative targets take the form of a simple embodied carbon reduction compared to a known baseline. An
example could be ensure the building betters the Embodied Carbon Database average for commercial offices of
867 kgCO2e/m2. - 8.2
8.2 - Intensity targets
Intensity targets - Intensity targets are set using metrics based on a function of the assets performance e.g. number of occupants
Intensity targets are set using metrics based on a function of the assets performance e.g. number of occupants
which would be expressed as kgCO2e/FTE.
8.3 - Absolute reduction targets
Absolute reduction targets - Absolute reduction targets are usually expressed as a defined reduction of total embodied carbon. e.g. 25%
Absolute reduction targets are usually expressed as a defined reduction of total embodied carbon. e.g. 25%
reduction compared to the baseline. - Targets can be set by reviewing an existing assessment of a similar built asset to examine the most likely areas
Targets can be set by reviewing an existing assessment of a similar built asset to examine the most likely areas
of reduction. Discussions with the carbon assessor are recommended, prior to undertaking the assessment, to
establish a reduction target. - Whatever baseline is chosen, to be meaningful, the comparison should be made with the criteria identified above.
Whatever baseline is chosen, to be meaningful, the comparison should be made with the criteria identified above.
9. Major wins - 7. Benchmarks
7. Benchmarks - Understanding embodied carbon performance relative to others can assist in making the assessment more
Understanding embodied carbon performance relative to others can assist in making the assessment more
meaningful. Benchmarks for embodied carbon in built assets are currently scarce.
Achieving embodied carbon emissions reductions has the greatest impact if done at the early stages of the
construction project when the design and choices of materials can be influenced.
The two major wins for improvement are: - Examples of available benchmarks include:
Examples of available benchmarks include: - Retention and re-use by retaining and re-using elements of an asset new carbon is not introduced;
Retention and re-use by retaining and re-using elements of an asset new carbon is not introduced;
Embodied Carbon Database , the only free and publicly available benchmark;
RICS Methodology to calculate embodied carbon from May 2014 contains benchmarks for different building
types; - High mass elements and assemblies elements such as the sub-structure or super-structure and assemblies
High mass elements and assemblies elements such as the sub-structure or super-structure and assemblies
such as walls are the aspects of a design that typically have the highest material volumes and masses. By
targeting these high mass items significant gains can be made e.g. reviewing the proposed concrete mixes to
incorporate higher levels of cement replacement or recycled aggregate.
Company benchmarks, which are useful as they can be tailored to a clients needs; and
In addition, academic research studies can also be used for benchmarking. However, they have not been written
for a commercial audience. Such studies include - *
* - It is worth noting that results may refer to differing area metrics e.g. Net Living Area (NLA), Net Internal Area (NIA), Gross Internal Area (GIA), Gross Floor Area
It is worth noting that results may refer to differing area metrics e.g. Net Living Area (NLA), Net Internal Area (NIA), Gross Internal Area (GIA), Gross Floor Area
(GFA). -
- Embodied Carbon Database, 2014. WRAP. Available at: http://ecdb.wrap.org.uk/
Embodied Carbon Database, 2014. WRAP. Available at: http://ecdb.wrap.org.uk/
- R ICS, 2014. Methodology to calculate embodied carbon. Available at http://www.rics.org/uk/knowledge/professional-guidance/guidance-notes/methodologyto-calculate-embodied-carbon-global-guidance-note-1st-edition/
R ICS, 2014. Methodology to calculate embodied carbon. Available at http://www.rics.org/uk/knowledge/professional-guidance/guidance-notes/methodologyto-calculate-embodied-carbon-global-guidance-note-1st-edition/
* - De Wolf et al., 2016. De Wolf, C., Yang, F., Cox, D., Charlson, A., Hattan, A. S. & Ochsendorf, J., 2015. Material Quantities and Embodied Carbon Dioxide
De Wolf et al., 2016. De Wolf, C., Yang, F., Cox, D., Charlson, A., Hattan, A. S. & Ochsendorf, J., 2015. Material Quantities and Embodied Carbon Dioxide
in Structures. Proceedings of the ICE - Engineering Sustainability, pp. 93100. Available from: http://www.icevirtuallibrary.com/content/article/10.1680/
ensu.15.00033 . -
- Cabeza, L. F., Rincn, L., Vilario, V., Prez, G. & Castell, A., 2014. Life Cycle Assessment (LCA) and Life Cycle Energy Analysis (LCEA) of Buildings and
Cabeza, L. F., Rincn, L., Vilario, V., Prez, G. & Castell, A., 2014. Life Cycle Assessment (LCA) and Life Cycle Energy Analysis (LCEA) of Buildings and
the Building Sector: A Review. Renewable and Sustainable Energy Reviews, 29, pp. 394416. Available from: http://linkinghub.elsevier.com/retrieve/pii/
S1364032113005777 -
- Zero Waste Scotland, 2015. Carbon Management: setting targets. Guidance for public sector organisations. Available at: http://www.resourceefficientscotland.
Zero Waste Scotland, 2015. Carbon Management: setting targets. Guidance for public sector organisations. Available at: http://www.resourceefficientscotland.
com/sites/default/files/Setting%20Targets.pdf
- A useful reference document is Cutting Embodied Carbon in Construction Projects, WRAP 2011. See Section 10 for link.
A useful reference document is Cutting Embodied Carbon in Construction Projects, WRAP 2011. See Section 10 for link.
51 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 52
52 - 10. Other key documents
10. Other key documents - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 53
53 - 11. Other Example client briefs
11. Other Example client briefs - Title
Title - Author
Author - Year
Year - What does the publication do?
What does the publication do? - 11.1 British Land, Draft Embodied Carbon Scope
11.1 British Land, Draft Embodied Carbon Scope - Cutting embodied carbon in
Cutting embodied carbon in - construction projects
construction projects - WRAP
WRAP - 2011
2011 - Identifies basic cost-effective actions to reduce the carbon
Identifies basic cost-effective actions to reduce the carbon - impact of the materials used in your construction projects.
impact of the materials used in your construction projects.
Background - A guide to understanding
A guide to understanding - the embodied impacts of
the embodied impacts of - construction products
construction products - Construction
Construction - Products
Products - Association
Association - 2012
2012 - The guide explains:
The guide explains: - how the environmental impacts of construction
how the environmental impacts of construction - products are measured;
products are measured; - what processes and schemes are already established;
what processes and schemes are already established; - what information is generated;
what information is generated; - how this is used and assessed at the building level;
how this is used and assessed at the building level;
and - what effect european regulations and emerging
what effect european regulations and emerging - european standards will have.
european standards will have. - Whole-Life Carbon Footprint
Whole-Life Carbon Footprint - Measurement and Offices
Measurement and Offices - British Council
British Council - of Offices
of Offices - 2012
2012 - Provides a methodology for measuring the whole-life
Provides a methodology for measuring the whole-life - carbon footprint of an office.
carbon footprint of an office. - London 2012 Olympic
London 2012 Olympic - and Paralympic Games The legacy: Sustainable
and Paralympic Games The legacy: Sustainable - Procurement for Construction
Procurement for Construction - Projects
Projects - Defra
Defra - 2013
2013 - Outlines the key principles, as well as processes and tools
Outlines the key principles, as well as processes and tools
used to deliver sustainable development objectives for - London 2012 with a focus on construction. Sustainable
London 2012 with a focus on construction. Sustainable
procurement had an important role to play in relation to
other aspects of the event, which for London 2012 were
largely in the hands of LOCOG which planned, financed
and staged the Games. LOCOG embedded sustainability - in its approach but adopted different tools suited to the
in its approach but adopted different tools suited to the
supply chains involved. - Practical how-to guide:
Practical how-to guide: - measuring embodied carbon
measuring embodied carbon - on a project
on a project - UK-GBC and
UK-GBC and - BRE
BRE - Tackling Embodied Carbon in
Tackling Embodied Carbon in - Buildings
Buildings - UK-GBC and
UK-GBC and - The Crown
The Crown - Estate
Estate - Embodied Carbon & EPDs
Embodied Carbon & EPDs - Jane Anderson,
Jane Anderson, - PE International
PE International - 2014
2014 - 2015
2015 - British Land expects for all Major developments (>50m capex) that embodied carbon emissions be measured
British Land expects for all Major developments (>50m capex) that embodied carbon emissions be measured
and reduced. The aim is to reduce the measured as-built emissions arising from product stage and construction
of landlord elements by 15% based upon the Stage 2 (Concept Design) Embodied Carbon Account. The
structural engineer will champion the embodied carbon review.
BS EN 15978:2011 divides the product stage into three elements Raw material supply, transportation, and
manufacturing process. - This reduction must not be via over provision at concept design stage but demonstrated through clear
This reduction must not be via over provision at concept design stage but demonstrated through clear
assessment and detailing. Current benchmarks for each building type are as follows designs should aim below
or to the lower end of these ranges.
Benchmark Ranges - Compiled January 2015 by Atkins (F&G) using industry information (WRAP, RICS) and existing British Land
Compiled January 2015 by Atkins (F&G) using industry information (WRAP, RICS) and existing British Land
detailed project analysis. - A light-touch guidance note on easy embodied carbon
A light-touch guidance note on easy embodied carbon - reduction strategies on a construction project.
reduction strategies on a construction project. - Addresses the need for new drivers for action on
Addresses the need for new drivers for action on
embodied carbon from within the industry itself, - specifically a clear explanation of the business case for
specifically a clear explanation of the business case for
reducing embodied carbon. It is designed for clients and
developers who want to begin to consider and to reduce
the embodied carbon impacts of their developments. - Provides an overview of the UK and EU approach to
Provides an overview of the UK and EU approach to
embodied carbon and provides a list of useful references.
See 7. Glossary for definitions of commonly used terms and phrases.
kg CO2/m2 - Residential
Residential - Cinema/Leisure
Cinema/Leisure - Office
Office - Retail
Retail - Sub-structure
Sub-structure - 120-170
120-170 - 100-130
100-130 - 190-230
190-230 - 230-270
230-270 - Super structure
Super structure - 180-200
180-200 - 240-260
240-260 - 430-460
430-460 - 240-260
240-260 - Ex. Cladding
Ex. Cladding - 180-200
180-200 - 180-200
180-200 - 110-150
110-150 - 170-190
170-190 - Landlord M+E
Landlord M+E - 70-90
70-90 - 50-70
50-70 - 70-90
70-90 - 70-90
70-90 - Requirements for each RIBA stage
Requirements for each RIBA stage - Stage 1 Briefing
Stage 1 Briefing - Include a requirement in the project brief and relevant appointment documents to undertake an analysis of
Include a requirement in the project brief and relevant appointment documents to undertake an analysis of
embodied carbon. A suitable benchmark will be established based on building type and the best practice
benchmarks, against which an analysis will be undertaken that will inform design decisions to achieve the
embodied carbon reduction target. - Stage 2 Concept to Planning
Stage 2 Concept to Planning - During early Stage 2 undertake a workshop with relevant design team members such as the cost consultant,
During early Stage 2 undertake a workshop with relevant design team members such as the cost consultant,
architect, structural engineer and MEP consultant to confirm roles and responsibilities, and:
Establish the appropriate embodied energy benchmark for the building types and based on the above
British Land specific benchmarks, and as informed by current industry best practice at the time of review
confirm the embodied carbon reduction target - agree the sources of embodied data to be utilised
agree the sources of embodied data to be utilised
discuss opportunities to reduce embodied carbon through the proposed structure and materials selection
(at this stage regardless of cost implications)
identify potential design challenges or site constraints - Report on the outline proposals for the project and prepare an embodied carbon account for the
Report on the outline proposals for the project and prepare an embodied carbon account for the
development using available industry estimates and initial design concepts. Include the data alongside the
cost plan to provide a reasonable level of subdivision.
EMBODIED CARBON: SUPPORTING GUIDANCE - Embodied carbon factors are available from existing databases including the Inventory of Carbon and Energy
Embodied carbon factors are available from existing databases including the Inventory of Carbon and Energy
(ICE), obtained from manufacturers product datasheets, or using Environmental Products Declarations (EPDs).
At a minimum, the embodied carbon account shall provide a breakdown as follows:
Substructure - Foundations
Foundations - Basement retaining walls
Basement retaining walls - Ground floor construction
Ground floor construction - Superstructure
Superstructure - Frame
Frame - External walls, cladding & exterior works
External walls, cladding & exterior works - Windows and external doors
Windows and external doors - Roof
Roof - Upper floors
Upper floors - Stairs and ramps
Stairs and ramps - Services
Services - 54
54 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - RIBA Stage 3 Developed Design
RIBA Stage 3 Developed Design - The design team shall review the Carbon Mitigation Plan and confirm all Stage 2 recommendations have
The design team shall review the Carbon Mitigation Plan and confirm all Stage 2 recommendations have
been considered and fully explored. Carry forward outstanding initiatives into the developed design.
Comment on design documents prepared by the other consultants in respect of the embodied carbon
implications of alternative design and construction approaches. Comment in respect of the design of each
element in relation to the allowances therefore contained in the Embodied Carbon Account or any drafts
there. - Undertake a focussed workshop to review the developed design against the embodied carbon account, the
Undertake a focussed workshop to review the developed design against the embodied carbon account, the
reduction target, and the recommendations set out in the Carbon Mitigation Plan and identify any further
opportunities to reduce embodied energy - embed these in the developed design.
Mid to late Stage 3 the embodied carbon account shall be revised for the development based on the
developed design prepared by the all consultants and in a form to be approved by the client.
Agree this account with the client. - The cost consultant is to assist the architect, the structural engineer, and MEP consultant to agree the
The cost consultant is to assist the architect, the structural engineer, and MEP consultant to agree the
embodied carbon account for the development with the client.
Align Stage 3 drawings, specifications and building models to accord with the design initiatives to achieve the
target. - Compare this account with the British Land embodied carbon benchmark(s) that have been set for the
Compare this account with the British Land embodied carbon benchmark(s) that have been set for the
development project and submit the embodied carbon account to the client for approval.
Undertake a follow-up workshop and review implications of the embodied carbon information with the
client and the design team and identify opportunities and set recommendations. The design team will use
the information to inform structural solutions for the building. Identify specific areas of design where carbon
reduction is to be targeted to achieve the minimum target and prepare a Carbon Mitigation Plan that lists
the opportunities to be embedded into the design as Stage 2 progresses.
Opportunities identified at Stage 2 that have not been possible to embed into the developed design
should be clearly explained in the Stage 3 report. The Carbon Mitigation Plan should form a part of, or be
summarised and appended to, the Stage 3 for client sign off.
RIBA Stage 4 Technical Design - Monitor technical design to ensure is accords with the initiatives in the developed design and the
Monitor technical design to ensure is accords with the initiatives in the developed design and the
opportunities set out in the Carbon Mitigation Plan required to achieve the embodied carbon target.
Provide embodied carbon advice and information to the other consultants for the purpose of establishing a
concept design. - By the end of Stage 2, the opportunities to achieve the embodied carbon target should be clearly
By the end of Stage 2, the opportunities to achieve the embodied carbon target should be clearly
understood, and any constraints explained in the Carbon Mitigation Plan.
The cost consultants and structural engineer shall prepare a list of checks for review during Stage 5, to
facilitate the achievement of the carbon reduction target. These will be listed in the Carbon Mitigation Plan,
which will be appended to the tender documentation.
Align Stage 2 drawings, specifications and building models to accord with the initiatives to achieve the target.
Prepare a list of recommendations for review in future stages of design to manage and reduce embodied
carbon emissions associated with the development and incorporate into the Carbon Mitigation Plan. The
Carbon Mitigation Plan should form a part of, or be summarised and appended to, the Stage 2 for client sign
off. - If necessary, prepare a report on information to be requested and procedures to be adopted regarding
If necessary, prepare a report on information to be requested and procedures to be adopted regarding
embodied carbon in inviting tenders for the construction of the development and the contract conditions to
be used. - Input into the tender documentation to ensure all design initiatives required to meet the embodied carbon
Input into the tender documentation to ensure all design initiatives required to meet the embodied carbon
reduction target are part of the employers requirements, and have been allowed for within the contractors
proposals. - General comments:
General comments: - RIBA Stage 5 Construction
RIBA Stage 5 Construction - The consultant will declare any data sources used.
The consultant will declare any data sources used.
The methodology for calculation will be based on the RICS Methodology to Calculate Embodied Carbon
(1st edition). - The checklist from the Carbon Mitigation Plan will be reviewed by the project team (cost consultant, architect
The checklist from the Carbon Mitigation Plan will be reviewed by the project team (cost consultant, architect
and structural engineer) and the contractors to facilitate the achievement of the parameters established in the
approved Embodied Carbon Account from Stage 3. - Any models produced will be given to BL in a working form.
Any models produced will be given to BL in a working form.
British Land may choose to publish these results in its annual report or elsewhere.
The Main Contractor shall revise the embodied carbon account for the development based on the as built
materials procured, using where available, manufacturers product datasheets or Environmental Products
Declarations (EPDs) (where these are not available use the averages from the database(s)).
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EMBODIED CARBON: SUPPORTING GUIDANCE - 57
57 - 11.2 Derwent London, Embodied Carbon Brief
11.2 Derwent London, Embodied Carbon Brief - Available from: https://www.derwentlondon.com/uploads/downloads/Derwent_London_Embodied_Carbon_
Available from: https://www.derwentlondon.com/uploads/downloads/Derwent_London_Embodied_Carbon_ - Assessment.pdf
Assessment.pdf - Context
Context - As part of our ongoing sustainability programme we are continuing to map and
As part of our ongoing sustainability programme we are continuing to map and
understand our carbon footprint in greater detail. As part of this process we are
looking to explore further our Scope 3 emissions by mapping and investigating the
embodied carbon footprints of our new developments and major refurbishments,
to help us understand its significance and where there are opportunities to reduce
our footprint. - From the initial studies undertaken it has been demonstrated that our preferred
From the initial studies undertaken it has been demonstrated that our preferred
approach to development i.e. re-energising older buildings to add value and unlock
potential, achieves lower embodied carbon profiles when compared to more
standard/generic approaches. However, it is important for us to understand exactly
where the true reduction opportunities lie and how we can take advantage of them.
To enable us to measure embodied carbon across our project portfolio effectively
and consistently we have developed this brief which is designed to guide carbon
consultants as to the extent of the assessment and outputs required.
Summary - This brief sets out the base requirements and outputs for an embodied carbon
This brief sets out the base requirements and outputs for an embodied carbon
assessment instructed by Derwent London. It is envisaged that any assessment
commissioned will be done so at the earliest opportunity, with a target start point
of RIBA stage C (Stage 2 in the new plan of work) to capture the design concept,
moreover to run through to Stage D (Stage 3) to capture the design development
stage. Where required it may be that this assessment window will be extended
beyond these stages to capture other aspects, but this will be dealt with on an
individual basis. - During the delivery phase of the project the main contractor will be required
During the delivery phase of the project the main contractor will be required
separately to map the footprint during construction to allow for comparison at project
completion. - It is recognised that each consultant practice will have their own format/house style
It is recognised that each consultant practice will have their own format/house style
for presenting the results for their assessments; this brief is not intended to direct
this, rather set out some of the basic parameters Derwent London requires.
Requirements - Framework
Framework - Up until very recently there have no specific made-for-purpose embodied carbon
Up until very recently there have no specific made-for-purpose embodied carbon
assessment frameworks focused specifically on buildings, however this has
changed with the introduction of BS EN 15978:2011, which is becoming the pillar
standard in terms of life cycle assessment in buildings.
It is necessary that all assessments undertaken must have their methods aligned
to/conform with BS EN 15978:2011 Sustainability of construction works
Assessment of environmental performance of buildings Calculation method.
With regards to datasets it is recognised that there are no formally endorsed
databases/sets referenced by the above standard or others, outwith Environmental
Product Declarations (EPDs), however it is recognised that there a number of wellused industry benchmarks and sources, which include:
The Bath ICE Database; - Proprietary databases and software packages such as SimaPro; and
Proprietary databases and software packages such as SimaPro; and
Environmental Product Declarations (EPDs) - In addition to these it is understood that many practices will have data obtained
In addition to these it is understood that many practices will have data obtained
from other sources such as first principle studies based on research undertaken
elsewhere. As a result it is to be made clear in the method description all the data
sources used to complete the assessment both primary and secondary and
their provenance and treatment i.e. how they have been used and the standards
they conform to e.g. PAS 2050 or ISO 14040. Moreover, how issues such as
recycled material allocation, timber sequestration, cut-offs and end-of-life have
been dealt with. - Assessment boundaries & metrics
Assessment boundaries & metrics - The boundary condition to be used is: Cradle-to-Completed Construction.
The boundary condition to be used is: Cradle-to-Completed Construction.
The primary reporting unit is to be: tCO2e
As a minimum the assessment is to present the following headline metrics:
Total tCO2e i.e. the total embodied carbon footprint;
Total tCO2e per m2 (based on Gross Internal floor Area [GIA]);
Total tCO2e per carbon source, split by: materials, transport, site activities/
impacts; and waste also to be expressed as a percentage of the total footprint
02 - EMBODIED CARBON: SUPPORTING GUIDANCE
EMBODIED CARBON: SUPPORTING GUIDANCE - 58
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EMBODIED CARBON: SUPPORTING GUIDANCE - 59
59 - 11.3 HS2, EIA Scope and Methodology
11.3 HS2, EIA Scope and Methodology - It is recognised that there may be multiple buildings or use types under
It is recognised that there may be multiple buildings or use types under
investigation in an assessment. Where this is the case the above metrics are
to be presented for each distinct building/use type.
HS2's publicly available Environmental Impact Assessment for Phase 2A of the works.
Results presentation & benchmark comparison - The assessment as a minimum should present the outcomes from the assessment
The assessment as a minimum should present the outcomes from the assessment
graphically in the following ways: - Total tCO2e per building element i.e. superstructure, substructure etc and each
Total tCO2e per building element i.e. superstructure, substructure etc and each
expressed as a percentage of the total footprint; and
Total tCO2e per major building component i.e. walls, floors etc and each
expressed as a percentage of the total footprint - Commentary should also be provided explaining the results, significant findings,
Commentary should also be provided explaining the results, significant findings,
relationships etc. - The assessment should also provide a benchmark comparison building/s in order
The assessment should also provide a benchmark comparison building/s in order
to compare the results effectively. Any benchmarks used should be as directly
comparable as possible, however it is recognised that this may not always be
possible. Therefore, it is acceptable to use a generic benchmark, however full
explanation is to be given as to the make-up of the benchmark and its limitations.
Conclusions & reduction opportunities - Within the conclusion section, the top five reduction opportunities are to be
Within the conclusion section, the top five reduction opportunities are to be
presented together with their reduction potential against the total footprint.
These opportunities should be practicable and realistic and in line with the
project objectives. - Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/506111/HS2_
Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/506111/HS2_ - Phase_2a_EIA_Scope_and_Methodology_Report_Final_for_Comms_08-03-2016_WEB_1400.pdf
Phase_2a_EIA_Scope_and_Methodology_Report_Final_for_Comms_08-03-2016_WEB_1400.pdf - Acknowledgements
Acknowledgements - Project Team
Project Team - Technical Review
Technical Review - Matt Barron, Walsh
Matt Barron, Walsh - John Davies, Derwent London
John Davies, Derwent London - Nick Drake, Carillion
Nick Drake, Carillion - Mark Edwards, UK-GBC
Mark Edwards, UK-GBC - Natalia Ford (Project Lead), UK-GBC
Natalia Ford (Project Lead), UK-GBC - Shamir Ghumra, BRE
Shamir Ghumra, BRE - Sarah Hodson, Carillion
Sarah Hodson, Carillion - Flavie Lowres, BRE (funded by the BRE Trust)
Flavie Lowres, BRE (funded by the BRE Trust)
Elodie Mac, BRE - Peyrouz Modarres, Walsh
Peyrouz Modarres, Walsh - Erica Russell, Carillion
Erica Russell, Carillion - Aidan Wingfield, Walsh
Aidan Wingfield, Walsh - Workshop Attendees
Workshop Attendees - Where opportunities identified have operational energy implications or require
Where opportunities identified have operational energy implications or require
additional analysis using operational energy data to qualify them, these are to be
brought to the attention of the Derwent London Development Manager and Head
of Sustainability such that an appropriate decision can be made, as to whether
these are to be pursued. - WRAP embodied carbon database
WRAP embodied carbon database - The results from the assessment are to be incorporated into the WRAP Embodied
The results from the assessment are to be incorporated into the WRAP Embodied
Carbon database of buildings using the prerequisite template which can be found
at: http://www.wrap.org.uk/content/embodied-carbon-database - Derwent London plc / June 2016
Derwent London plc / June 2016 - 03
03 - Katharine Agapitos, HS2
Katharine Agapitos, HS2 - Meike Borchers, WSP | Parsons Brinckerhoff
Meike Borchers, WSP | Parsons Brinckerhoff - Louisa Bowles, Hawkins\Brown
Louisa Bowles, Hawkins\Brown - Alan Bunting, British Land
Alan Bunting, British Land - Maria Cachafeiro, Multiplex
Maria Cachafeiro, Multiplex - Louise Clarke, Berkeley Homes
Louise Clarke, Berkeley Homes - Hafiz Elhag, Mineral Products Association
Hafiz Elhag, Mineral Products Association - Chris Horton, Carillion
Chris Horton, Carillion - Jennifer Juritz, David Morley Architects
Jennifer Juritz, David Morley Architects - Tom King, Bouygues UK
Tom King, Bouygues UK - Alexia Laird, Canary Wharf Group
Alexia Laird, Canary Wharf Group - Alistair Maxwell, Heathrow Airport
Alistair Maxwell, Heathrow Airport - Athina Papakosta, Sturgis Carbon Profiling
Athina Papakosta, Sturgis Carbon Profiling - Libbe Ragget, Capco
Libbe Ragget, Capco - David Semple, Grosvenor Britain and Ireland
David Semple, Grosvenor Britain and Ireland - Matt Smith, Lendlease
Matt Smith, Lendlease - Amanda Stevenson, Capco
Amanda Stevenson, Capco - Simon Sturgis, Sturgis Carbon Profiling
Simon Sturgis, Sturgis Carbon Profiling - Chris Twinn, Twinn Sustainability Innovation
Chris Twinn, Twinn Sustainability Innovation - Jane Wakiwaka, The Crown Estate
Jane Wakiwaka, The Crown Estate - Jack White, Latimer Homes
Jack White, Latimer Homes - Zoe Young, M&S
Zoe Young, M&S - Eleanor Clarke, WSP | Parsons Brinckerhoff
Eleanor Clarke, WSP | Parsons Brinckerhoff - Jannik Giesekam, University of Leeds
Jannik Giesekam, University of Leeds - With thanks to:
With thanks to: - Sarah Cary, British Land
Sarah Cary, British Land - Ed Dixon, Land Securities
Ed Dixon, Land Securities - walking line
walking line - a line on the plan of a curving staircase on which all treads are of a uniform width and that is considered to be the ordinary path taken by persons on the stair.
a line on the plan of a curving staircase on which all treads are of a uniform width and that is considered to be the ordinary path taken by persons on the stair.
QUIZZES - QUIZ YOURSELF ON THE 12 TYPES OF VERB TENSES!
QUIZ YOURSELF ON THE 12 TYPES OF VERB TENSES!
Loosen up your grammar muscles because its time to test your knowledge on verb tenses!
Question 1 of 6 - The verb tenses can be split into which 3 primary categories?
The verb tenses can be split into which 3 primary categories?
How to use walking line in a sentence - Domestically, the prime minister maintains the dubious line that he is the only man who can keep the still-fragile peace.
Domestically, the prime minister maintains the dubious line that he is the only man who can keep the still-fragile peace.
He wore white gloves, a dignified long black coat, and matching pants and vest, and he carried a dark walking stick.
They became so brown and shriveled that they looked like walking beef jerky with New York accents.
Last week I turned 40, a bittersweet occasion because I crossed the line to living longer without my mother than with her.
Completed in 1953 and composed with standard line breaks and punctuation, the book was completely ignored upon submission.
Some weeks after, the creditor chanced to be in Boston, and in walking up Tremont street, encountered his enterprising friend.
In this position, the line of cavalry formed the chord of the arc described by the river, and occupied by us.
All changes are to be Rang either by walking them (as the term is) or else Whole-pulls, or Half-pulls.
Our talk ranged from the Panhandle to the Canada line, while our horses jogged steadily southward.
I have drawn a Line between the figures at the extream changes, that next below the Line is the extream.
Find a Showroom - Pella Windows & Doors of Scarborough400 Expedition Drive Suite BScarborough, ME 04074Showroom Details
Pella Windows & Doors of Scarborough400 Expedition Drive Suite BScarborough, ME 04074Showroom Details
Other Showrooms Near You - Not seeing a showroom near you? Don't worry, we'll come to you!
Not seeing a showroom near you? Don't worry, we'll come to you!
What Are Egress Windows? - A finished basement can be one of the simplest ways to add extra space to your home. It can be a good area for bedrooms, a family room or a playroom.
A finished basement can be one of the simplest ways to add extra space to your home. It can be a good area for bedrooms, a family room or a playroom.
As you get ready for your basement remodeling project, be aware that you may need to put in larger windows. Egress windows are large openings that offer a secondary exit in case of an emergency. They can also add more natural light and make your basement feel more inviting.
Basement bedrooms and living spaces are required to have egress windows. Living rooms can be offices, TV rooms or workshops. This mandate also involves unfinished basements. Egress windows are important and serve as peace of mind in case a house fire were to happen.
Basement Windows in Older Homes May Be Too Small
Basements in older homes were not created to be sleeping or living areas. This is especially true for homes constructed before World War II.
Homeowners at that time used their basements for utility space, laundry and storage. Depending on its age, your home may have been built before up-to-date egress window requirements or it may have windows with a smaller opening.
If you live in an older home, theres a likelihood it has narrow windows in the basement. Also known as hopper windows, these above-ground windows open inward to provide fresh air. But these windows are smalltoo small for an adult or fully-equipped first responder to enter through so you will not be able to have a bedroom or living space in your basement without an update that matches the current code in your area.
Requirements for Egress Windows in Basements - Building codes mandate the size of basement windows. This allows for a quick exit in an emergency. According to the International Residential Code, basement windows must have:
Building codes mandate the size of basement windows. This allows for a quick exit in an emergency. According to the International Residential Code, basement windows must have:
An opening width of at least 20 inches.
An opening height of at least 24 inches.
A net clear opening of at least 821 square inchesor 5.7 square feet.
A sill no more than 44 inches off the floor.
How to Measure Your Basement Windows - Not sure if your existing basement windows meet todays requirements? All you need is a tape measure.
Not sure if your existing basement windows meet todays requirements? All you need is a tape measure.
Open the window as wide as possible. - Measure the width and height of the opening.
Measure the width and height of the opening.
Multiply the width by the height. - Is your measurement equivalent to the required 821 square inchesor 5.7 square feet? If not, you will need to have larger windows installed to meet requirements.
Is your measurement equivalent to the required 821 square inchesor 5.7 square feet? If not, you will need to have larger windows installed to meet requirements.
What if My Basement Windows are Below Ground Level?
If your basement windows are beneath ground level, you will need to have a well dug underneath the window frame. This well must be at least 36 inches wide and 36 inches long. If the well is more than 44 inches deep, it will need a fixed ladder or steps.
Using timber or concrete blocks in the well makes it uncomplicated to add steps. Plus, you can incorporate a couple of small landscaping features, like crushed rock or potted plants.
It's acceptable for basement windows to be under a deck or porch, but there needs to be enough clearance for an average-sized adult to exit. There should be at least 36 inches between the top of the window well and the bottom of the deck or porch joists.
Other Requirements for Egress Windows in Basements - Because basement windows are a way out, they must open from the inside. Any screens, grilles or bars need to be removed from the inside without keys or tools.
Because basement windows are a way out, they must open from the inside. Any screens, grilles or bars need to be removed from the inside without keys or tools.
Its also vital that basement windows can completely open. The window sash shouldnt obstruct the opening. This allows your family to quickly exitor first responders to quickly enter.
Local requirements for basement windows may vary. Check with your local building officials to learn more about area guidelines in your neighborhood.
Choosing Basement Egress Windows - There are several styles of windows that work well for basements and meet building code requirements.
There are several styles of windows that work well for basements and meet building code requirements.
Casement Windows - Casement windows are a good option if you dont have much wall space. These windows operate like a door, swinging free to provide a wide opening.
Casement windows are a good option if you dont have much wall space. These windows operate like a door, swinging free to provide a wide opening.
Casement windows open by rotating a handle. Pella casement windows feature a crank that folds away. That way, the crank won't get in the way of window treatments. This window must have at least 8 square feet of net opening.
Sliding Windows - Sliding windows are great for adding more light to spacious basements. These windows have to be wider and taller because the opening is only half as wide as the window. This is due to the sash, which slides horizontally.
Sliding windows are great for adding more light to spacious basements. These windows have to be wider and taller because the opening is only half as wide as the window. This is due to the sash, which slides horizontally.
Sliding windows open by shifting the sash from left to right. Some Pella models include extra-durable tandem nylon rollers. These rollers give even more effortless operation. This window must have at least 16 square feet of net opening.
Talk with the Professionals at Pella - Basement escape windows are a must-have for downstairs living spaces. They can be a lifesaving tool in an emergency. Meet with your local Pella professionals to find the right solution when you're redoing your basement.
Basement escape windows are a must-have for downstairs living spaces. They can be a lifesaving tool in an emergency. Meet with your local Pella professionals to find the right solution when you're redoing your basement.
Window frame - Figure 1. A cross section of a vinyl window frame with two panes of glass.[1]
Figure 1. A cross section of a vinyl window frame with two panes of glass.[1]
The window frame is the portion of the window that holds the glazing and sits between the glazing and the wall of the building when installed. The frame can be fairly simple in a non-operable window to very complex with numerous moving parts in an operable, multi-pane window. Overall, the main function of a frame is to hold the panes of the window in placewith the aid of spacersand hold the window into the wall of a building.
Taking into account the frame as well as the glazing when choosing a window is vitally important in ensuring that the energy efficiency of the window is suitable. Looking at the U-values of windows along with their frames can provide a more complete idea of how well a window will insulate.[2] In addition, the choice of the right window frame, especially a modern window frame, can cut air infiltration in a home down to nearly zero by covering cracks and creating a good seal. This can cut up to 40% off of heating and cooling bills.[3]
Window frames can be made out of a wide variety of materials, and can be made solely out of one material or a composite of numerous materials. The most common frame types are wood, vinyl, aluminum, and more recently fiberglass frames. Composite frames include vinyl or aluminum clad wood products, wood clad vinyl products and other combinations to meet a variety of demands.[4]
Building Materials - Modern window frames can be made from a variety of materials, each with their own benefits and drawbacks. The four main materials used in building window frames are:[5]
Modern window frames can be made from a variety of materials, each with their own benefits and drawbacks. The four main materials used in building window frames are:[5]
Wood: Wood frames have been used extensively in window frame construction for their warm look, insulating properties, and the ability to paint them to refresh how the frames look. Wood frames are the most common choice for frames as they can be painted a solid colour or stained and sealed. However, compared to vinyl and fiberglass frames, wood frames require more maintenance including regular sealing, staining, and painting. Although affordable, they may not provide the highest levels of insulation and are prone to cracking, in turn letting untreated air and water into the home.
Fiberglass: Fiberglass window frames are beneficial as they are extremely strong, low maintenance, look traditional, and are paintable window frame options. These frames are composed of glass fibers and resin, and are very well suited for environments with drastically changing temperatures as the frames are resistant to expansion and contraction due to weather changes. These frames are desirable as they replicate the look and feel of wood without swelling, rotting, or warping and they are more energy efficient than wood frames. However, fiberglass frames are significantly more expensive than wooden frames.
Vinyl: Vinyl frames are a newer type of frame, made primarily of polyvinyl chloride or PVC. These frames are durable, extremely energy efficient, not susceptible to corrosion, and are essentially maintenance-free. Different vinyl composites that contain different additives can be used to give the frame different qualities. The addition of titanium dioxide makes the vinyl frames more heat resistant, for example. Vinyl frames are the least expensive of all material options, but their lack of maintenance and good insulating qualities also make vinyl frames an appealing option.
Aluminum: Aluminum window frames are valued for their slim profile but durability, along with their low maintenance and strength. Due to their lightweight construction and strength, aluminum window frames are able to be configured in a variety of ways. This makes them beneficial for multi-panel systems or large windows. However, aluminum frames are not recommended in wet areas or areas that have high levels of salty water and air due to their corrosion. In addition, the welded joints can weaken over time, resulting in cracking and breaking. However, compared to vinyl, fiberglass, and wood frames aluminum frames are the least energy efficient as they conduct heat well. To reduce this, some companies have equipped aluminum frames with thermal breaks that separate the interior and exterior surfaces of the frame to reduce heat transfer.
"Clad" frames are also a type of composite frame that are available. These frames consist of a vinyl or aluminum exterior and a wooden interior. These frames are more durable and require less maintenance, but are significantly more expensive than other frames.[6]
Authors and Editors - Bethel Afework, Jordan Hanania, Kailyn Stenhouse, Jason Donev Last updated: June 4, 2018 Get Citation
Bethel Afework, Jordan Hanania, Kailyn Stenhouse, Jason Donev Last updated: June 4, 2018 Get Citation
Technical Notes 31 - Brick Masonry Arches - January 1995
January 1995 - Abstract: The masonry arch is one of the oldest structural elements. Brick masonry arches have been used for
Abstract: The masonry arch is one of the oldest structural elements. Brick masonry arches have been used for
hundreds of years. This Technical Notes is an introduction to brick masonry arches. Many of the different types of
brick masonry arches are discussed and a glossary of arch terms is provided. Material selection, proper
construction methods, detailing and arch construction recommendations are discussed to ensure proper structural
support, durability and weather resistance of the brick masonry arch.
Key Words: arch, brick, reinforced, unreinforced.
INTRODUCTION - In the latter part of the 19th century, an arch was discovered in the ruins of Babylonia. Archeologists estimate that
In the latter part of the 19th century, an arch was discovered in the ruins of Babylonia. Archeologists estimate that
the arch was constructed about the year 1400 B.C. Built of well-baked, cigar-shaped brick and laid with clay
mortar, this arch is probably the oldest known to man. The Chinese, Egyptians and others also made use of the
arch before the Christian era. Later, more elaborate arches, vaults and domes with complicated forms and
intersections were constructed by Roman builders during the Middle Ages.
The brick arch is the consummate example of form following function. Its aesthetic appeal lies in the variety of
forms which can be used to express unity, balance, proportion, scale and character. Its structural advantage
results from the fact that under uniform load, the invoiced stresses are principally compressive. Because brick
masonry has greater resistance to compression than tension, the masonry arch is frequently the most efficient
structural element to span openings. - This Technical Notes addresses the detailing and construction of brick masonry arches. The common types of
This Technical Notes addresses the detailing and construction of brick masonry arches. The common types of
brick masonry arches are presented, along with proper arch terminology. Methods of selecting the type and
configuration of brick masonry arches most appropriate for the application are discussed. Proper material
selection and construction methods are recommended. Other Technical Notes in this series discuss the structural
design of brick masonry arches and lintels. - ARCH TYPES AND TERMINOLOGY
ARCH TYPES AND TERMINOLOGY - Many arch forms have been developed during the centuries of use, ranging from the jack arch through the
Many arch forms have been developed during the centuries of use, ranging from the jack arch through the
circular, elliptical and parabolic to the Gothic arch. Figure 1 depicts examples of structural masonry arches used
in contemporary construction. An arch is normally classified by the curve of its intrados and by its function, shape
or architectural style. Figure 2 illustrates some of the many different brick masonry arch types. Jack, segmental,
semicircular and multicentered arches are the most common types used for building arches. For very long spans
and for bridges, semicircular arches are often used because of their structural efficiency.
Structural Brick Arches - FIG. 1
FIG. 1 - Arch Types: Jack
Arch Types: Jack - FIG. 2a
FIG. 2a - Arch Types: Segmental
Arch Types: Segmental - FIG. 2b
FIG. 2b - Arch Types: Semicircular
Arch Types: Semicircular - FIG. 2c
FIG. 2c - Arch Types: Bullseye
Arch Types: Bullseye - FIG. 2d
FIG. 2d - Arch Types: Horseshoe
Arch Types: Horseshoe - FIG. 2e
FIG. 2e - Arch Types: Multicentered
Arch Types: Multicentered - FIG. 2f
FIG. 2f - Arch Types: Venetian
Arch Types: Venetian - FIG. 2g
FIG. 2g - Arch Types: Tudor
Arch Types: Tudor - FIG. 2h
FIG. 2h - Arch Types: Triangular
Arch Types: Triangular - FIG. 2i
FIG. 2i - Arch Types: Gothic
Arch Types: Gothic - FIG. 2j
FIG. 2j - Mainly due to their variety of components and elements, arches have developed their own set of terminology.
Mainly due to their variety of components and elements, arches have developed their own set of terminology.
Following is a glossary of arch terminology. Figure 3 illustrates many of the terms defined in this glossary.
Technical Notes in this series will use this terminology.
Abutment: The masonry or combination of masonry and other structural members which support one end of the
arch at the skewback. - Arch: A form of construction in which masonry units span an opening by transferring vertical loads laterally to
Arch: A form of construction in which masonry units span an opening by transferring vertical loads laterally to
adjacent voussoirs and, thus, to the abutments. Some common arch types are as follows:
Blind -An arch whose opening is filled with masonry.
Bullseye -An arch whose intrados is a full circle. Also known as a Circular arch.
Elliptical -An arch with two centers and continually changing radii.
Fixed -An arch whose skewback is fixed in position and inclination. Masonry arches are fixed arches by
nature of their construction. - Gauged -An arch formed with tapered voussoirs and thin mortar joints.
Gauged -An arch formed with tapered voussoirs and thin mortar joints.
Gothic -An arch with relatively large rise-to-span ratio, whose sides consist of arcs of circles, the centers
of which are at the level of the spring line. Also referred to as a Drop, Equilateral or Lancet arch,
depending upon whether the spacings of the centers are respectively less than, equal to or more than the
clear span. - Horseshoe -An arch whose intrados is greater than a semicircle and less than a full circle. Also known as
Horseshoe -An arch whose intrados is greater than a semicircle and less than a full circle. Also known as
an Arabic or Moorish arch. - Jack -A flat arch with zero or little rise.
Jack -A flat arch with zero or little rise.
Multicentered -An arch whose curve consists of several arcs of circles which are normally tangent at their
intersections. - Relieving -An arch built over a lintel, jack arch or smaller arch to divert loads, thus relieving the lower arch
Relieving -An arch built over a lintel, jack arch or smaller arch to divert loads, thus relieving the lower arch
or lintel from excessive loading. Also known as a Discharging or Safety arch.
Segmental -An arch whose intrados is circular but less than a semicircle.
Semicircular -An arch whose intrados is a semicircle (half circle).
Slanted -A flat arch which is constructed with a keystone whose sides are sloped at the same angle as
the skewback and uniform width brick and mortar joints.
Triangular -An arch formed by two straight, inclined sides.
Tudor -A pointed, four-centered arch of medium rise-to-span ratio whose four centers are all beneath the
extrados of the arch. - Venetian -An arch formed by a combination of jack arch at the ends and semicircular arch at the middle.
Venetian -An arch formed by a combination of jack arch at the ends and semicircular arch at the middle.
Also known as a Queen Anne arch. - Camber: The relatively small rise of a jack arch.
Camber: The relatively small rise of a jack arch.
Centering: Temporary shoring used to support an arch until the arch becomes self-supporting.
Crown: The apex of the arch's extrados. In symmetrical arches, the crown is at the midspan.
Depth: The dimension of the arch at the skewback which is perpendicular to the arch axis, except that the depth
of a jack arch is taken to be the vertical dimension of the arch at the springing.
Extrados: The curve which bounds the upper edge of the arch.
Intrados: The curve which bounds the lower edge of the arch. The distinction between soffit and intrados is that
the intrados is a line, while the soffit is a surface.
Keystone: The voussoir located at the crown of the arch. Also called the key.
Label Course: A ring of projecting brickwork that forms the extrados of the arch.
Rise: The maximum height of the arch soffit above the level of its spring line.
Skewback: The surface on which the arch joins the supporting abutment.
Skewback Angle: The angle made by the skewback from horizontal.
Soffit: The surface of an arch or vault at the intrados.
Span: The horizontal clear dimension between abutments.
Spandrel: The masonry contained between a horizontal line drawn through the crown and a vertical line drawn
through the upper most point of the skewback.
Springing: The point where the skewback intersects the intrados.
Springer: The first voussoir from a skewback.
Spring Line: A horizontal line which intersects the springing.
Voussoir: One masonry unit of an arch.
Arch Terms - FIG. 3
FIG. 3 - STRUCTURAL FUNCTION OF ARCHES
STRUCTURAL FUNCTION OF ARCHES - The brick masonry arch has been used to span openings of considerable length in many different applications.
The brick masonry arch has been used to span openings of considerable length in many different applications.
Structural efficiency is attributed to the curvature of the arch, which transfers vertical loads laterally along the arch
to the abutments at each end. The transfer of vertical forces gives rise to both horizontal and vertical reactions at
the abutments. The curvature of the arch and the restraint of the arch by the abutments cause a combination of
flexural stress and axial compression. The arch depth, rise and configuration can be manipulated to keep stresses
primarily compressive. Brick masonry is very strong in compression, so brick masonry arches can support
considerable load. - Historically, arches have been constructed with unreinforced masonry. Most brick masonry arches continue to be
Historically, arches have been constructed with unreinforced masonry. Most brick masonry arches continue to be
built with unreinforced masonry. The structural design of unreinforced brick masonry arches is discussed in
Technical Notes 31A. Very long span arches and arches with a small rise may require steel reinforcement to
resist tensile stresses. Also, reduction in abutment size and arch thickness for economy may require incorporation
of reinforcement for adequate load resistance. Refer to the Technical Notes 17 Series for more information on
reinforced brick masonry. Elaborate and intricate arches are sometimes prefabricated to avoid the complexity of
on-site shoring. Most prefabricated brick masonry arches are reinforced. Prefabricated arches are built off site
and transported to the job or built at the site. Cranes are often used to lift the arch into place in the wall. Such
fabrication, handling and transportation should be considered in the structural design of the arch. Refer to
Technical Notes 40 for a discussion of prefabricated brick masonry.
If an unreinforced or reinforced brick masonry arch is not structurally adequate, the arch will require support.
Typically, this support is provided by a steel angle. This is the most common means of supporting brick masonry
arches in modern construction. The steel angle is bent to the curvature of the intrados of the arch. Curved
sections of steel angle are welded to horizontal steel angles to form a continuous support. The angle either bears
on the brickwork abutments or is attached to a structural member behind the wall. One example is shown in Fig.
4. When an arch is supported by a steel angle, the angle is designed to support the entire weight of brick masonry
loading the arch, and the structural resistance of the arch is neglected. Consult Technical Notes 31B Revised for
a discussion of the structural design of steel angle lintels.
Arch Supported by Curved Steel Angle - FIG. 4
FIG. 4 - WEATHER RESISTANCE
WEATHER RESISTANCE - Water penetration resistance is a primary concern in most applications of the building arch. In the past, the mass
Water penetration resistance is a primary concern in most applications of the building arch. In the past, the mass
of a multi-wythe brick masonry arch was sufficient to resist water penetration. Today, thinner wall sections are
used to minimize material use for economy and efficiency. Still, the arch must provide an effective weather
resistant facade. Some arch applications do not require provisions for water penetration and insulation. For
example, arch arcades and arches supported by porch columns typically do not conceal a direct path for water
migration to the interior of the building they serve and may not require insulation. If this is the case, provisions for
weather resistance need not be included in the arch design and detailing.
Preventing water entry at an arch in an exterior building wall is just as important as at any other wall opening.
Water penetration resistance can be provided by using a barrier wall system or a drainage wall system. Refer to
Technical Notes 7 Revised for definitions and discussion of barrier and drainage wall systems. A drainage wall
system, such as a brick veneer or cavity wall, is the most common brick masonry wall system used today. For
either wall system, the arch should be flashed, with weep holes provided above all flashing locations.
Flashing and Weep Holes - Installation of flashing and weep holes around an arch can be difficult. Installation of flashing is easiest with jack
Installation of flashing and weep holes around an arch can be difficult. Installation of flashing is easiest with jack
arches because they are flat or nearly flat. Flashing should be installed below the arch and above the window
framing or steel angle lintel. Flashing should extend a minimum of 4 in. (100 mm) past the wall opening at either
end and should be turned up to form end dams. This is often termed tray flashing. Weep holes should be provided
at both ends of the flashing and should be placed at a maximum spacing of 24 in. (600 mm) on centers along the
arch span, or 16 in. (400 mm) if rope wicks are used. An example of flashing a jack arch in this manner is shown
in Fig. 5a. Attachment of the flashing to the backing and formation of end dams should follow standard
procedures. If the arch is constructed with reinforced brick masonry, flashing and weep holes can be placed in the
first masonry course above the arch. - Flashing Arches
Flashing Arches - FIG. 5a
FIG. 5a - Flashing Arches
Flashing Arches - FIG. 5b
FIG. 5b - Flashing Arches
Flashing Arches - FIG. 5c
FIG. 5c - Installation of flashing with other arch types, such as segmental and semicircular arches, can be more difficult.
Installation of flashing with other arch types, such as segmental and semicircular arches, can be more difficult.
This is because most rigid flashing materials are hard to bend around an arch with tight curvature. If the arch span
is less than about 3 ft (0.9 m), one section of tray flashing can be placed in the first horizontal mortar joint above
the keystone, as illustrated in Fig. 5b. For arch spans greater than 3 ft (0.9 m), flashing can be bent along the
curve of the arch with overlapping sections, as illustrated in Fig. 4. Alternately, a combination of stepped and tray
flashing can be used, as shown in Fig. 5c. To form a step, the end nearest the arch should be turned up to form
an end dam, while the opposite end is laid flat. A minimum of No. 15 building paper or equivalent moisture
resistant protection should be installed on the exterior face of the backing over the full height of the arch and
abutments. The building paper or equivalent should overlap the arch flashing.
The design of a structural masonry arch should include consideration of the effect of flashing on the strength of
the arch. Flashing acts as a bond break. If flashing is installed above the arch, the loading on the arch will likely
be increased, and the structural resistance of the arch will be reduced. Installation of flashing at the abutments will
affect their structural resistance and should also be considered. Consult Technical Notes 31A for a more
extensive discussion of arch loads and structural resistance of brick masonry arches.
DETAILING CONSIDERATIONS - The brick masonry arch should serve its structural purpose and also provide an attractive architectural element to
The brick masonry arch should serve its structural purpose and also provide an attractive architectural element to
complement its surrounding structure. Careful consideration should be given to the options available for the arch,
soffit and skewback. Proper configuration of the abutments and location of expansion joints should be considered
for any arch design. - Arch
Arch - Arches can be configured in a variety of arch depths, brick sizes and shapes and bonding patterns. The arch is
Arches can be configured in a variety of arch depths, brick sizes and shapes and bonding patterns. The arch is
normally composed of an odd number of units for aesthetic purposes. Some of the more common arch
configurations are illustrated in Fig. 6. Arch voussoirs are typically laid in radial orientation and are most often of
similar size and color to the surrounding brickwork. However, the arch can be formed with brick which are thinner
or wider than the surrounding brickwork and of a different color for variation. Another variation is to project or
recess rings of multiple-ring arches to provide shadow lines or a label course.
Typical Arch Configurations - FIG. 6
FIG. 6 - Brick masonry arches are constructed with two different types of units. The first is tapered or wedge-shaped brick.
Brick masonry arches are constructed with two different types of units. The first is tapered or wedge-shaped brick.
These brick are tapered in the appropriate manner to obtain mortar joints of uniform thickness along the arch
depth. The second is uncut, rectangular brick. When rectangular brick are used, the mortar joints are tapered to
obtain the desired arch curvature. In some cases, a combination of these is used. For example, a slanted arch is
formed with a tapered keystone and rectangular brick. This arch is similar to a jack arch, but can be more
economical because it requires only one special-shaped brick.
Selection of tapered or rectangular brick can be determined by the arch type, arch dimensions and by the
appearance desired. Some arch types require more unique shapes and sizes of brick if uniform mortar joint
thickness is desired. For example, the brick in a traditional jack arch or elliptical arch are all different sizes and
shapes from the abutment to the keystone. Conversely, the voussoirs of a semicircular arch are all the same size
and shape. Arch types with many different brick shapes and sizes should be special ordered from the brick
manufacturer rather than cut in the field. - The arch span should also be considered when selecting the arch brick. For short arch spans, use of tapered
The arch span should also be considered when selecting the arch brick. For short arch spans, use of tapered
brick is recommended to avoid excessively wide mortar joints at the extrados. Larger span arches require less
taper of the voussoirs and, consequently, can be formed with rectangular brick and tapered mortar joints. The
thickness of mortar joints between arch brick should be a maximum of 3/4 in. (19 mm) and a minimum of 1/8 in. (3
mm). When using mortar joints thinner than 1/4 in. (6 mm), consideration should be given to the use of very
uniform brick that meet the dimensional tolerance limits of ASTM C 216, Type FBX, or the use of gauged
brickwork. Refer to Table 1 for determination of the minimum segmental and semicircular arch radii permitted for
rectangular brick and tapered mortar joints. Typically, the use of tapered brick and uniform thickness mortar joints
will be more aesthetically appealing. - 1
1 - Based on 1/4 in. (6 mm) mortar joint width at the intrados and 1/2 in. (13 mm) mortar joint width
Based on 1/4 in. (6 mm) mortar joint width at the intrados and 1/2 in. (13 mm) mortar joint width
at the extrados. If the mortar joint thickness at the extrados is 3/4 in. (19 mm), divide minimum
radius value by 2. - 2
2 - 1 in.=25.4 mm; 1 ft=0.3m
1 in.=25.4 mm; 1 ft=0.3m
Depth. The arch depth will depend upon the size and orientation of the brick used to form the arch. Typically, the
arch depth is a multiple of the brick's width. For structural arches, a minimum arch depth is determined from the
structural requirements. If the arch is supported by a lintel, any arch depth may be used.
The depth of the arch should also be detailed based on the scale of the arch in relation to the scale of the building
and surrounding brickwork. To provide proper visual balance and scale, the arch depth should increase with
increasing arch span. Because aesthetics of an arch are subjective, there are no hard rules for this. However, the
following rules-of-thumb will help provide an arch with proper scale. For segmental and semicircular arches, the
arch depth should equal or exceed 1 in. (25 mm) for every foot (300 mm) of arch span or 4 in. (100 mm),
whichever is greater. For jack arches, the arch depth should equal or exceed 4 in. (100 mm) plus 1 in. (25 mm) for
every foot (300 mm) of arch span or 8 in. (200 mm), whichever is greater. For example, the minimum arch depth
for an 8 ft (2.4 m) span should be 8 in. (200 mm) for segmental arches and 12 in. (300 mm) for jack arches.
The depth of jack arches will also be a function of the coursing of the surrounding brick masonry. The springing
and the extrados of the jack arch should coincide with horizontal mortar joints in the surrounding brick masonry.
Typically, the depth of a jack arch will equal the height of 3, 4 or 5 courses of the surrounding brickwork,
depending upon the course height. - Keystone. The keystone may be a single brick, multiple brick, stone, precast concrete or terra cotta. Avoid using
Keystone. The keystone may be a single brick, multiple brick, stone, precast concrete or terra cotta. Avoid using
a keystone which is much taller than the adjacent voussoirs. A rule-of-thumb is that the keystone should not
extend above adjacent arch brick by more than one third the arch depth. When a keystone is used that is larger
than adjacent arch brick or formed with different material, one option is to use springers that match the keystone.
The use of a large keystone has its basis in both purpose and visual effect. With most arch types, the likely
location of the first crack when the arch fails is at the mortar joint nearest to the midspan of the arch. Use of a
large keystone at this point moves the first mortar joint further from the midspan and increases the resistance to
cracking at this point. Aesthetically, a large keystone adds variation of scale and can introduce other masonry
materials in the facade for additional color and texture.
If the keystone is formed with more than one masonry unit, avoid placing the smaller unit at the bottom. Such
units are more likely to slip when the arch settles under load. Also, it is preferred to have the arch crown (the top
of the keystone) coincident with a horizontal mortar joint in the surrounding brickwork to give the arch a neater
appearance. - Soffit
Soffit - A brick masonry soffit is one attractive feature of a structural brick masonry arch. Many bonding patterns and
A brick masonry soffit is one attractive feature of a structural brick masonry arch. Many bonding patterns and
arrangements can be used to form the arch soffit. Deep soffits are common on building arcades or arched
entranceways. In this case, it is common to form a U-shaped wall section, as illustrated in Fig. 7. The arches on
either wall face should be bonded to the brick masonry forming the soffit. Bonding pattern or metal ties should be
used to tie the brick masonry forming the soffit together structurally and to tie the arches on either wall face to the
soffit. If metal ties are used to bond the masonry, corrosion resistant box or Z metal wire ties should be placed
along the arch span at a maximum spacing of 24 in. (600 mm) on center.
Structural resistance of the arch should be evaluated at sections through the soffit, the exterior wall face and the
interior wall face. Deeper soffits may require an increase in arch depth. If the arch is structural, connection of the
brick masonry forming the soffit to interior framing members with wall ties or connectors may not be required.
Structural Arch Soffit Option - FIG. 7
FIG. 7 - Skewback
Skewback - For flat arches and arch types that have horizontal skewbacks, such as jack and semicircular arches,
For flat arches and arch types that have horizontal skewbacks, such as jack and semicircular arches,
respectively, the most desirable spring line location is coincident with a bed joint in the abutment. For other arch
types, it is preferred to have the spring line pass about midway through a brick course in the abutment, as
illustrated in Fig. 8, to avoid a thick mortar joint at the springing. The brick in the abutment at the springing should
be cut or be a special cant-shaped brick. This allows vertical alignment with the brick beneath, producing more
accurate alignment of the arch. - When two arches are adjacent, such as with a two-bay garage or building arcades, intersection of the arches may
When two arches are adjacent, such as with a two-bay garage or building arcades, intersection of the arches may
occur at the skewback. Attention should be given to proper bonding of the arches for both visual appeal and
structural bonding. Creation of a vertical line between arches should be avoided. Rather, special shape brick
should be used to mesh the two arches properly. One example is illustrated in Fig. 9.
Skewback Options - FIG. 8
FIG. 8 - Option For Intersecting Arches
Option For Intersecting Arches - FIG. 9
FIG. 9 - Abutments
Abutments - An arch abutment can be a column, wall or combination of wall and shelf angle. Failure of an abutment occurs
An arch abutment can be a column, wall or combination of wall and shelf angle. Failure of an abutment occurs
from excessive lateral movement of the abutment or exceeding the flexural, compressive or shear strength of the
abutment. Lateral movement of the abutment is due to the horizontal thrust of the arch. Thrust develops in all
arches and the thrust force is greater for flatter arches. The thrust should be resisted so that lateral movement of
the abutment does not cause failure in the arch. If the abutment is formed by a combination of brickwork and a
non-masonry structural member, rigidity of the non-masonry structural member and rigidity of the ties are very
important. Adjustable ties or single or double wire ties are recommended. Corrugated ties should not be used in
this application because they do not provide adequate axial stiffness. Consult Technical Notes 31A for further
discussion of abutment and tie stiffness requirements. - Lateral Bracing
Lateral Bracing - In addition to gravity loads, out-of-plane loads should be considered when designing a masonry arch. The arch
In addition to gravity loads, out-of-plane loads should be considered when designing a masonry arch. The arch
should have adequate resistance to out-of-plane loads or lateral bracing should be provided. In veneer
construction, lateral bracing is provided by the backing through the use of wall ties. Arches which are not laterally
braced may require increased masonry thickness or reinforcement to carry loads perpendicular to the arch plane
in addition to vertical loads. - Expansion Joints
Expansion Joints - Thermal and moisture movements of brick masonry are controlled by the use of expansion joints. Expansion
Thermal and moisture movements of brick masonry are controlled by the use of expansion joints. Expansion
joints avoid cracking of the brickwork and also reduce the size of wall sections. Reduction of wall size has a very
important effect upon the performance of structural brick masonry arches. The state of stress in a structural brick
arch and the surrounding masonry is very sensitive to the relative movements of the abutments. If an inadequate
number of expansion joints are provided, the differential movement of abutments can cause cracking and
downward displacement of brick in the masonry arch and surrounding masonry. Proper size and spacing of
expansion joints is discussed in Technical Notes 18A Revised.
If the arch is structural, care should be taken not to affect the integrity of the arch by detailing expansion joints too
close to the arch and its abutments. Vertical expansion joints should not be placed in the masonry directly above
a structural arch. This region of masonry is in compression, so an expansion joint will cause displacement when
centering is removed and possible collapse of the arch and surrounding brickwork. In addition, vertical expansion
joints should not be placed in close proximity to the springing. The expansion joint will reduce the effective width
of the abutment and its ability to resist horizontal thrust from the arch. If the arch is non-structural, placement of
expansion joints may be at the arch crown and also at a sufficient distance away from the springing to avoid
sliding. While permitted, placement of an expansion joint at the arch crown is not preferred because it disrupts
ones traditional view of the arch as a structural element. Refer to Fig. 10 for suggested expansion joint locations
for structural and non-structural arches. - Expansion Joints Near Arches
Expansion Joints Near Arches - FIG. 10a
FIG. 10a - Expansion Joints Near Arches
Expansion Joints Near Arches - FIG. 10b
FIG. 10b - Detailing of expansion joints can be difficult with very long span arches or runs of multiple arches along an
Detailing of expansion joints can be difficult with very long span arches or runs of multiple arches along an
arcade. Structural analysis of the arch should consider the location of expansion joints. For the particular case of
multiple arches closely spaced, vertical expansion joints should be detailed at a sufficient distance away from the
end arches so that horizontal arch thrusts are adequately resisted by the abutments to avoid overturning of the
abutments. For long arcades, expansion joints should also be placed along the centerline of abutments between
arches when necessary. In this case, horizontal thrusts from adjacent arches will not be counteracting, so the
effective abutment length should be halved and overturning of each half of the abutment should be checked.
Refer to Technical Notes 31A for further discussion of abutment design for adequate stiffness.
MATERIAL SELECTION - To provide a weather resistant barrier and maintain its structural resistance, the arch must be constructed with
To provide a weather resistant barrier and maintain its structural resistance, the arch must be constructed with
durable materials. The strength of an arch depends upon the compressive strength and the flexural tensile
strength of the masonry. Selection of brick and mortar should consider these properties.
Brick - Solid or hollow clay brick may be used to form the arch and the surrounding brickwork. Solid brick should comply
Solid or hollow clay brick may be used to form the arch and the surrounding brickwork. Solid brick should comply
with the requirements of ASTM C 216 Specification for Facing Brick. Hollow brick should comply with the
requirements of ASTM C 652 Specification for Hollow Brick. Refer to Technical Notes 9 Series for a discussion of
brick selection and classification. The compressive strength of masonry is related to the compressive strength of
the brick, the mortar type and the grout strength. For structural arches, brick should be selected with
consideration of the required compressive strength of masonry. Typically, compressive strength of the brick
masonry will not limit the design of the arch.
Tapered voussoirs can be cut from rectangular units at the job site or special ordered from the brick manufacturer.
Before specifying manufactured special arch shapes, the designer should determine the availability of special
shapes for the arch type and brick color and texture desired. Many brick manufacturers produce tapered arch
brick for the more common arch types as part of their regular stock of special shapes. Be sure to contact the
manufacturer as early as possible if special shapes are needed. In many instances, production of the special
shapes may require a color matching process and adequate lead time for the manufacturer.
Mortar - Mortar used to construct brick masonry arches should meet the requirements of ASTM C 270 Standard
Mortar used to construct brick masonry arches should meet the requirements of ASTM C 270 Standard
Specification for Masonry Mortar. Consult Technical Notes 8 Series for a discussion of mortar types and kinds for
brick masonry. For structural arches, the flexural tensile strength of the masonry should be considered when
selecting the mortar. The flexural tensile strength of the masonry will affect the load resistance of the arch and the
abutments. - CONSTRUCTION AND WORKMANSHIP
CONSTRUCTION AND WORKMANSHIP - The proper performance of a brick masonry arch depends upon proper methods of construction and attention to
The proper performance of a brick masonry arch depends upon proper methods of construction and attention to
workmanship. Layout of the arch prior to construction will help avoid poor spacing of voussoirs, which results in
thicker mortar joints and unsymmetrical arches. Some arch applications, such as barrel vaults and domes, can be
entirely self-supporting, even during construction. However, most applications of the masonry arch used today
require proper shoring and bracing. - Centering
Centering - Both structural and non-structural arches should be properly supported throughout construction. Brick masonry
Both structural and non-structural arches should be properly supported throughout construction. Brick masonry
arches are constructed with the aid of temporary shoring, termed centering, or permanent supports, such as a
structural steel angle. - Centering is used to carry the weight of a brick masonry arch and the loads being supported by the arch until the
Centering is used to carry the weight of a brick masonry arch and the loads being supported by the arch until the
arch itself has gained sufficient strength. The term "centering" is used because the shoring is marked for proper
positioning of the brick forming the arch. Centering is typically provided by wood construction. An example of
centering for an arch is shown in Fig. 11. Careful construction of the centering will ensure a more pleasing arch
appearance and avoid layout problems, such as an uneven number of brick to either side of the keystone.
Centering - FIG. 11
FIG. 11 - Immediately after placement of the keystone, very slight downward displacement of the centering, termed easing,
Immediately after placement of the keystone, very slight downward displacement of the centering, termed easing,
can be performed to cause the arch voussoirs to press against one another and compress the mortar joints
between them. Easing helps to avoid separation cracks in the arch. In no case should centering be removed until
it is certain that the masonry is capable of carrying all imposed loads. Premature removal of the centering may
result in collapse of the arch. - Centering should remain in place for at least seven days after construction of the arch. Longer curing periods may
Centering should remain in place for at least seven days after construction of the arch. Longer curing periods may
be required when the arch is constructed in cold weather conditions and when required for structural reasons. The
arch loading and the structural resistance of the arch will depend upon the amount of brickwork surrounding the
arch, particularly the brick masonry within spandrel areas. Appropriate time of removal of centering for a structural
arch should be determined with consideration of the assumptions made in the structural analysis of the arch. It
may be necessary to wait until the brickwork above the arch has also cured before removing the centering.
Workmanship - All mortar joints should be completely filled, especially in a structural member such as an arch. If hollow brick are
All mortar joints should be completely filled, especially in a structural member such as an arch. If hollow brick are
used to form the arch, it is very important that all face shells and end webs are completely filled with mortar. Brick
masonry arches are sometimes constructed with the units laid in a soldier orientation. It may be difficult to lay
units in a soldier position and also obtain completely filled mortar joints. This is especially true for an arch with
tapered mortar joints. In such cases, the use of two or more rings of arch brick laid in rowlock orientation can help
ensure full mortar joints. - SUMMARY
SUMMARY - This Technical Notes is an introduction to brick masonry arches. A glossary of arch terms has been provided.
This Technical Notes is an introduction to brick masonry arches. A glossary of arch terms has been provided.
Many different types of brick masonry arches are described and illustrated. Proper detailing of brick masonry
arches for appearance, structural support and weather resistance is discussed. Material selection and proper
construction practices are explained. Other Technical Notes in this Series discuss the structural design of arches.
The information and suggestions contained in this Technical Notes are based on the available data and the
experience of the engineering staff of the Brick Industry Association. The information contained herein must be
used in conjunction with good technical judgment and a basic understanding of the properties of brick masonry.
Final decisions on the use of the information contained in this Technical Notes are not within the purview of the
Brick Industry Association and must rest with the project architect, engineer and owner.
REFERENCES - 1. Brickwork Arch Detailing, Ibstock Building Products, Butterworth & Co. (Publishers) Ltd., London,
1. Brickwork Arch Detailing, Ibstock Building Products, Butterworth & Co. (Publishers) Ltd., London,
England, 1989, 114 pp. - 2. Lynch, G., Gauged Brickwork, A Technical Handbook, Gower Publishing Company, Aldershot, Hants,
2. Lynch, G., Gauged Brickwork, A Technical Handbook, Gower Publishing Company, Aldershot, Hants,
England, 1990, 115 pp. - 3. Trimble, B.E., and Borchelt, J.G., "Jack Arches in Masonry Construction," The Construction Specifier,
3. Trimble, B.E., and Borchelt, J.G., "Jack Arches in Masonry Construction," The Construction Specifier,
Construction Specifications Institute, Alexandria, VA, January 1991, pp. 62-65.
Complexity characterises the behaviour of a system or model whose components interact in multiple ways and follow local rules, meaning there is no reasonable higher instruction to define the various possible interactions.[1]
The term is generally used to characterize something with many parts where those parts interact with each other in multiple ways, culminating in a higher order of emergence greater than the sum of its parts. The study of these complex linkages at various scales is the main goal of complex systems theory.
Science as of 2010[update] takes a number of approaches to characterizing complexity; Zayed et al.[2] reflect many of these. Neil Johnson states that "even among scientists, there is no unique definition of complexity and the scientific notion has traditionally been conveyed using particular examples..." Ultimately Johnson adopts the definition of "complexity science" as "the study of the phenomena which emerge from a collection of interacting objects".[3]
Definitions of complexity often depend on the concept of a "system" a set of parts or elements that have relationships among them differentiated from relationships with other elements outside the relational regime. Many definitions tend to postulate or assume that complexity expresses a condition of numerous elements in a system and numerous forms of relationships among the elements. However, what one sees as complex and what one sees as simple is relative and changes with time.
Warren Weaver posited in 1948 two forms of complexity: disorganized complexity, and organized complexity.[4] Phenomena of 'disorganized complexity' are treated using probability theory and statistical mechanics, while 'organized complexity' deals with phenomena that escape such approaches and confront "dealing simultaneously with a sizable number of factors which are interrelated into an organic whole".[4] Weaver's 1948 paper has influenced subsequent thinking about complexity.[5]
The approaches that embody concepts of systems, multiple elements, multiple relational regimes, and state spaces might be summarized as implying that complexity arises from the number of distinguishable relational regimes (and their associated state spaces) in a defined system.
Some definitions relate to the algorithmic basis for the expression of a complex phenomenon or model or mathematical expression, as later set out herein.
One of the problems in addressing complexity issues has been formalizing the intuitive conceptual distinction between the large number of variances in relationships extant in random collections, and the sometimes large, but smaller, number of relationships between elements in systems where constraints (related to correlation of otherwise independent elements) simultaneously reduce the variations from element independence and create distinguishable regimes of more-uniform, or correlated, relationships, or interactions.
Weaver perceived and addressed this problem, in at least a preliminary way, in drawing a distinction between "disorganized complexity" and "organized complexity".
In Weaver's view, disorganized complexity results from the particular system having a very large number of parts, say millions of parts, or many more. Though the interactions of the parts in a "disorganized complexity" situation can be seen as largely random, the properties of the system as a whole can be understood by using probability and statistical methods.
A prime example of disorganized complexity is a gas in a container, with the gas molecules as the parts. Some would suggest that a system of disorganized complexity may be compared with the (relative) simplicity of planetary orbits the latter can be predicted by applying Newton's laws of motion. Of course, most real-world systems, including planetary orbits, eventually become theoretically unpredictable even using Newtonian dynamics; as discovered by modern chaos theory.[6]
Organized complexity, in Weaver's view, resides in nothing else than the non-random, or correlated, interaction between the parts. These correlated relationships create a differentiated structure that can, as a system, interact with other systems. The coordinated system manifests properties not carried or dictated by individual parts. The organized aspect of this form of complexity vis-a-vis to other systems than the subject system can be said to "emerge," without any "guiding hand".
The number of parts does not have to be very large for a particular system to have emergent properties. A system of organized complexity may be understood in its properties (behavior among the properties) through modeling and simulation, particularly modeling and simulation with computers. An example of organized complexity is a city neighborhood as a living mechanism, with the neighborhood people among the system's parts.[7]
There are generally rules which can be invoked to explain the origin of complexity in a given system.
The source of disorganized complexity is the large number of parts in the system of interest, and the lack of correlation between elements in the system.
In the case of self-organizing living systems, usefully organized complexity comes from beneficially mutated organisms being selected to survive by their environment for their differential reproductive ability or at least success over inanimate matter or less organized complex organisms. See e.g. Robert Ulanowicz's treatment of ecosystems.[8]
Complexity of an object or system is a relative property. For instance, for many functions (problems), such a computational complexity as time of computation is smaller when multitape Turing machines are used than when Turing machines with one tape are used. Random Access Machines allow one to even more decrease time complexity (Greenlaw and Hoover 1998: 226), while inductive Turing machines can decrease even the complexity class of a function, language or set (Burgin 2005). This shows that tools of activity can be an important factor of complexity.
In several scientific fields, "complexity" has a precise meaning:
In computational complexity theory, the amounts of resources required for the execution of algorithms is studied. The most popular types of computational complexity are the time complexity of a problem equal to the number of steps that it takes to solve an instance of the problem as a function of the size of the input (usually measured in bits), using the most efficient algorithm, and the space complexity of a problem equal to the volume of the memory used by the algorithm (e.g., cells of the tape) that it takes to solve an instance of the problem as a function of the size of the input (usually measured in bits), using the most efficient algorithm. This allows classification of computational problems by complexity class (such as P, NP, etc.). An axiomatic approach to computational complexity was developed by Manuel Blum. It allows one to deduce many properties of concrete computational complexity measures, such as time complexity or space complexity, from properties of axiomatically defined measures.
In algorithmic information theory, the Kolmogorov complexity (also called descriptive complexity, algorithmic complexity or algorithmic entropy) of a string is the length of the shortest binary program that outputs that string. Minimum message length is a practical application of this approach. Different kinds of Kolmogorov complexity are studied: the uniform complexity, prefix complexity, monotone complexity, time-bounded Kolmogorov complexity, and space-bounded Kolmogorov complexity. An axiomatic approach to Kolmogorov complexity based on Blum axioms (Blum 1967) was introduced by Mark Burgin in the paper presented for publication by Andrey Kolmogorov.[9] The axiomatic approach encompasses other approaches to Kolmogorov complexity. It is possible to treat different kinds of Kolmogorov complexity as particular cases of axiomatically defined generalized Kolmogorov complexity. Instead of proving similar theorems, such as the basic invariance theorem, for each particular measure, it is possible to easily deduce all such results from one corresponding theorem proved in the axiomatic setting. This is a general advantage of the axiomatic approach in mathematics. The axiomatic approach to Kolmogorov complexity was further developed in the book (Burgin 2005) and applied to software metrics (Burgin and Debnath, 2003; Debnath and Burgin, 2003).
In information processing, complexity is a measure of the total number of properties transmitted by an object and detected by an observer. Such a collection of properties is often referred to as a state.
In physical systems, complexity is a measure of the probability of the state vector of the system. This should not be confused with entropy; it is a distinct mathematical measure, one in which two distinct states are never conflated and considered equal, as is done for the notion of entropy in statistical mechanics.
In dynamical systems, statistical complexity measures the size of the minimum program able to statistically reproduce the patterns (configurations) contained in the data set (sequence).[10][11] While the algorithmic complexity implies a deterministic description of an object (it measures the information content of an individual sequence), the statistical complexity, like forecasting complexity,[12] implies a statistical description, and refers to an ensemble of sequences generated by a certain source. Formally, the statistical complexity reconstructs a minimal model comprising the collection of all histories sharing a similar probabilistic future, and measures the entropy of the probability distribution of the states within this model. It is a computable and observer-independent measure based only on the internal dynamics of the system, and has been used in studies of emergence and self-organization.[13]
In Network theory complexity is the product of richness in the connections between components of a system,[14] and defined by a very unequal distribution of certain measures (some elements being highly connected and some very few, see complex network).
In software engineering, programming complexity is a measure of the interactions of the various elements of the software. This differs from the computational complexity described above in that it is a measure of the design of the software.
In abstract sense Abstract Complexity, is based on visual structures perception[15] It is complexity of binary string defined as a square of features number divided by number of elements (0's and 1's). Features comprise here all distinctive arrangements of 0's and 1's. Though the features number have to be always approximated the definition is precise and meet intuitive criterion.
Other fields introduce less precisely defined notions of complexity:
The number of parts (and types of parts) in the system and the number of relations between the parts is non-trivial however, there is no general rule to separate "trivial" from "non-trivial";
The system can adapt itself according to its history or feedback;
The relations between the system and its environment are non-trivial or non-linear;
The system can be influenced by, or can adapt itself to, its environment;
The system is highly sensitive to initial conditions.
Complexity has always been a part of our environment, and therefore many scientific fields have dealt with complex systems and phenomena. From one perspective, that which is somehow complex displaying variation without being random is most worthy of interest given the rewards found in the depths of exploration.
The use of the term complex is often confused with the term complicated. In today's systems, this is the difference between myriad connecting "stovepipes" and effective "integrated" solutions.[16] This means that complex is the opposite of independent, while complicated is the opposite of simple.
While this has led some fields to come up with specific definitions of complexity, there is a more recent movement to regroup observations from different fields to study complexity in itself, whether it appears in anthills, human brains, or stock markets, social systems.[17] One such interdisciplinary group of fields is relational order theories.
The behavior of a complex system is often said to be due to emergence and self-organization. Chaos theory has investigated the sensitivity of systems to variations in initial conditions as one cause of complex behaviour.
In social science, the study on the emergence of macro-properties from the micro-properties, also known as macro-micro view in sociology. The topic is commonly recognized as social complexity that is often related to the use of computer simulation in social science, i.e.: computational sociology.
Systems theory has long been concerned with the study of complex systems (in recent times, complexity theory and complex systems have also been used as names of the field). These systems are present in the research of a variety disciplines, including biology, economics, social studies and technology. Recently, complexity has become a natural domain of interest of real world socio-cognitive systems and emerging systemics research. Complex systems tend to be high-dimensional, non-linear, and difficult to model. In specific circumstances, they may exhibit low-dimensional behaviour.
In information theory, algorithmic information theory is concerned with the complexity of strings of data.
Complex strings are harder to compress. While intuition tells us that this may depend on the codec used to compress a string (a codec could be theoretically created in any arbitrary language, including one in which the very small command "X" could cause the computer to output a very complicated string like "18995316"), any two Turing-complete languages can be implemented in each other, meaning that the length of two encodings in different languages will vary by at most the length of the "translation" language which will end up being negligible for sufficiently large data strings.
These algorithmic measures of complexity tend to assign high values to random noise. However, those studying complex systems would not consider randomness as complexity[who?].
Information entropy is also sometimes used in information theory as indicative of complexity, but entropy is also high for randomness. Information fluctuation complexity, fluctuations of information about entropy, does not consider randomness to be complex and has been useful in many applications.
the overlaps in feature values from differing classes.
the separability of the classes. - measures of geometry, topology, and density of manifolds. Instance hardness is another approach seeks to characterize the data complexity with the goal of determining how hard a data set is to classify correctly and is not limited to binary problems.[19]
measures of geometry, topology, and density of manifolds. Instance hardness is another approach seeks to characterize the data complexity with the goal of determining how hard a data set is to classify correctly and is not limited to binary problems.[19]
Instance hardness is a bottom-up approach that first seeks to identify instances that are likely to be misclassified (or, in other words, which instances are the most complex). The characteristics of the instances that are likely to be misclassified are then measured based on the output from a set of hardness measures. The hardness measures are based on several supervised learning techniques such as measuring the number of disagreeing neighbors or the likelihood of the assigned class label given the input features. The information provided by the complexity measures has been examined for use in meta learning to determine for which data sets filtering (or removing suspected noisy instances from the training set) is the most beneficial[20] and could be expanded to other areas.
A recent study based on molecular simulations and compliance constants describes molecular recognition as a phenomenon of organisation.[21] Even for small molecules like carbohydrates, the recognition process can not be predicted or designed even assuming that each individual hydrogen bond's strength is exactly known.
Driving from the law of requisite variety, Boisot and McKelvey formulated the Law of Requisite Complexity, that holds that, in order to be efficaciously adaptive, the internal complexity of a system must match the external complexity it confronts. [22] The application in project management of the Law of Requisite Complexity is the analysis of positive, appropriate and positive complexity.
Project complexity is the property of a project which makes it difficult to understand, foresee, and keep under control its overall behavior, even when given reasonably complete information about the project system.[23][24]
Computational complexity theory is the study of the complexity of problems that is, the difficulty of solving them. Problems can be classified by complexity class according to the time it takes for an algorithm usually a computer program to solve them as a function of the problem size. Some problems are difficult to solve, while others are easy. For example, some difficult problems need algorithms that take an exponential amount of time in terms of the size of the problem to solve. Take the travelling salesman problem, for example. It can be solved in time O ( n 2 2 n ) {\displaystyle O(n^{2}2^{n})} (where n is the size of the network to visit the number of cities the travelling salesman must visit exactly once). As the size of the network of cities grows, the time needed to find the route grows (more than) exponentially.
Even though a problem may be computationally solvable in principle, in actual practice it may not be that simple. These problems might require large amounts of time or an inordinate amount of space. Computational complexity may be approached from many different aspects. Computational complexity can be investigated on the basis of time, memory or other resources used to solve the problem. Time and space are two of the most important and popular considerations when problems of complexity are analyzed.
There exist a certain class of problems that although they are solvable in principle they require so much time or space that it is not practical to attempt to solve them. These problems are called intractable.
There is another form of complexity called hierarchical complexity. It is orthogonal to the forms of complexity discussed so far, which are called horizontal complexity.
^ J. M. Zayed, N. Nouvel, U. Rauwald, O. A. Scherman. Chemical Complexity supramolecular self-assembly of synthetic and biological building blocks in water. Chemical Society Reviews, 2010, 39, 28062816 http://pubs.rsc.org/en/Content/ArticleLanding/2010/CS/b922348g
^ Ulanowicz, Robert, "Ecology, the Ascendant Perspective", Columbia, 1997
^ Burgin, M. (1982) Generalized Kolmogorov complexity and duality in theory of computations, Notices of the Russian Academy of Sciences, v.25, No. 3, pp. 1923
^ Sez, Jos A.; Luengo, Julin; Herrera, Francisco (2013). "Predicting Noise Filtering Efficacy with Data Complexity Measures for Nearest Neighbor Classification". Pattern Recognition. 46: 355364. doi:10.1016/j.patcog.2012.07.009.
^ Boisot, M.; McKelvey, B. (2011). "Complexity and organization-environment relations: revisiting Ashby's law of requisite variety". P. Allen, The Sage Handbook of Complexity and Management: 279298.
^ Marle, Franck; Vidal, LudovicAlexandre (2016). Managing Complex, High Risk Projects - A Guide to Basic and Advanced Project Management. London: Springer-Verlag.
Sol, R. V.; B. C. Goodwin (2002). Signs of Life: How Complexity Pervades Biology. Basic Books. ISBN 978-0-465-01928-1.
Burgin, M. (1982) Generalized Kolmogorov complexity and duality in theory of computations, Notices of the Russian Academy of Sciences, v.25, No. 3, pp. 1923
Meyers, R.A., (2009) "Encyclopedia of Complexity and Systems Science", ISBN 978-0-387-75888-6
Mitchell, M. (2009). Complexity: A Guided Tour. Oxford University Press, Oxford, UK.
Look up complexity in Wiktionary, the free dictionary.
Complexity Measures an article about the abundance of not-that-useful complexity measures.
What is a door OFFSET? - What is offset? Offset is the center-to-center measurement between Dead bolt Bore and Latch Bore. Offset may vary from door to door, and on custom doors could be drilled out to any specification. However it is recommended that you use 6 inch or 9 inch offsets, but it is up to the description of the installer if the door is not pre-drilled. ONE PIECE ENTRY SET One piece entry sets usually have standard 5-1/2 inch or 6 inch offset, sometimes manufacturer might offer other offset choices and also make custom offset entry sets. Graphic bellow is an example of a one piece entry set with standard offset. TWO PIECE ENTRY SET Two piece entry set is where Dead bolt is a separate part of the entry set and not mounted on the same plate. Bellow is a graphic with a popular 6 inch offset.
What is offset? Offset is the center-to-center measurement between Dead bolt Bore and Latch Bore. Offset may vary from door to door, and on custom doors could be drilled out to any specification. However it is recommended that you use 6 inch or 9 inch offsets, but it is up to the description of the installer if the door is not pre-drilled. ONE PIECE ENTRY SET One piece entry sets usually have standard 5-1/2 inch or 6 inch offset, sometimes manufacturer might offer other offset choices and also make custom offset entry sets. Graphic bellow is an example of a one piece entry set with standard offset. TWO PIECE ENTRY SET Two piece entry set is where Dead bolt is a separate part of the entry set and not mounted on the same plate. Bellow is a graphic with a popular 6 inch offset.
Bellow is a graphic with a popular 9 inch offset. DUMMY SETS require no door prep. Dummy handles are surface mounted and may be located anywhere on the door you choose, but they are usually located to match the appearance of nearby operating locks.
Glossary - The following is a compilation of building energy-code related terms and acronyms used on the Building Energy Codes website and throughout the building construction industry.
The following is a compilation of building energy-code related terms and acronyms used on the Building Energy Codes website and throughout the building construction industry.
Select a letter to navigate through the glossary:
Filter - A (23) B (23) C (41) D (27) E (28) F (15) G (12) H (21) I (20) K (5) L (11) M (16) N (15) O (11) P (21) R (22) S (37) T (14) U (12) V (11) W (10)
A (23) B (23) C (41) D (27) E (28) F (15) G (12) H (21) I (20) K (5) L (11) M (16) N (15) O (11) P (21) R (22) S (37) T (14) U (12) V (11) W (10)
General Lighting - Lighting that provides a substantially uniform level of illumination throughout an area. General lighting shall not include decorative lighting or lighting that provides a dissimilar level of illumination to serve a specialized application or feature within an area.
Lighting that provides a substantially uniform level of illumination throughout an area. General lighting shall not include decorative lighting or lighting that provides a dissimilar level of illumination to serve a specialized application or feature within an area.
General Service Lamp - A class of incandescent lamps that provide light in virtually all directions. General service lamps are typically characterized by bulb shapes such as A, standard; S, straight side; F, flame; G, globe; and PS, pear straight.
A class of incandescent lamps that provide light in virtually all directions. General service lamps are typically characterized by bulb shapes such as A, standard; S, straight side; F, flame; G, globe; and PS, pear straight.
Generally Accepted Engineering Standard - A specification, rule, guide, or procedure in the field of engineering, or related thereto, recognized and accepted as authoritative.
A specification, rule, guide, or procedure in the field of engineering, or related thereto, recognized and accepted as authoritative.
Glazed Wall System - A category of site-assembled fenestration products, which includes, but is not limited to, curtain walls and solariums.
A category of site-assembled fenestration products, which includes, but is not limited to, curtain walls and solariums.
Glazing - Any translucent or transparent material in exterior openings of buildings, including windows, skylights, sliding doors, the glass area of opaque doors, and glass block.
Any translucent or transparent material in exterior openings of buildings, including windows, skylights, sliding doors, the glass area of opaque doors, and glass block.
Glazing Area - The area of a glazing assembly is the interior surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. The nominal area or rough opening is also acceptable for flat windows and doors.
The area of a glazing assembly is the interior surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. The nominal area or rough opening is also acceptable for flat windows and doors.
Glazing U-Factor - Based on the interior-surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. Center-of-glass U-factors cannot be used.
Based on the interior-surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. Center-of-glass U-factors cannot be used.
Grade - The finished ground level adjoining a building at all exterior walls.
The finished ground level adjoining a building at all exterior walls.
Gross Floor Area - The sum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but it excludes covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features.
The sum of the floor areas of the spaces within the building including basements, mezzanine and intermediate-floored tiers, and penthouses with headroom height of 7.5 ft or greater. It is measured from the exterior faces of exterior walls or from the centerline of walls separating buildings, but it excludes covered walkways, open roofed-over areas, porches and similar spaces, pipe trenches, exterior terraces or steps, chimneys, roof overhangs, and similar features.
Gross Wall Area - The gross wall area includes the opaque area of above-grade walls, the opaque area of any individual wall of a conditioned basement less than 50% below grade (including the below-grade portions), all windows and doors (including windows and doors of conditioned basements), and the peripheral edges of floors.
The gross wall area includes the opaque area of above-grade walls, the opaque area of any individual wall of a conditioned basement less than 50% below grade (including the below-grade portions), all windows and doors (including windows and doors of conditioned basements), and the peripheral edges of floors.
Gross Window Area - Includes the rough-opening area of the window, not just the transparent-glass area.
Includes the rough-opening area of the window, not just the transparent-glass area.
Gutter - The space available for wiring inside panel boards and other electric panels; a separate wireway used to supplement wiring spaces in electric panels.
The space available for wiring inside panel boards and other electric panels; a separate wireway used to supplement wiring spaces in electric panels.
The surface area of a solid object is a measure of the total area that the surface of the object occupies.[1] The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc length of one-dimensional curves, or of the surface area for polyhedra (i.e., objects with flat polygonal faces), for which the surface area is the sum of the areas of its faces. Smooth surfaces, such as a sphere, are assigned surface area using their representation as parametric surfaces. This definition of surface area is based on methods of infinitesimal calculus and involves partial derivatives and double integration.
A general definition of surface area was sought by Henri Lebesgue and Hermann Minkowski at the turn of the twentieth century. Their work led to the development of geometric measure theory, which studies various notions of surface area for irregular objects of any dimension. An important example is the Minkowski content of a surface.
Contents - While the areas of many simple surfaces have been known since antiquity, a rigorous mathematical definition of area requires a great deal of care. This should provide a function
While the areas of many simple surfaces have been known since antiquity, a rigorous mathematical definition of area requires a great deal of care. This should provide a function
S A ( S ) {\displaystyle S\mapsto A(S)}
which assigns a positive real number to a certain class of surfaces that satisfies several natural requirements. The most fundamental property of the surface area is its additivity: the area of the whole is the sum of the areas of the parts. More rigorously, if a surface S is a union of finitely many pieces S1, , Sr which do not overlap except at their boundaries, then
A ( S ) = A ( S 1 ) + + A ( S r ) . {\displaystyle A(S)=A(S_{1})+\cdots +A(S_{r}).}
Surface areas of flat polygonal shapes must agree with their geometrically defined area. Since surface area is a geometric notion, areas of congruent surfaces must be the same and the area must depend only on the shape of the surface, but not on its position and orientation in space. This means that surface area is invariant under the group of Euclidean motions. These properties uniquely characterize surface area for a wide class of geometric surfaces called piecewise smooth. Such surfaces consist of finitely many pieces that can be represented in the parametric form
with a continuously differentiable function r . {\displaystyle {\vec {r}}.} The area of an individual piece is defined by the formula
Thus the area of SD is obtained by integrating the length of the normal vector r u r v {\displaystyle {\vec {r}}_{u}\times {\vec {r}}_{v}} to the surface over the appropriate region D in the parametric uv plane. The area of the whole surface is then obtained by adding together the areas of the pieces, using additivity of surface area. The main formula can be specialized to different classes of surfaces, giving, in particular, formulas for areas of graphs z = f(x,y) and surfaces of revolution.
Schwarz lantern with M {\displaystyle M} axial slices and N {\displaystyle N} radial vertices. The limit of the area as M {\displaystyle M} and N {\displaystyle N} tend to infinity doesn't converge. In particular it doesn't converge to the area of the cylinder.
One of the subtleties of surface area, as compared to arc length of curves, is that surface area cannot be defined simply as the limit of areas of polyhedral shapes approximating a given smooth surface. It was demonstrated by Hermann Schwarz that already for the cylinder, different choices of approximating flat surfaces can lead to different limiting values of the area; this example is known as the Schwarz lantern.[2][3]
Various approaches to a general definition of surface area were developed in the late nineteenth and the early twentieth century by Henri Lebesgue and Hermann Minkowski. While for piecewise smooth surfaces there is a unique natural notion of surface area, if a surface is very irregular, or rough, then it may not be possible to assign an area to it at all. A typical example is given by a surface with spikes spread throughout in a dense fashion. Many surfaces of this type occur in the study of fractals. Extensions of the notion of area which partially fulfill its function and may be defined even for very badly irregular surfaces are studied in geometric measure theory. A specific example of such an extension is the Minkowski content of the surface.
b = base length of triangle, h = height of triangle, l = distance between triangular bases, p, q, r = sides of triangle
r = minor radius (radius of the tube), R = major radius (distance from center of tube to center of torus)
s = slant height of the cone, r = radius of the circular base, h = height of the cone
D | r u r v | d A {\displaystyle \iint \limits _{D}\left\vert {\vec {r}}_{u}\times {\vec {r}}_{v}\right\vert dA}
r {\displaystyle {\vec {r}}} = parametric vector equation of surface
r u {\displaystyle {\vec {r}}_{u}} = partial derivative of r {\displaystyle {\vec {r}}} with respect to u {\displaystyle u}
r v {\displaystyle {\vec {r}}_{v}} = partial derivative of r {\displaystyle {\vec {r}}} with respect to v {\displaystyle v}
D {\displaystyle D} = shadow region
Ratio of surface areas of a sphere and cylinder of the same radius and height[edit]
A cone, sphere and cylinder of radius r and height h.
The below given formulas can be used to show that the surface area of a sphere and cylinder of the same radius and height are in the ratio 2 : 3, as follows.
Let the radius be r and the height be h (which is 2r for the sphere).
Sphere surface area = 4 r 2 = ( 2 r 2 ) 2 Cylinder surface area = 2 r ( h + r ) = 2 r ( 2 r + r ) = ( 2 r 2 ) 3 {\displaystyle {\begin{array}{rlll}{\text{Sphere surface area}}&=4\pi r^{2}&&=(2\pi r^{2})\times 2\\{\text{Cylinder surface area}}&=2\pi r(h+r)&=2\pi r(2r+r)&=(2\pi r^{2})\times 3\end{array}}}
The discovery of this ratio is credited to Archimedes.[4]
Surface area is important in chemical kinetics. Increasing the surface area of a substance generally increases the rate of a chemical reaction. For example, iron in a fine powder will combust, while in solid blocks it is stable enough to use in structures. For different applications a minimal or maximal surface area may be desired.
The surface area of an organism is important in several considerations, such as regulation of body temperature and digestion. Animals use their teeth to grind food down into smaller particles, increasing the surface area available for digestion. The epithelial tissue lining the digestive tract contains microvilli, greatly increasing the area available for absorption. Elephants have large ears, allowing them to regulate their own body temperature. In other instances, animals will need to minimize surface area; for example, people will fold their arms over their chest when cold to minimize heat loss.
The surface area to volume ratio (SA:V) of a cell imposes upper limits on size, as the volume increases much faster than does the surface area, thus limiting the rate at which substances diffuse from the interior across the cell membrane to interstitial spaces or to other cells. Indeed, representing a cell as an idealized sphere of radius r, the volume and surface area are, respectively, V = (4/3)r3 and SA = 4r2. The resulting surface area to volume ratio is therefore 3/r. Thus, if a cell has a radius of 1 m, the SA:V ratio is 3; whereas if the radius of the cell is instead 10 m, then the SA:V ratio becomes 0.3. With a cell radius of 100, SA:V ratio is 0.03. Thus, the surface area falls off steeply with increasing volume.
BET theory, technique for the measurement of the specific surface area of materials
^ "Archived copy" (PDF). Archived from the original (PDF) on 2011-12-15. Retrieved 2012-07-24.CS1 maint: archived copy as title (link)
^ Rorres, Chris. "Tomb of Archimedes: Sources". Courant Institute of Mathematical Sciences. Archived from the original on 2006-12-09. Retrieved 2007-01-02.
Within the context of the built environment, the term structure refers to anything that is constructed or built from interrelated parts with a fixed location on the ground. This includes buildings, but can refer to any body that is designed to bear loads, even if it is not intended to be occupied by people (engineers sometimes refer to these as 'non-building' structures such as bridges, tunnels, and so on).
In terms of geography and the built environment, the term location is used to refer to a point or area on the Earths surface. It is commonly used to imply more geometrical certainty than place which tends to be used to indicate somewhere with a boundary that can be ambiguous. It also differs to space, which is more abstract and tends to be used to refer to a location without human value or meaning having been attached to it.
Location can be defined in a number of ways:
Relative location: Described as displaced from another point, e.g. 10 miles south of [place].
Locality: An area, usually highly populated, that has an ambiguous boundary, e.g. Greater London.
Absolute location: Uses a Cartesian coordinate grid (e.g. the World Geodetic System) to plot latitudes and longitudes.
In terms of property development and real estate, the common mantra is location, location, location, which is used to emphasise the importance and centrality of location. This mantra refers to the fact that, typically, similar buildings (e.g. houses) can increase or decrease in value depending on their location, and that while structures can be improved, renovated, decorated, and so on, or its use class changed, its location cannot be changed.
However, in certain circumstances a structure can be moved from one place to another, in a process known as relocation. This can be done either by disassembling the structure and reassembling it in a new position, or by transporting it in its entirety. This is, though, a complex process and is often prohibitively expensive. For more information, see Structure relocation.
Thermal conductivity (sometimes referred to as k-value or lambda value ()) is a measure of the rate at which temperature differences transmit through a material. The lower the thermal conductivity of a material, the slower the rate at which temperature differences transmit through it, and so the more effective it is as an insulator. Very broadly, the lower the thermal conductivity of a building's fabric, the less energy is required to maintain comfortable conditions inside.
Thermal conductivity is a fundamental material property independent of thickness. It is measured watts per meter kelvin (W/mK).
The thermal resistance of the layers of the a building's fabric (R measured in in mK/W) can be calculated from the thickness of each layer / the thermal conductivity of that layer.
The U value of an element of a building can be calculated from sum of the thermal resistances (R-values) of the layers that make up the element plus its internal and external surface resistances (Ri and Ro).
U-value = 1 / (R + Ri + Ro)
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a buildings fabric are as insulators.
The standards for the measurement of thermal conductivity are BS EN 12664, BS EN 12667 and BS EN 12939. In the absence of values provided by product manufacturers following thermal conductivity tests, the thermal conductivity data obtained from BS EN 12524 Building materials and products. Hygrothermal properties.
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines the perimeter of a building as:'The maximum aggregate plan perimeter, found by vertical projection onto a horizontal plane. (See Section 15 of Approved Document B Volume 2.)'
The term cost in the construction industry generally refers to the amount that has to (or will have to) be paid to receive goods or services. It may also have wider interpretations, such as the environmental cost or the social cost of a particular purchase or action, lifecycle costs (rather than capital costs), and so on.
Generally cost is not fixed. There is uncertainty at the beginning of a project about precisely what is required, and whilst this is clarified as the project proceeds and more decisions are made, even when a firm price has been accepted from suppliers, this is likely to change as a result of variations to requirements, events such as exceptionally adverse weather (relevant events), the rate of inflation (fluctuations), and so on.
Skirting boards, also known as baseboards, are boards that run around the lowest part of an interior wall. Typically, they cover the joint between the floor and the wall surface.
They can be used for purely decorative purposes and can feature mouldings and intricate chip carpentry. However, they are more commonly to be a simple plank of timber that has been fixed (with nails, screws, glue, and so on), to the wall.
A more functional purpose of skirting boards is to act as protection for the wall from abrasion, accidental knocks from furniture, wear and tear, and so on. They can also be used to hide unsightly wall or floor edges which may be uneven and untidy.
The most common material that is used for skirting boards is timber, which can be left untreated or lacquered, painted, etc. Plastics such as uPVC can also be used and is often glued in place to the wall. Vinyl can also be used and can be a particularly durable option.
Skirting boards can often have wires running along the top of them with clips attaching them at spaced intervals.
For more information, see How to fit skirting boards, and Types of skirting board.
Density of construction materials are its mass per unit volume of materials. It is expressed in kg/m3 or lb/ft3 and shows compactness of building material. Density is also called as unit weight of substance. It is represented by symbol called row (p). Density represents the degree of compactness of material. If the material is of more density, it is more compacted material.
Embodied carbon is the total greenhouse gas (GHG) emissions (often simplified to carbon) generated to produce a built asset. This includes emissions caused by extraction, manufacture/processing, transportation and assembly of every product and element in an asset. In some cases, (depending on the boundary of an assessment), it may also include the maintenance, replacement, deconstruction, disposal and end-of-life aspects of the materials and systems that make up the asset. It excludes operational emissions of the asset.
Collision Detection - Use this function to identify collisions among 3D elements in the model. A collision occurs when two or more elements physically intersect.
Collision Detection works by checking for collisions between any two groups of elements. The groups are defined by criteria chosen by you.
For example, you might run Collision Detection:
Between construction and MEP elements. (MEP elements can come from hotlinked or merged external MEP IFC files, or else modeled inside ARCHICAD.)
Between concrete and steel construction elements - Between elements classified as different product/element types (by Uniclass, OmniClass, UniFormat or any other classification system)
Between elements classified as different product/element types (by Uniclass, OmniClass, UniFormat or any other classification system)
To check the headroom clearance for escape routes or access for the disabled
Collision Detection is available from the Floor Plan and 3D windows only.
Topics in this section: - Understanding Collisions
Understanding Collisions - Run Collision Detection
Run Collision Detection - Define Collision Groups
Define Collision Groups - Set Volume/Surface Tolerances
Set Volume/Surface Tolerances - Exempt Building Material from Collision Detection
Exempt Building Material from Collision Detection - Example: Headroom Collision Check
Example: Headroom Collision Check - Understanding Collisions
Understanding Collisions - Only elements on visible Layers are considered
Only elements on visible Layers are considered - Elements that are just touching do not count as colliding elements
Elements that are just touching do not count as colliding elements
Priority-Based Connections do not cause collisions - Solid Element Operations and Priority-Based Connections are already resolved in the model and do not cause collisions
Solid Element Operations and Priority-Based Connections are already resolved in the model and do not cause collisions
3D Cutting Planes are ignored (the entire model is considered regardless of Cutting Planes)
You can define Tolerances for colliding Volumes and/or surfaces: if the colliding volume/surface area does not exceed the defined Tolerance value, it does not count as a collision.
See Set Volume/Surface Tolerances. - The status of Building Materials (Participates in Collision Detection property) is considered
The status of Building Materials (Participates in Collision Detection property) is considered
See Exempt Building Material from Collision Detection. - Run Collision Detection
Run Collision Detection - 1.Go to the Floor Plan or 3D Window.
1.Go to the Floor Plan or 3D Window.
2.Go to Design > Collision Detection. - 3.In the dialog box, define criteria for the two groups of 3D elements that you want to check.
3.In the dialog box, define criteria for the two groups of 3D elements that you want to check.
If any elements are selected, Collision Detection will check only selected elements! See the top of the dialog for feedback on any current selection.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionDetection1.png https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionSelected.png - See Define Collision Groups for more information.
See Define Collision Groups for more information. - 4.Set Surface and/or Volume Tolerance values as needed.
4.Set Surface and/or Volume Tolerance values as needed.
See Set Volume/Surface Tolerances for more information.
5.Press Check to run Collision Detection. - 6.View the Collision Detection Report:
6.View the Collision Detection Report: - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionReport.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionReport.png - If there are collisions:
If there are collisions: - 7.Click Continue to open the Markup Tools Palette, if it is not open already.
7.Click Continue to open the Markup Tools Palette, if it is not open already.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/ClashesinMarkup.png - Each collision is named by default: Clash plus a number.
Each collision is named by default: Clash plus a number.
Collisions are automatically assigned the Markup Style entitled Collision. If such a style does not exist in the project, it is created automatically.
See Markup Styles Dialog Box. - Use the Markup function to highlight and zoom to the Collisions, make edits or add Markup notes as needed. Once you correct a collision, you should delete it from the list of Markup Entries.
Use the Markup function to highlight and zoom to the Collisions, make edits or add Markup notes as needed. Once you correct a collision, you should delete it from the list of Markup Entries.
See Project Markup. - Define Collision Groups
Define Collision Groups - To check collisions between all element types, use the same criteria for both groups.
To check collisions between all element types, use the same criteria for both groups.
To check collisions between 3D elements and MEP elements only, limit one of the groups to elements classified as MEP.
Click Add to bring up a dialog to choose any Properties and Parameters by which to limit the group.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/AddParameters.png - To use a saved Find & Select criteria set to define a Collision Group: click the arrow on the Add button to list the projects criteria sets:
To use a saved Find & Select criteria set to define a Collision Group: click the arrow on the Add button to list the projects criteria sets:
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CriteriaSetsCollision.png - If you pick a Criteria Set here, its contents will overwrite the Groups current criteria.
If you pick a Criteria Set here, its contents will overwrite the Groups current criteria.
Listed Criteria Sets may be disabled if the set includes criteria not applicable to Collision Detection (e.g. 2D element types, or IFC properties.)
See also Predefined Criteria Sets. - Set Volume/Surface Tolerances
Set Volume/Surface Tolerances - Optionally, define Tolerances for the volume and surface of elements colliding parts.
Optionally, define Tolerances for the volume and surface of elements colliding parts.
Elements are considered to collide if the colliding parts volume or (if enabled) the colliding parts surface area exceeds the Tolerance value.
Note: The units here are those of the projects Working Units (Options > Project Preferences).
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/TolerancesSurface.png - Volume Tolerance
Volume Tolerance - Collision Detection always considers colliding elements in terms of the volume of the colliding parts.
Collision Detection always considers colliding elements in terms of the volume of the colliding parts.
You can set an optional Volume Tolerance: If the volume of the two elements colliding parts exceeds this tolerance value, the elements are treated as colliding.
Check for Surface Collision - As an additional option, the Collision Detection function also checks the surface area of the colliding parts. If you enable Surface check and set a tolerance, then elements are treated as colliding if the colliding surface area exceeds this Surface Tolerance value.
As an additional option, the Collision Detection function also checks the surface area of the colliding parts. If you enable Surface check and set a tolerance, then elements are treated as colliding if the colliding surface area exceeds this Surface Tolerance value.
Note: If Surface Check is on, it is possible that two elements will be considered as colliding even if the colliding volume doesnt exceed the Volume Tolerance - because the colliding surface area exceeds the Surface Tolerance. See the example below.
Example: Collision Detection with Volume/Surface Tolerances
Run Collision Detection with the Tolerance settings shown here.
The following two cubes are one cubic meter each. They collide slightly; the overlapping volume is very slight (it doesnt exceed Volume Tolerance), but the overlapping surface is considerable (it exceeds Surface Tolerance). As a result: Collision Detection counts these two elements as colliding.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollidingSurfaceArea.png - Two Colliding Elements (based on Surface Area of Colliding Part)
Two Colliding Elements (based on Surface Area of Colliding Part)
Example: Headroom Collision Check - We will check for Headroom collision in this 3D view of the model.
We will check for Headroom collision in this 3D view of the model.
Note: The headroom visibility is turned on at Document > Model View > Model View Options (Stair Options).
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/Headroom3D.png - 1.Go to Design > Collision Detection.
1.Go to Design > Collision Detection. - 2.In the dialog box, define the collision criteria.
2.In the dialog box, define the collision criteria.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/HeadroomCollisionDialog.png - For Group 1: all 3D elements
For Group 1: all 3D elements - For Group 2: Stairs, considering the Headroom part of the Stair Model.
For Group 2: Stairs, considering the Headroom part of the Stair Model.
3.Press Check to run Collision Detection. - 4.View the Collision Detection Report: One collision is found.
4.View the Collision Detection Report: One collision is found.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionReportHeadroom.png - 5.Click Continue to open the Markup Palette to see the clash and zoom to it in the model.
5.Click Continue to open the Markup Palette to see the clash and zoom to it in the model.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/080_collaboration/CollisionDone.png - Exempt Building Material from Collision Detection
Exempt Building Material from Collision Detection - Collision Detection takes the elements Building Materials into account. Building Materials can be set to participate in Collision Detection, using the checkbox Participates in Collision Detection in the Classification and Properties panel of Building Materials, at Options > Attributes > Building Materials.
Collision Detection takes the elements Building Materials into account. Building Materials can be set to participate in Collision Detection, using the checkbox Participates in Collision Detection in the Classification and Properties panel of Building Materials, at Options > Attributes > Building Materials.
If this checkbox is turned off, then the Building Material will not participate in Collision Detection.
Gross area is the total area enclosed by the walls. Net area is the usable area. While the difference between gross and net area depends on the building and the region, net area typically excludes the following spaces from the gross area.
Click to see full answer. - People also ask, what does net area mean?
People also ask, what does net area mean?
NET AREA is the area required for specific uses such as; classrooms, laboratories, offices, conference rooms, auditoriums, dining rooms, storage rooms, shops and other functional spaces. Net area is measured to the interior face of enclosing walls.
Secondly, how do you calculate gross area? Calculate the area of each square or rectangle by multiplying the length by height. Add up the area of each square or rectangle to obtain the total gross area.
Regarding this, what does gross floor area mean?
Gross floor area (GFA) in real estate is the total floor area inside the building envelope, including the external walls, and excluding the roof. Definitions of GFA, including which areas are to be counted towards it and which areas aren't, vary around the world.
How do you calculate gross leasable area? - This is the floor area that can be used by tenants. This includes the the common areas of the building. So if the net leasable space is 11,500 square feet, the gross leasable area is the area adding back the common area square footage of 3,500 square feet.
This is the floor area that can be used by tenants. This includes the the common areas of the building. So if the net leasable space is 11,500 square feet, the gross leasable area is the area adding back the common area square footage of 3,500 square feet.
ROOM_NAME String Zone name - ROOM_NUMBER String room number - Zone number
ROOM_NUMBER String room number - Zone number - ROOM_AREA Area of gross/net polygon
ROOM_AREA Real Area of gross/net polygon
ROOM_PERIM Perimeter of gross/net polygon
ROOM_HOLES_PRM Perimeter of net polygon holes - ROOM_WALLS_PRM Length 0.0 Perimeter of net polygon (with holes) but only where bordered by wall
ROOM_WALLS_PRM Perimeter of net polygon (with holes) but only where bordered by wall
ROOM_CORNERS Corners of net polygon (with holes)
ROOM_CONCAVES Concave corners of net polygon (with holes)
ROOM_WALLS_SURF wall surface - Bordering walls surfaces (bordering parts)
ROOM_DOORS_WID Doors lengths at border - ROOM_DOORS_SURF Real 0.0 Doors surfaces at border
ROOM_DOORS_SURF Doors surfaces at border - ROOM_WINDS_WID Length 0.0 Windows lengths at border
ROOM_WINDS_WID Windows lengths at border - ROOM_WINDS_SURF Real 0.0 Windows surfaces at border
ROOM_WINDS_SURF Windows surfaces at border - ROOM_BASELEV Length 0.0 Zone level
ROOM_BASELEV Zone level - ROOM_FL_THICK Length 0.0 Zone subfloor thickness
ROOM_FL_THICK Zone subfloor thickness - ROOM_HEIGHT Length 0.0 Zone height
ROOM_HEIGHT Zone height - ROOM_NET_AREA Real 0.0 Area of net polygon (with holes)
ROOM_NET_AREA Area of net polygon (with holes)
ROOM_NET_PERIMETER Perimeter of net polygon (with holes)
ROOM_WALL_EXTR_AREA Reducing area by walls inside zone (not zone boundary type!)
ROOM_COLUMN_EXTR_AREA Reducing area by columns inside zone (not zone boundary type!)
ROOM_FILL_EXTR_AREA Reducing area by hatches inside zone (considering percentage!)
ROOM_LOW_EXTR_AREA Reducing area by low parts (trimmed) (considering preferences!)
ROOM_TOTAL_EXTR_AREA 0.0 Sum of previous values (total extraction)
ROOM_REDUCED_AREA ROOM_NET_AREA ROOM_TOTAL_EXTR_AREA - ROOM_AREA_FACTOR Real 0.0 1 Reduced_by_in_dialog / 100
ROOM_AREA_FACTOR Reduced_by_in_dialog / 100 - ROOM_CALC_AREA Real 0.0 ROOM_REDUCED_AREA * ROOM_AREA_FACTOR
ROOM_CALC_AREA ROOM_REDUCED_AREA * ROOM_AREA_FACTOR - ROOM_VOLUME Real 0.0 Calculated from trimmed room upon net polygon
ROOM_VOLUME Calculated from trimmed room upon net polygon
ROOM_BOUNDARY_SURF Surface of boundary side pages - ROOM_TOP_SURFACE Real 0.0 Surface of zone top
ROOM_TOP_SURFACE Surface of zone top - ROOM_BOT_SURFACE Real 0.0 Surface of zone bottom
ROOM_BOT_SURFACE Surface of zone bottom - ROOM_ROOF_TOP_SURF Real 0.0 Surface of zone top where trimmed by a Roof
ROOM_ROOF_TOP_SURF Surface of zone top where trimmed by a Roof
ROOM_ROOF_BOT_SURF Surface of zone bottom where trimmed by a Roof
ROOM_SLAB_TOP_SURF Surface of zone top where trimmed by a Slab
ROOM_SLAB_BOT_SURF Surface of zone bottom where trimmed by a Slab
ROOM_BEAM_TOP_SURF Surface of zone top where trimmed by a Beam
ROOM_BEAM_BOT_SURF Surface of zone bottom where trimmed by a Beam
ROOM_WALL_IN_TOP_SURF Real Sum of top surfaces of wall insets (or recess or niche)
ROOM_WALL_IN_BACK_SURF Sum of back surfaces of wall insets (facing to window)
ROOM_WALL_IN_SIDE_SURF Sum of side surfaces of wall insets
ROOM_POLY_STATUS Integer 0 0:manual, 1:Auto, 2:Auto-refline
Humidity refers to the concentration of water vapor in the air. The level of humidity in your home can influence many aspects of your personal health. Studies have found both excessively high humidity1 and excessively low humidity2 can be problematic, albeit for different reasons.
Humidity can also affect sleep. Studies have found that high humidity3 can interfere with your sleep cycle and important processes that occur during crucial sleep stages. Additionally, humid climates are associated with higher concentrations of allergens4 that trigger adverse reactions and disrupt sleep for some people. Maintaining healthy humidity levels in your home can make sleeping in your bedroom much more comfortable.
Luminous intensity, the quantity of visible light that is emitted in unit time per unit solid angle. The unit for the quantity of light flowing from a source in any one second (the luminous power, or luminous flux) is called the lumen. The lumen is evaluated with reference to visual sensation. The sensitivity of the human eye is greatest for light having a wavelength of 555 nanometres (10-9 metre); at this wavelength there are 685 lumens per watt of radiant power, or radiant flux (the luminous efficiency), whereas at other wavelengths the luminous efficiency is less. The unit of luminous intensity is one lumen per steradian, which is the unit of solid anglethere are 4 steradians about a point enclosed by a spherical surface. This unit of luminous intensity is also called the standard candle, or candela, one lumen per steradian.
door opening, opening size - The size of the doorframe opening measured from jamb to jamb and from floor line or threshold to head of frame; usually equal to the actual door size plus clearances.
The size of the doorframe opening measured from jamb to jamb and from floor line or threshold to head of frame; usually equal to the actual door size plus clearances.
A door profile refers to the joint where the sticking and panel come together. Think of profiles as the icing on the cake. You can achieve distinct looks by selecting different sticking and panel styles. With 66 combinations of sticking and panel styles to choose from, we are confident youll find the perfect profile for your project. If not, we will be happy to partner with your dealer to create a custom solution.
Rails are the horizontal pieces of the door. Rails are important to consider for hardware mounted to the top of bottom of the door. Door hardware such as concealed or surface mounted closers as well as kick plates or armor plates must have enough room to be installed inside of or on the surface of the rails of the door. If the hardware requires a mortise in the top or bottom of the door be sure that the dimension of the rails will allow for it without compromising the structural integrity of the door. Generally a rail is a minimum 1-1/8 wide or can be as wide as 5, depending on the application.
Louvers (door vents) can be added to virtually any commercial steel or wood door. Louvers provide air ventilation between rooms or inside of closets. Louvered doors help ventilate rooms when closed while still providing privacy and security. Louvers are often found inside of restroom and electrical or mechanical closet doors. Call us for pricing on special louver types, sizes, finishes and volume discounts.
The masonry arch, one of mans oldest architectural forms, is defined as a rigid span curving upward between two points of support. The arch appears in a wide variety of structures ranging from the purely decorative triumphal arch to the masonry arch bridge where it sustains great loads.
The round arch, Figure 1, was used by the early Chinese in all types of buildings. In ancient Egypt, this arch and others were used in nonceremonial structures such as engineering works and private dwellings. The Babylonians, on the other hand, used their arches in temples, palaces, and tombs. The Romans used the arch freely in their secular structures, as in the Colosseum, and in their engineering works like the aqueduct, but in their temples they followed the Greek style with the horizontal entablature.
Many forms of the arch have been developed during the centuries of its use, ranging from the flat or jack arch through the segmental, circular, parabolic to the pointed Gothic. Used freely in the great cathedrals of Europe, the Gothic or pointed arch had a structural use more important than the ornamental effect, as it minimized the outward thrust, making possible the firmness and stability combined with the lofty and spacious interior characteristic of the Gothic cathedral.
Two distinct types of arches have been recognized based on span, rise, and loading. The more common concrete masonry arch is the minor arch where maximum span is limited to about 6 feet (1.8 m) with a rise-to-span ratio not exceeding 0.15, and carrying loads up to 1500 lb per foot of span (21,891 N/m). The second type of arch is the major arch where span, rise, and loading may exceed those of the minor. Illustrations of both types of arches are shown in Figure 1. However, the design section of this TEK discusses only minor arches.
Window Grilles are decorative pattern on a window or door consisting of horizontal and/or vertical bars that divide the larger sheet of glass into smaller panes. Grille types include simulated divided lites (SDL), true divided lites (TDL), grilles in the airspace (GIA), and wood removable grilles.
Are Window Grilles Important? - When windows were first developed, glass could not be created in large sheets like it is today. It was too fragile and large pieces were impossible to move without breaking. The solution was to create many small pieces of glass joined together by window grilles.
When windows were first developed, glass could not be created in large sheets like it is today. It was too fragile and large pieces were impossible to move without breaking. The solution was to create many small pieces of glass joined together by window grilles.
Today, we have the technology to create large seamless panes of glass, so window grilles are now a purely aesthetic consideration for consumers that prefer a traditional or even historically accurate window style.
Are Window Grilles In Style? - Window grilles remain a very popular style for homeowners todayespecially for homes with traditional styling. On many historical architectural styles, window grilles are almost a must. On Victorians, Cape Cods, or Colonials for example, the architectural styling of these types of houses was designed with divided lite windows. These houses may look a little off or naked without the window grilles they are commonly associated with.
Window grilles remain a very popular style for homeowners todayespecially for homes with traditional styling. On many historical architectural styles, window grilles are almost a must. On Victorians, Cape Cods, or Colonials for example, the architectural styling of these types of houses was designed with divided lite windows. These houses may look a little off or naked without the window grilles they are commonly associated with.
If you wantor in some cases due to HOA requirementsneed window grilles to match your homes architectural style, you should be certain that you choose a window replacement manufacturer that offers a variety of different grille combinations and styles. Window grilles were common across large areas of the country and thus have a number of varying styles depending on where you live.
Types of Window Grilles - At Weather Shield, we offer three types of window grilles, each with a variety of styles and design options:
At Weather Shield, we offer three types of window grilles, each with a variety of styles and design options:
Removable Wood Grille - Wood Removable Grilles feature a frame design that offers strength superior to stick grilles offered by other window manufacturers. The frame snaps securely into the interior sash using a concealed pin system. Wood Removable Grilles make window cleaning easier, yet provide an added interior dimension. Custom grille designs are available.
Wood Removable Grilles feature a frame design that offers strength superior to stick grilles offered by other window manufacturers. The frame snaps securely into the interior sash using a concealed pin system. Wood Removable Grilles make window cleaning easier, yet provide an added interior dimension. Custom grille designs are available.
Between the Glass Grille - Grille Between the Glass consist of aluminum muntin bars in between two panes of insulating glass, giving you the look of divided lites while making window cleaning easier.
Grille Between the Glass consist of aluminum muntin bars in between two panes of insulating glass, giving you the look of divided lites while making window cleaning easier.
Simulated Divided Lite - Simulated Divided Lites (SDL) offer the authentic look of True Divided Lites without sacrificing energy efficiency. Interior and exterior bars are permanently adhered to the glass and a narrow spacer bar is positioned within the insulating glass airspace. Unlike True Divided Lites, SDL utilizes a single pane of insulating glass, decreasing the potential for energy loss. Exterior bars will be finished to match the exterior finish specified
Simulated Divided Lites (SDL) offer the authentic look of True Divided Lites without sacrificing energy efficiency. Interior and exterior bars are permanently adhered to the glass and a narrow spacer bar is positioned within the insulating glass airspace. Unlike True Divided Lites, SDL utilizes a single pane of insulating glass, decreasing the potential for energy loss. Exterior bars will be finished to match the exterior finish specified
Sill nosing is used to cover concrete or wood sub-sill.
It provides an attractive finished look to new and old door openings, covering defects in sub-sill.
These stops will affect the pivot hole location of an assembly.
Sill nosing is held in place with mastic and pressure from threshold placement.
Ratings - Fire Rated - UL10C - Positive Pressure
Fire Rated - UL10C - Positive Pressure - Underwriters Laboratory 4L10
Underwriters Laboratory 4L10 - louver - A framed opening, as in a wall, door, or window, fitted with fixed or movable horizontal slats for admitting air or light and often for shedding rain. b. One of the slats used in such an opening. Width.
louver - A framed opening, as in a wall, door, or window, fitted with fixed or movable horizontal slats for admitting air or light and often for shedding rain. b. One of the slats used in such an opening. Width.
Parts of a Shutter Panel - Stile. The Shutter stiles are the upright, vertical sections of solid wood. The shutter louvers rotate between the shutter stiles.
Stile. The Shutter stiles are the upright, vertical sections of solid wood. The shutter louvers rotate between the shutter stiles.
Top Rail. Horizontal bar at the top of a shutter panel gives its form, structure and stability (with a notch for the tilt bar).
Bottom Rail. Horizontal bar at the bottom of a shutter panel provides form, structure and stability.
Push Rod/Tilt Bar. The tilt rod is the horizontal piece of wood or metal which links the shutters louvers together and allows all louvers linked by that particular rod to open and close in unison.
Slats/ Louver. Movable horizontal pieces of wood which form the major part of the shutter panel.
Hanging Hinge. A hinge that connects a shutter panel to the window jamb or hanging strip.
Mid Rail. A horizontal bar that creates top and bottom louver sections.
Mouse Hole. A small indentation on the top and bottom rails where the tilt rod rests
Other Shutter Terms - Cafe Type. A shutter unit that only covers the lower portion of a window.
Cafe Type. A shutter unit that only covers the lower portion of a window.
Double Tier. A shutter unit that has one set of shutters on the top and one on the bottom. Each set of shutters opens independently of the other.
Frame. Used for mounting full height shutter units to the outside of a window opening
Panel. A single shutter. Most shutter units consist of more than one shutter panel.
Shutter Unit. Shutter panels and components that work together to cover a window opening.
Single Tier. A shutter unit that has one set of shutters from top to bottom. A single tier shutter may contain a divider rail, or may be a cafe type shutter unit that covers only the lower portion of a window.
Tilt Bar/Push Rod. The vertical bar used for adjusting the louver position.
Window Jamb. Your window opening verticle sides. This area is used to attach a shutter unit using mountings.
BEAM FIELD - DESCRIPTION
DESCRIPTION - Beam Cross Section
Beam Cross Section - Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Beam_CrossSection.png - Building Material/Composite/Profile
Building Material/Composite/Profile - Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Beam_CutFillType.png - Height
Height - Height of the Beam (difference between its base elevation and its top elevation)
Height of the Beam (difference between its base elevation and its top elevation)
Beam_Height.png - Hole Height
Hole Height - Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Beam_HoleHeight.png - Hole Level
Hole Level - Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Beam_HoleLevel.png - Hole Number
Hole Number - Total number of holes in the Beam.
Total number of holes in the Beam. - Beam_HoleNumber.png
Beam_HoleNumber.png - Hole Width
Hole Width - Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Beam_HoleWidth.png - Holes Surface Area
Holes Surface Area - Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Beam_HolesSurface.png - Holes Volume
Holes Volume - Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Beam_HolesVolume.png - Length Left
Length Left - Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthLeft.png - Length Right
Length Right - Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthRight.png - Bottom surface
Bottom surface - Name of the surface assigned to the bottom surface of the Beam.
Name of the surface assigned to the bottom surface of the Beam.
Beam_BottomMaterial.png - Left side surface
Left side surface - Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftMaterial.png - Right side surface
Right side surface - Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightMaterial.png - End surface
End surface - Name of the surface assigned to the two end surfaces of the Beam.
Name of the surface assigned to the two end surfaces of the Beam.
Beam_EndMaterial.png - Top surface
Top surface - Name of the surface assigned to the top surface of the Beam.
Name of the surface assigned to the top surface of the Beam.
Beam_TopMaterial.png - Offset
Offset - Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Beam_Offset.png - Slant Angle
Slant Angle - Angle of an inclined Beam
Angle of an inclined Beam - Beam_SlantAngle.png
Beam_SlantAngle.png - Bottom Surface Area
Bottom Surface Area - Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Beam_BottomSurface.png - Left side surface area
Left side surface area - Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftSurface.png - Right side surface area
Right side surface area - Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightSurface.png - End Surface Area
End Surface Area - Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Beam_EndSurface.png - Top Surface Area
Top Surface Area - Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Beam_TopSurface.png - Volume
Volume - Volume of the Beam, reduced by any SEOs or holes.
Volume of the Beam, reduced by any SEOs or holes.
Beam_Volume.png - Conditional Volume
Conditional Volume - Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Takes SEOs into account. - Beam_ConditionalVolume.png
Beam_ConditionalVolume.png - Width
Width - Width of the Beam as entered in Info Box or Beam Tool Settings
Width of the Beam as entered in Info Box or Beam Tool Settings
Beam_Width.png - General Listing Parameters
General Listing Parameters - Parameter
Parameter - Short Description
Short Description - Long Description
Long Description - 3D Length
3D Length - Length of construction element, as projected from its Reference Line.
Length of construction element, as projected from its Reference Line.
3D Back View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
For CW components: Back = inside of the Curtain Wall
3D Front View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
For CW components: Front = outside of the Curtain Wall
3D Left Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the element viewed from its left side.
3D Right Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the element viewed from its right side
3D Perimeter - Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Relevant for Roof, Shell, CW Panel - 3D Holes Perimeter
3D Holes Perimeter - Total Perimeter of all the holes in the Mesh. Does not take SEOs into account.
Total Perimeter of all the holes in the Mesh. Does not take SEOs into account.
Relevant for Roof or Shell. - 2D Cross Section Preview
2D Cross Section Preview - 2D Plan Preview
2D Plan Preview - 3D Axonometry
3D Axonometry - Absolute Top Link Story
Absolute Top Link Story - Name of the elements top-linked story.
Name of the elements top-linked story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: 1. Story - ARCHICAD IFC ID
ARCHICAD IFC ID - The Globalid IFC attribute automatically assigned by ARCHICAD to each element
The Globalid IFC attribute automatically assigned by ARCHICAD to each element
Area - Generally: a construction element's top surface area, net of any holes.
Generally: a construction element's top surface area, net of any holes.
Building Material/Composite/Profile/Fill - Name of the elements Building Material, or its composite structure, or its profile, or its fill
Name of the elements Building Material, or its composite structure, or its profile, or its fill
Building Materials (All) - Lists all of the elements Building Materials in a single Schedule cell
Lists all of the elements Building Materials in a single Schedule cell
Cover Fill - Name of the Cover Fill assigned to the element (if any).
Name of the Cover Fill assigned to the element (if any).
Cover Fills are available for Zone, Mesh, Slab, Roof
Conditional Volume - Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
This volume may be conditioned on a defined Calculation Rule.
Condition: subtracts the volume of any openings that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce element volume by).
Reduced by trims and SEOs. - Element ID
Element ID - Lists Element ID.
Lists Element ID. - For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
Elevation to 1st/2nd Reference Level - Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Elevation levels are defined at Options > Project Preferences > Reference Levels
Elevation to Linked/Home Story - Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Relevant for Doors/Windows. Value is the opening's elevation from its linked (anchor) story to its sill height.
Elevation to Project Zero - Element's absolute elevation, measured from zero.
Element's absolute elevation, measured from zero. - Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels
Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels
Elevation to Sea Level - Element's elevation relative to Sea Level (Altitude of the Project Location).
Element's elevation relative to Sea Level (Altitude of the Project Location).
Define Sea Level value (Altitude) at Options > Project Preferences > Project Location.
External IFC ID - The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
Floor Plan Perimeter - Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Relevant for Wall, Slab, Mesh, Morph
For Wall: Perimeter can vary depending on its Floor Plan Projection settings (e.g. Cut Only vs. Projected with Overhead)
Wall intersections have no effect on the perimeter value.
Floor Plan Holes Perimeter - Total Perimeter of all the holes in the element.
Total Perimeter of all the holes in the element.
Relevant for Slab, Mesh, Zone - From Zone Number
From Zone Number - Number of the Zone from which the element opens.
Number of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Number of the Zone (if any) from which the Panel faces outward. (The Zone that abuts the panels inside surface.)
To Zone Number - Number of the Zone toward which the element opens.
Number of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the Panels outside surface.
From Zone - Name of the Zone from which the element opens.
Name of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Zone (if any) from which the Panel faces outward. (The Zone that abuts the panels inside surface.)
To Zone - Name of the Zone toward which the element opens.
Name of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the panels outside surface.
Gross Volume - Wall: Includes Volume of Openings, doors and windows.
Wall: Includes Volume of Openings, doors and windows.
Column: Includes Volume of both Core and Veneer.
Roof/Shell/Slab: Includes the volume of any holes. Reduced by trims.
See also the Slab parameter: "Gross Volume of the Slab, Minus the Holes"
GDL Preview Picture - Preview picture, of GDL Object type elements only.
Preview picture, of GDL Object type elements only.
Height - D-W: Height of the window/door, as defined in the Height field of the openings Settings dialog box or Info Box.
D-W: Height of the window/door, as defined in the Height field of the openings Settings dialog box or Info Box.
Height of the panel, not including the panels extrusion into the surrounding frames.
CW: defined in Curtain Wall System Settings or the Info Box
CW Panel: Height of the panel, not including the panels extrusion into the surrounding frames.
Zone: Height of the Zone body measured from the Zones bottom elevation. Defined in the Name and Positioning Panel of Zone Settings.
Skylight: Height parameter in the Preview and Positioning Panel (or the Skylight Settings Panel)
Home Offset - Offset of element from its Home Story.
Offset of element from its Home Story. - For Door/Window: The sill height, measured from the host Wall's home story.
For Door/Window: The sill height, measured from the host Wall's home story.
Home Story (Obsolete) - Name of element's Home Story
Name of element's Home Story - As defined in Element settings.
As defined in Element settings. - Openings: Home Story depends on the opening's vertical position in the host element.
Openings: Home Story depends on the opening's vertical position in the host element.
Home Story Name - Name of element's Home Story
Name of element's Home Story - As defined in Element settings.
As defined in Element settings. - Openings: Home Story name depends on the opening's vertical position in the host element.
Openings: Home Story name depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Home Story Number - Number of element's Home Story
Number of element's Home Story - As defined in Element settings.
As defined in Element settings. - Door/Window: Home Story depends on the opening's vertical position in the host element.
Door/Window: Home Story depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Hotlink and Element ID - If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
Hotlink Master ID - If element is part of a Hotlink: Lists the Hotlink's Master ID only
If element is part of a Hotlink: Lists the Hotlink's Master ID only
IFC Assignment - Name of IFC Assignment (if any) to which element belongs.
Name of IFC Assignment (if any) to which element belongs.
IFC Assignment takes place in IFC Project Manager. Assignments include e.g. IFC Group, IFC Zone, IFC System.
IFC Type - Name of element's IFC Type
Name of element's IFC Type - Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel). IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel). IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
IFC Type Product - Lists name and type of element's IFC Type Product.
Lists name and type of element's IFC Type Product.
IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator. (IFC Translators dialog box)
Insulation Skin Thickness - Thickness of Wall, Roof, or Shell skins whose structure is defined as Insulation
Thickness of Wall, Roof, or Shell skins whose structure is defined as Insulation
Insulation Skin (Wall, Roof, Shell) is defined at Options > Project Preferences > Calculation Units & Rules.
Issue Date (of last Change) - Issue ID (of last Change)
Issue ID (of last Change) - Issue Name (of last Change)
Issue Name (of last Change) - Label Text
Label Text - Layer
Layer - Layer of element.
Layer of element. - Length
Length - Length of element.
Length of element. - Library Part Name
Library Part Name - Name, of GDL Object type elements only.
Name, of GDL Object type elements only.
Linked Changes - If element or sub-element is linked to a Change: lists the number of the linked Change(s)
If element or sub-element is linked to a Change: lists the number of the linked Change(s)
Locked - Element's locked/unlocked status
Element's locked/unlocked status - This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
Net Volume - Net volume of the element. Reduced by Solid Element Operations .
Net volume of the element. Reduced by Solid Element Operations .
Column: (including the volume of the core and of the veneer, if any).
Roof-Shell-Slab-Mesh: is reduced by the surface of any holes. Reduced by trims and SEOs.
Beam/Morph: reduced by holes and SEOs
Door-Window: Volume of the opening cut by the Door/Window. (Volume calculation based on hole that results from cutting the GDL openings out of the Wall.)
Parent ID - Element ID of he listed element's parent element
Element ID of he listed element's parent element - Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall)
Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall)
Position - Value of elements Position classification
Value of elements Position classification - Possible values: Interior, Exterior, Undefined
Possible values: Interior, Exterior, Undefined - Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Property Object Name - Name of property object (if any) linked to this element.
Name of property object (if any) linked to this element.
Property Objects can be linked to elements using the Listing panel of Element Settings. (This panel is hidden by default. Consult the Calculation Guide for details.)
Quantity - For a particular listed element, displays the number of scheduled elements.
For a particular listed element, displays the number of scheduled elements.
Related Zone Name - 2D - Name of the element's related Zone, if any.
Name of the element's related Zone, if any.
In general: the Zone which the element borders or intersects in 2D.
Related Zone definitions vary by element. See Description.
An element can have only one Related Zone. (If multiple Zones apply, the first create Zone is listed.)
(To identify the Zone(s) with which an element intersects in 3D, use the Related Zones- 3D parameter.)
Wall: The Zone which it borders, or the Zone which the Wall's 2D polygon intersects
Door/Window: Related Zone of the host Wall.
CW: The Zone which it (or at least one of its segments) borders
CW Frame/Panel: The Zone which its CW segment borders, and which the Frame/Panel touches.
CW Junction: All of the connecting subelements (at the Junction's gridpoint) border the Zone; or two of the connecting Frames (at the Junction's gridpoint) border the Zone
CW Accessory: The Zone bordered by the Accessory's parent Frame.
Shell/Roof: The Zone to which it connects via SEO, or by which it is cropped
Object, Light, Morph, Stair, Railing: The Zone that has the same Home Story as the element. For an Object: the centerpoint of its 3D bounding box is within the Zone polygon.
Beam: The Zone which the Beam's Reference line intersects in 2D. The Beam must be visible on this related Zone's home story.
Skylight: The Zone to which its parent Roof or Shell connects via SEO, or by which it is cropped.
Column: The Zone polygon intersected by any corner of the Column. The Column must be visible on this related Zone's home story.
Tread, Riser, Stair Structure: The related Zone of its parent Stair
Railing subelements: The related Zone of its parent Railing
Related Zone Number - 2D - Number of the element's related Zone in 2D, if any. See explanation for Related Zone Name - 2D, above.
Number of the element's related Zone in 2D, if any. See explanation for Related Zone Name - 2D, above.
Related Zone Name - 3D - Name of the Zone which the element intersects or borders in 3D, if any.
Name of the Zone which the element intersects or borders in 3D, if any.
Related Zone Number - 3D - Number of the element's related Zone in 3D, if any.
Number of the element's related Zone in 3D, if any.
Relative Top Link Story - Relative position of elements top-linked Story.
Relative position of elements top-linked Story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: Home + 1 - Slant Angle
Slant Angle - Angle of slanted or inclined element.
Angle of slanted or inclined element. - For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
Beam: Angle of an inclined Beam - CW Frame or Panel: Slant angle measured to the horizontal plane.
CW Frame or Panel: Slant angle measured to the horizontal plane.
Surface Area - Generally: the sum of all surfaces of an element.
Generally: the sum of all surfaces of an element.
Beam: The sum of all Beam surfaces (top, bottom, ends)
Column: Surface area of the Column's cross-section - Shell: Net surface area of the Reference Side
Shell: Net surface area of the Reference Side
Thickness - Element Thickness, as defined in Element Settings.
Element Thickness, as defined in Element Settings.
Width - Element Width parameter, as defined by its geometry or in Element Settings.
Element Width parameter, as defined by its geometry or in Element Settings.
Object: Width of the Object as defined in the Dimension 1 field of the Preview and Positioning Panel of Object Settings.
Column: Width of the column: Core Dimension 1 value, plus the width of any veneer.
BEAM FIELD - DESCRIPTION
DESCRIPTION - Beam Cross Section
Beam Cross Section - Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Beam_CrossSection.png - Building Material/Composite/Profile
Building Material/Composite/Profile - Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Beam_CutFillType.png - Height
Height - Height of the Beam (difference between its base elevation and its top elevation)
Height of the Beam (difference between its base elevation and its top elevation)
Beam_Height.png - Hole Height
Hole Height - Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Beam_HoleHeight.png - Hole Level
Hole Level - Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Beam_HoleLevel.png - Hole Number
Hole Number - Total number of holes in the Beam.
Total number of holes in the Beam. - Beam_HoleNumber.png
Beam_HoleNumber.png - Hole Width
Hole Width - Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Beam_HoleWidth.png - Holes Surface Area
Holes Surface Area - Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Beam_HolesSurface.png - Holes Volume
Holes Volume - Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Beam_HolesVolume.png - Length Left
Length Left - Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthLeft.png - Length Right
Length Right - Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthRight.png - Bottom surface
Bottom surface - Name of the surface assigned to the bottom surface of the Beam.
Name of the surface assigned to the bottom surface of the Beam.
Beam_BottomMaterial.png - Left side surface
Left side surface - Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftMaterial.png - Right side surface
Right side surface - Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightMaterial.png - End surface
End surface - Name of the surface assigned to the two end surfaces of the Beam.
Name of the surface assigned to the two end surfaces of the Beam.
Beam_EndMaterial.png - Top surface
Top surface - Name of the surface assigned to the top surface of the Beam.
Name of the surface assigned to the top surface of the Beam.
Beam_TopMaterial.png - Offset
Offset - Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Beam_Offset.png - Slant Angle
Slant Angle - Angle of an inclined Beam
Angle of an inclined Beam - Beam_SlantAngle.png
Beam_SlantAngle.png - Bottom Surface Area
Bottom Surface Area - Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Beam_BottomSurface.png - Left side surface area
Left side surface area - Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftSurface.png - Right side surface area
Right side surface area - Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightSurface.png - End Surface Area
End Surface Area - Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Beam_EndSurface.png - Top Surface Area
Top Surface Area - Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Beam_TopSurface.png - Volume
Volume - Volume of the Beam, reduced by any SEOs or holes.
Volume of the Beam, reduced by any SEOs or holes.
Beam_Volume.png - Conditional Volume
Conditional Volume - Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Takes SEOs into account. - Beam_ConditionalVolume.png
Beam_ConditionalVolume.png - Width
Width - Width of the Beam as entered in Info Box or Beam Tool Settings
Width of the Beam as entered in Info Box or Beam Tool Settings
Beam_Width.png - Default Going Depth
Default Going Depth - Going depth as defined in Stair Settings.
Going depth as defined in Stair Settings. - 350_default_going_depth.png
350_default_going_depth.png - Default Riser Height
Riser Height as defined in Stair Settings - 351_default_riser_height.png
351_default_riser_height.png - Default Riser Slant Angle
Default Riser Slant Angle - As defined in Stair Settings
As defined in Stair Settings - 352_default_riser_slant_angle.png
352_default_riser_slant_angle.png - Default Stair Width
Default Stair Width - Width of the Stair as defined in Stair Settings.
Width of the Stair as defined in Stair Settings.
353_deafult_stair_width.png - Front Surface Area
Front Surface Area - Total Surface area of the Stair from the front
Total Surface area of the Stair from the front
354_front_surface_area.png - Maximum Going (by Rule)
Maximum Going (by Rule) - As defined in Stair Settings (Rules & Standards Panel)
As defined in Stair Settings (Rules & Standards Panel)
355_maximum_going.png - Maximum Riser Height (by Rule)
Maximum Riser Height (by Rule) - As defined in Stair Settings (Rules & Standards Panel)
As defined in Stair Settings (Rules & Standards Panel)
356_maximum_riser.png - Minimum Going (by Rule)
Minimum Going (by Rule) - As defined in Stair Settings (Rules & Standards Panel)
As defined in Stair Settings (Rules & Standards Panel)
357_minimum_going.png - Minimum Riser Height (by Rule)
Minimum Riser Height (by Rule) - As defined in Stair Settings (Rules & Standards Panel)
As defined in Stair Settings (Rules & Standards Panel)
358_minimum_riser.png - Number of Risers (total)
Number of Risers (total) - 359_number_of_risers.png
359_number_of_risers.png - Number of Risers by Flights
Number of Risers by Flights - 360_number_of_risers_by_flight.png
360_number_of_risers_by_flight.png - Number of Treads (total)
Number of Treads (total) - 361_number_of_treads_total.png
361_number_of_treads_total.png - Number of Treads by Flights
Number of Treads by Flights - 362_number_of_treads_by_flight.png
362_number_of_treads_by_flight.png - Required Headroom Height
Stair Pitch - 365_stair_pitch.png
365_stair_pitch.png - Walking Line Length
Walking Line Length - Length of Calculated Walking Line.
Length of Calculated Walking Line. - Calculated Walking Line: defined in the Geometry and Positioning panel of Stair Settings.
Calculated Walking Line: defined in the Geometry and Positioning panel of Stair Settings.
(Can differ from length of graphically edited Walking Line.)
3D Length - Length of construction element, as projected from its Reference Line.
Length of construction element, as projected from its Reference Line.
3D Back View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
For CW components: Back = inside of the Curtain Wall
3D Front View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
For CW components: Front = outside of the Curtain Wall
3D Left Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the element viewed from its left side.
3D Right Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the element viewed from its right side
3D Perimeter - Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Relevant for Roof, Shell, CW Panel - 3D Holes Perimeter
3D Holes Perimeter - Total Perimeter of all the holes in the Mesh. Does not take SEOs into account.
Total Perimeter of all the holes in the Mesh. Does not take SEOs into account.
Relevant for Roof or Shell. - 2D Cross Section Preview
2D Cross Section Preview - 2D Plan Preview
2D Plan Preview - 3D Axonometry
3D Axonometry - Absolute Top Link Story
Absolute Top Link Story - Name of the elements top-linked story.
Name of the elements top-linked story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: 1. Story - ARCHICAD IFC ID
ARCHICAD IFC ID - The Globalid IFC attribute automatically assigned by ARCHICAD to each element
The Globalid IFC attribute automatically assigned by ARCHICAD to each element
Area - Generally: a construction element's top surface area, net of any holes.
Generally: a construction element's top surface area, net of any holes.
Building Material/Composite/Profile/Fill - Name of the elements Building Material, or its composite structure, or its profile, or its fill
Name of the elements Building Material, or its composite structure, or its profile, or its fill
Building Materials (All) - Lists all of the elements Building Materials in a single Schedule cell
Lists all of the elements Building Materials in a single Schedule cell
Cover Fill - Name of the Cover Fill assigned to the element (if any).
Name of the Cover Fill assigned to the element (if any).
Cover Fills are available for Zone, Mesh, Slab, Roof
Conditional Volume - Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
This volume may be conditioned on a defined Calculation Rule.
Condition: subtracts the volume of any openings that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce element volume by).
Reduced by trims and SEOs. - Element ID
Element ID - Lists Element ID.
Lists Element ID. - For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
Elevation to 1st/2nd Reference Level - Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Elevation levels are defined at Options > Project Preferences > Reference Levels
Elevation to Linked/Home Story - Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Relevant for Doors/Windows. Value is the opening's elevation from its linked (anchor) story to its sill height.
Elevation to Project Zero - Element's absolute elevation, measured from zero.
Element's absolute elevation, measured from zero. - Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels
Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels
Elevation to Sea Level - Element's elevation relative to Sea Level (Altitude of the Project Location).
Element's elevation relative to Sea Level (Altitude of the Project Location).
Define Sea Level value (Altitude) at Options > Project Preferences > Project Location.
External IFC ID - The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
Floor Plan Perimeter - Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Relevant for Wall, Slab, Mesh, Morph
For Wall: Perimeter can vary depending on its Floor Plan Projection settings (e.g. Cut Only vs. Projected with Overhead)
Wall intersections have no effect on the perimeter value.
Floor Plan Holes Perimeter - Total Perimeter of all the holes in the element.
Total Perimeter of all the holes in the element.
Relevant for Slab, Mesh, Zone - From Zone Number
From Zone Number - Number of the Zone from which the element opens.
Number of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Number of the Zone (if any) from which the Panel faces outward. (The Zone that abuts the panels inside surface.)
To Zone Number - Number of the Zone toward which the element opens.
Number of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the Panels outside surface.
From Zone - Name of the Zone from which the element opens.
Name of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Zone (if any) from which the Panel faces outward. (The Zone that abuts the panels inside surface.)
To Zone - Name of the Zone toward which the element opens.
Name of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the panels outside surface.
Gross Volume - Wall: Includes Volume of Openings, doors and windows.
Wall: Includes Volume of Openings, doors and windows.
Column: Includes Volume of both Core and Veneer.
Roof/Shell/Slab: Includes the volume of any holes. Reduced by trims.
See also the Slab parameter: "Gross Volume of the Slab, Minus the Holes"
GDL Preview Picture - Preview picture, of GDL Object type elements only.
Preview picture, of GDL Object type elements only.
Height - D-W: Height of the window/door, as defined in the Height field of the openings Settings dialog box or Info Box.
D-W: Height of the window/door, as defined in the Height field of the openings Settings dialog box or Info Box.
Height of the panel, not including the panels extrusion into the surrounding frames.
CW: defined in Curtain Wall System Settings or the Info Box
CW Panel: Height of the panel, not including the panels extrusion into the surrounding frames.
Zone: Height of the Zone body measured from the Zones bottom elevation. Defined in the Name and Positioning Panel of Zone Settings.
Skylight: Height parameter in the Preview and Positioning Panel (or the Skylight Settings Panel)
Home Offset - Offset of element from its Home Story.
Offset of element from its Home Story. - For Door/Window: The sill height, measured from the host Wall's home story.
For Door/Window: The sill height, measured from the host Wall's home story.
Home Story (Obsolete) - Name of element's Home Story
Name of element's Home Story - As defined in Element settings.
As defined in Element settings. - Openings: Home Story depends on the opening's vertical position in the host element.
Openings: Home Story depends on the opening's vertical position in the host element.
Home Story Name - Name of element's Home Story
Name of element's Home Story - As defined in Element settings.
As defined in Element settings. - Openings: Home Story name depends on the opening's vertical position in the host element.
Openings: Home Story name depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Home Story Number - Number of element's Home Story
Number of element's Home Story - As defined in Element settings.
As defined in Element settings. - Door/Window: Home Story depends on the opening's vertical position in the host element.
Door/Window: Home Story depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Hotlink and Element ID - If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
Hotlink Master ID - If element is part of a Hotlink: Lists the Hotlink's Master ID only
If element is part of a Hotlink: Lists the Hotlink's Master ID only
IFC Assignment - Name of IFC Assignment (if any) to which element belongs.
Name of IFC Assignment (if any) to which element belongs.
IFC Assignment takes place in IFC Project Manager. Assignments include e.g. IFC Group, IFC Zone, IFC System.
IFC Type - Name of element's IFC Type
Name of element's IFC Type - Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel). IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel). IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
IFC Type Product - Lists name and type of element's IFC Type Product.
Lists name and type of element's IFC Type Product.
IFC Type Mapping depends on "Type Mapping for Export" setting of the current Preview Translator. (IFC Translators dialog box)
Insulation Skin Thickness - Thickness of Wall, Roof, or Shell skins whose structure is defined as Insulation
Thickness of Wall, Roof, or Shell skins whose structure is defined as Insulation
Insulation Skin (Wall, Roof, Shell) is defined at Options > Project Preferences > Calculation Units & Rules.
Issue Date (of last Change) - Issue ID (of last Change)
Issue ID (of last Change) - Issue Name (of last Change)
Issue Name (of last Change) - Label Text
Label Text - Layer
Layer - Layer of element.
Layer of element. - Length
Length - Length of element.
Length of element. - Library Part Name
Library Part Name - Name, of GDL Object type elements only.
Name, of GDL Object type elements only.
Linked Changes - If element or sub-element is linked to a Change: lists the number of the linked Change(s)
If element or sub-element is linked to a Change: lists the number of the linked Change(s)
Locked - Element's locked/unlocked status
Element's locked/unlocked status - This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
Net Volume - Net volume of the element. Reduced by Solid Element Operations .
Net volume of the element. Reduced by Solid Element Operations .
Column: (including the volume of the core and of the veneer, if any).
Roof-Shell-Slab-Mesh: is reduced by the surface of any holes. Reduced by trims and SEOs.
Beam/Morph: reduced by holes and SEOs
Door-Window: Volume of the opening cut by the Door/Window. (Volume calculation based on hole that results from cutting the GDL openings out of the Wall.)
Parent ID - Element ID of he listed element's parent element
Element ID of he listed element's parent element - Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall)
Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall)
Position - Value of elements Position classification
Value of elements Position classification - Possible values: Interior, Exterior, Undefined
Possible values: Interior, Exterior, Undefined - Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Property Object Name - Name of property object (if any) linked to this element.
Name of property object (if any) linked to this element.
Property Objects can be linked to elements using the Listing panel of Element Settings. (This panel is hidden by default. Consult the Calculation Guide for details.)
Quantity - For a particular listed element, displays the number of scheduled elements.
For a particular listed element, displays the number of scheduled elements.
Related Zone Name - 2D - Name of the element's related Zone, if any.
Name of the element's related Zone, if any.
In general: the Zone which the element borders or intersects in 2D.
Related Zone definitions vary by element. See Description.
An element can have only one Related Zone. (If multiple Zones apply, the first create Zone is listed.)
(To identify the Zone(s) with which an element intersects in 3D, use the Related Zones- 3D parameter.)
Wall: The Zone which it borders, or the Zone which the Wall's 2D polygon intersects
Door/Window: Related Zone of the host Wall.
CW: The Zone which it (or at least one of its segments) borders
CW Frame/Panel: The Zone which its CW segment borders, and which the Frame/Panel touches.
CW Junction: All of the connecting subelements (at the Junction's gridpoint) border the Zone; or two of the connecting Frames (at the Junction's gridpoint) border the Zone
CW Accessory: The Zone bordered by the Accessory's parent Frame.
Shell/Roof: The Zone to which it connects via SEO, or by which it is cropped
Object, Light, Morph, Stair, Railing: The Zone that has the same Home Story as the element. For an Object: the centerpoint of its 3D bounding box is within the Zone polygon.
Beam: The Zone which the Beam's Reference line intersects in 2D. The Beam must be visible on this related Zone's home story.
Skylight: The Zone to which its parent Roof or Shell connects via SEO, or by which it is cropped.
Column: The Zone polygon intersected by any corner of the Column. The Column must be visible on this related Zone's home story.
Tread, Riser, Stair Structure: The related Zone of its parent Stair
Railing subelements: The related Zone of its parent Railing
Related Zone Number - 2D - Number of the element's related Zone in 2D, if any. See explanation for Related Zone Name - 2D, above.
Number of the element's related Zone in 2D, if any. See explanation for Related Zone Name - 2D, above.
Related Zone Name - 3D - Name of the Zone which the element intersects or borders in 3D, if any.
Name of the Zone which the element intersects or borders in 3D, if any.
Related Zone Number - 3D - Number of the element's related Zone in 3D, if any.
Number of the element's related Zone in 3D, if any.
Relative Top Link Story - Relative position of elements top-linked Story.
Relative position of elements top-linked Story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: Home + 1 - Slant Angle
Slant Angle - Angle of slanted or inclined element.
Angle of slanted or inclined element. - For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
Beam: Angle of an inclined Beam - CW Frame or Panel: Slant angle measured to the horizontal plane.
CW Frame or Panel: Slant angle measured to the horizontal plane.
Surface Area - Generally: the sum of all surfaces of an element.
Generally: the sum of all surfaces of an element.
Beam: The sum of all Beam surfaces (top, bottom, ends)
Column: Surface area of the Column's cross-section - Shell: Net surface area of the Reference Side
Shell: Net surface area of the Reference Side
Thickness - Element Thickness, as defined in Element Settings.
Element Thickness, as defined in Element Settings.
Width - Element Width parameter, as defined by its geometry or in Element Settings.
Element Width parameter, as defined by its geometry or in Element Settings.
Object: Width of the Object as defined in the Dimension 1 field of the Preview and Positioning Panel of Object Settings.
Column: Width of the column: Core Dimension 1 value, plus the width of any veneer.
Bottom Surface - Name of the Surface assigned to the Bottom Surface of the Slab.
Name of the Surface assigned to the Bottom Surface of the Slab.
Defined in Slab Settings - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_BottomMaterial.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_BottomMaterial.png - Bottom Surface Area
Bottom Surface Area - Area of the Surface of the Slab Bottom
Area of the Surface of the Slab Bottom - Reduced by any trims, SEOs or holes.
Reduced by any trims, SEOs or holes.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_BottomSurface.png - Conditional Surface Area of the Bottom
Conditional Surface Area of the Bottom - Surface Area of the Bottom of the Slab - this Area may be conditioned on a defined Calculation Rule.
Surface Area of the Bottom of the Slab - this Area may be conditioned on a defined Calculation Rule.
Condition: Subtracts the Area of holes only if they exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab Surface by)
Reduced by trims and SEOs. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ConditionalBottomSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ConditionalBottomSurface.png - Conditional Surface Area of the Top
Conditional Surface Area of the Top - Surface Area of the Top of the Slab - this Area may be conditioned on a defined Calculation Rule.
Surface Area of the Top of the Slab - this Area may be conditioned on a defined Calculation Rule.
Condition: Subtracts the Area of holes only if they exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Slab Surface by)
Reduced by trims and SEOs. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ConditionalTopSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ConditionalTopSurface.png - Edge Surface
Edge Surface - Name of Surface assigned to Slab edges.
Name of Surface assigned to Slab edges. - Lists the Slabs default edge surface (as defined in its Building Material). Not listed for composite Slabs.
Lists the Slabs default edge surface (as defined in its Building Material). Not listed for composite Slabs.
To list all Surfaces, including custom ones and those of composite elements, use a Surface-type list (e.g. All Finishes).
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_SideMaterial.png - Edge Surface Area
Edge Surface Area - Area of the Surface of the edge of the Slab
Area of the Surface of the edge of the Slab
Reduced by trims and SEOs. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_EdgeSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_EdgeSurface.png - Top Surface
Top Surface - Name of Surface assigned to the Top Surface of the Slab.
Name of Surface assigned to the Top Surface of the Slab.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_TopMaterial.png - Elevation Bottom
Elevation Bottom - Elevation of the Bottom of the Slab
Elevation of the Bottom of the Slab - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ElevationBottom.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ElevationBottom.png - Elevation Top
Elevation Top - Elevation of the Top of the Slab
Elevation of the Top of the Slab - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ElevationTop.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_ElevationTop.png - Gross Surface Area of the Slab Bottom
Gross Surface Area of the Slab Bottom - Area of the Surface of the Bottom of the Slab, including the Surface of any holes.
Area of the Surface of the Bottom of the Slab, including the Surface of any holes.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/SlabGrossBottomholes.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/SlabGrossBottomholes.png - Gross Surface Area of the Slab Bottom with holes
Gross Surface Area of the Slab Bottom with holes
Area of the Surface of the Bottom of the Slab, subtracting the Surface of any holes.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossBottomSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossBottomSurface.png - Gross Surface Area of the Slab edges
Gross Surface Area of the Slab edges - Area of the Surface of all the Slab edges. Hole edges are ignored.
Area of the Surface of all the Slab edges. Hole edges are ignored.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossSurface.png - Gross Surface Area of the Slab edges with holes
Gross Surface Area of the Slab edges with holes
Area of the Surface of all the Slab edges, including the edges of any holes.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossEdgeSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossEdgeSurface.png - Gross Surface Area of the Slab Top
Gross Surface Area of the Slab Top - Area of the Surface of the Top of the Slab, including the Surface of any holes.
Area of the Surface of the Top of the Slab, including the Surface of any holes.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_TopwithHoles.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_TopwithHoles.png - Gross Surface Area of the Slab Top with holes
Gross Surface Area of the Slab Top with holes
Area of the Surface of the Top of the Slab, reduced by the Surface of any holes.
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossTopSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_GrossTopSurface.png - Gross Volume of the Slab, minus the Holes
Gross Volume of the Slab, minus the Holes
Volume of the Slab, subtracting the Volume of any holes. Volume is reduced by any trims, but does not take SEOs into account
Reduced by trims. SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/SlabGrossVolumeHoles.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/SlabGrossVolumeHoles.png - Holes Surface Area
Holes Surface Area - Total Top Surface Area of all holes in the Slab, measured according to the Slabs 2D polygon.
Total Top Surface Area of all holes in the Slab, measured according to the Slabs 2D polygon.
SEOs are ignored - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_HolesSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_HolesSurface.png - Reference Plane Location
Reference Plane Location - Top or Bottom.
Top or Bottom. - For a composite Slab, can also be Core Top or Core Bottom
For a composite Slab, can also be Core Top or Core Bottom
Reference Plane location as defined in Slab Settings.
Top Surface Area - Area of the Surface of the Top of the Slab.
Area of the Surface of the Top of the Slab.
Reduced by any trims, SEOs or holes.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Slab_TopSurface.png - Definition
Definition - 2 quart laboratory safety can
2 quart laboratory safety can - Store and dispense flammable liquids safely with flammable liquid safety cans from Safety Emporium.
Store and dispense flammable liquids safely with flammable liquid safety cans from Safety Emporium.
A combustible material is a solid or liquid than can be easily ignited and burned. OSHA, DOT, and other federal regulations, apply specific technical definitions to this term.
Combustible solids are those capable of igniting and burning. Wood and paper are examples of such materials.
Appendix B of the 2012 revision of 29 CFR 1910.1200, the OHSA Hazard Communication Standard (HCS 2012) defines ready combustible solids as "powdered, granular, or pasty chemicals which are dangerous if they can be easily ignited by brief contact with an ignition source, such as a burning match, and if the flame spreads rapidly."
Combustible liquids are defined by the National Fire Protection Association code NFPA 30 - Flammable and Combustible Liquids Code as "Any liquid that has a closed-cup flash point at or above 100 deg. F (37.8 deg. C), as determined by the test procedures and apparatus set forth in Section 4.4. Combustible liquids are classified according to Section 4.3." You can view (but not copy, save, or distribute) NFPA 30 on the NFPA web site if you want more details on the classes of combustible liquids.
Spontaneously combustible materials can undergo combustion and burn without the addition of heat or flame; arguably, the term "spontaneously flammable" is more appropriate. See the flammable solids entry for more info.
Additional Info - The US Department of Transportation defines the term readily combustible solids at 49 CFR 173.125 (Subpart D) as materials that:
The US Department of Transportation defines the term readily combustible solids at 49 CFR 173.125 (Subpart D) as materials that:
Are solids which may cause a fire through friction, such as matches;
Show a burning rate faster than 2.2 mm (0.087 inches) per second when tested in accordance with the UN Manual of Tests and Criteria (IBR, see 171.7 of this subchapter); or
Any metal powders that can be ignited and react over the whole length of a sample in 10 minutes or less, when tested in accordance with the UN Manual of Tests and Criteria
These are closely related to the third broad class of materials listed under flammable solids.
Prior to 2012, the U.S. Occupational Safety and Health Administration (OSHA) Standard 29 CFR 1910.106 (then titled "Flammable and Combustible Liquids" but now titled simply "Flammable Liquids" ) defined a combustible liquid as "any liquid having a flash point at or above 100 deg. F (37.8 deg. C), but below 200 deg. F (93.3 deg. C), except any mixture having components with flashpoints of 200 deg. F (93.3 deg. C), or higher, the total volume of which make up 99 percent or more of the total volume of the mixture." This definition has been dropped from the current version of 29 CFR 1910.106 which now addresses such materials as flammable in order to bring the standard into compliance with the Globally Harmonized System.
The previous version of 29 CFR 1910.106 is available for historical reference courtesy of the Internet Wayback Machine.
SDS Relevance - Proper storage and use of combustible materials is absolutely critical in maintaining a safe work place. Avoid placing or using combustible materials near sources of heat or flame (direct sunlight, furnaces, pilot lights etc.). Use caution when disposing of combustible materials such as linseed oil-soaked rags (which can spontaneously combust). When dispensing combustible or flammable liquids, keep in mind that static electricity poses a very real threat; obey all standard bonding and grounding practices.
Proper storage and use of combustible materials is absolutely critical in maintaining a safe work place. Avoid placing or using combustible materials near sources of heat or flame (direct sunlight, furnaces, pilot lights etc.). Use caution when disposing of combustible materials such as linseed oil-soaked rags (which can spontaneously combust). When dispensing combustible or flammable liquids, keep in mind that static electricity poses a very real threat; obey all standard bonding and grounding practices.
Two other tools that can be part of your flammable and combustible liquids safety plan are the use of safety cans and flammable storage cabinets. Safety cans have flash arrestors and gasketed lids to prevent solvent vapors from flashing back to the liquid if ignited. Flammable storage cabinets have insulating double walls and automatically closing doors so that stored solvents will not readily ignite in the event of a fire.
Also note that many common dusts such as flours, and grains can readily combust or even explode. See our dust entry for additional information.
fire exit - a door that is used to let people out of a building such as a cinema, hotel, restaurant etc when there is a fire
Missoula Technology and Development Center Facilities Toolbox: Accessibility Tools
Engineering Home | Toolbox Home - When is a facility considered accessible?
When is a facility considered accessible? - A facility is accessible if it was constructed in compliance with the accessibility guidelines that were in force at the time of its construction. Many of our facilities predate accessibility laws, but all Federal facilities must be accessible, with few exceptions , regardless of age. Once we bring a facility up to current accessibility standards and guidelines, that facility is considered accessible even if there are changes to the standards and guidelines later. However, if a facility is altered, reconstructed, or replaced, it must be brought into compliance with the highest standard of Federal or Forest Service accessibility guidelines in place at that time.
A facility is accessible if it was constructed in compliance with the accessibility guidelines that were in force at the time of its construction. Many of our facilities predate accessibility laws, but all Federal facilities must be accessible, with few exceptions , regardless of age. Once we bring a facility up to current accessibility standards and guidelines, that facility is considered accessible even if there are changes to the standards and guidelines later. However, if a facility is altered, reconstructed, or replaced, it must be brought into compliance with the highest standard of Federal or Forest Service accessibility guidelines in place at that time.
The current accessibility guidelines include: - For buildings and related facilities:
For buildings and related facilities: - The combined ADA/ABA Accessibility Guidelines replaced the Uniform Federal Accessibility Standards (UFAS) for Federal and federally-funded facilities and the Americans with Disabilities Act Accessibility Guidelines for places of public accommodation and commercial facilities in the private sector and State and local government facilities when it was published in the Federal Register on July 23, 2004.
The combined ADA/ABA Accessibility Guidelines replaced the Uniform Federal Accessibility Standards (UFAS) for Federal and federally-funded facilities and the Americans with Disabilities Act Accessibility Guidelines for places of public accommodation and commercial facilities in the private sector and State and local government facilities when it was published in the Federal Register on July 23, 2004.
Since 1995, Forest Service policy has been that the Forest Service would use both the Uniform Federal Accessibility Standards (UFAS) and the Americans with Disabilities Act Accessibility Guidelines (ADAAG). When both standards covered the same features, the Forest Service used the higher standard. This policy is contained in Forest Service Handbook 7309.11Buildings and Related Facilities Handbook, Zero Code. Now, there is only the one combined standard.
For developed recreation areas: - The Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG) apply to Forest Service outdoor recreation areas.
The Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG) apply to Forest Service outdoor recreation areas.
The Forest Service Trails Accessibility Guidelines (FSTAG) apply to Forest Service trails managed for hikers and pedestrians.
The ADAAG Recreation Facilitiesapplies to boating facilities, fishing piers and platforms, golf courses, miniature golf courses, amusement rides, sports facilities, and swimming pools and spas in the private sector and to state and local government facilities. The Forest Service should also follow these guidelines based on the policy above.
The ADAAG Children's Play Areas applies to children's play areas in the private sector and to state and local government facilities. The Forest Service should also follow these guidelines per the policy above.
A site, facility, or program either meets the requirements of the Federal accessibility standards and guidelines and is accessible or it does not meet the requirements and is not accessible. Plans for some recreation site amenities that meet the requirements of the Federal accessibility standards are available to Forest Service employees at the Accessible Recreation Facilities site.
Two terms that are not correct are "ADA accessible" and "handicapped accessible."
Why not "ADA accessible"? The Americans with Disabilities Act (ADA) is not an accessibility guideline, it is a law. The Americans with Disabilities Act Accessibility Guidelines (ADAAG) is one of the accessibility guidelines. If a person is stating that the facility is in compliance with the ADAAG, verses the UFAS or the FSORAG, then that statement should be made in full. However there is generally no need to be that specific. Simply stating that the facility is accessible means it is in compliance with the highest accessibility guidelines for that type of facility.
Why not use the phrase "handicapped accessible"? A handicap is a barrier, such as stairs that handicap passage by a person using a wheelchair. The term "accessible" means "in compliance with the accessibility guidelines." An accessible facility has no barriers. So the term "handicap accessible" means "barrier-no barrier," which makes no sense. The correct terms are simply "accessible" and "not accessible."
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USDA Forest Service, Technology and Development - Last Modified: 03/09/2018 01:53:25
Last Modified: 03/09/2018 01:53:25
fragility - quality of being easily damaged or destroyed.
Position - the particular portion of space occupied by something
Between two floors, the headroom is the clear vertical space between the two decks, from the top of the finished floor level of the lower deck, to the underside of the soffit of the upper deck. Low headroom may increase the likelihood of injury or the difficulty of manoeuvring large objects.
Width is defined as the quality of being wide, or the measurement of distance from side to side.
Weight - the vertical force exerted by a mass as a result of gravity of component
Lifting weight: the vertical force exerted by a mass as a result of gravity of raise from a lower to a higher position
Construction Type - Type of Stair Structure: Monolith, Beam, Stringers, or Cantilevered
Type of Stair Structure: Monolith, Beam, Stringers, or Cantilevered
Drain Length - Length of Draining (Monolith Structure only)
Length of Draining (Monolith Structure only) - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/379_drain_length.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/379_drain_length.png - Drain Position
Drain Position - Position of Draining (Right and/or Left, relative to direction of Stair baseline).
Position of Draining (Right and/or Left, relative to direction of Stair baseline).
Assign in "Draining on Flight" Panel of Stair Settings (Monolithic Structure only)
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/380_drain_position.gif - Profile Height
Profile Height - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/381_profile_height.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/381_profile_height.png - Profile Width
Profile Width - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/382_profile_width.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/382_profile_width.png - Profile WxH
Profile WxH - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/383_profile_WxH.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/383_profile_WxH.png - Secondary Thickness
Secondary Thickness - As in Settings - relevant for Monolithic Flight Structures using a Stepped or Variable shape.
As in Settings - relevant for Monolithic Flight Structures using a Stepped or Variable shape.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/384_secondary_thickness.gif - Shape Type
Shape Type - Shape of Stair bottom, as defined in Flight Structure Settings.
Shape of Stair bottom, as defined in Flight Structure Settings.
Flat, Stepped, Variable, or Filled (for Monolithic Flight Structures)
Straight or Stepped (for Beam-type Flights) - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/385_stair_shape_type.gif
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/385_stair_shape_type.gif - Stair Structure 3D Height
Stair Structure 3D Height - Height of Stair structure in 3D
Height of Stair structure in 3D - Measured from the flight's lowest to highest z-point
Measured from the flight's lowest to highest z-point - Stair Structure Flight Index
Stair Structure Flight Index - Flight number
Flight number - Flight structures are numbered consecutively
Flight structures are numbered consecutively - Stair Structure Landing Index
Stair Structure Landing Index - Landing number
Landing number - Landing structures (if any) are numbered consecutively
Landing structures (if any) are numbered consecutively
Stair Structure Position - For Stringers: Left or Right position. All other Structures are listed as "Under Stair."
For Stringers: Left or Right position. All other Structures are listed as "Under Stair."
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/387_stringer_position.gif - Thickness
Thickness - Thickness of Structure element (as in Settings).
Thickness of Structure element (as in Settings).
Component Cross Section Area - Area of the Component cross-section
Area of the Component cross-section - Component Type
Component Type - Core, Finish, or Other.
Core, Finish, or Other - Embodied Carbon.
Embodied Carbon - As defined for the components Building Material
As defined for the components Building Material - Embodied Energy
Embodied Energy - As defined for the components Building Material
As defined for the components Building Material - Mass
Mass - Calculated based on components volume and the Building Materials Density value
Calculated based on components volume and the Building Materials Density value
Skin Thickness - As defined in the component
As defined in the component - Projected Component/Skin Area
Projected Component/Skin Area - The projection onto the virtual plane that runs through the center of the skin/component.
The projection onto the virtual plane that runs through the center of the skin/component.
See Projected Skin Areas of Basic and Composite Elements and Component Areas of Complex Profiles.
Rectangular Component Height - Height of rectangular component in 2D
Height of rectangular component in 2D - Rectangular Component Width
Rectangular Component Width - Width of rectangular component in 2D
Width of rectangular component in 2D - Skin/Component Fill Outline Pen
Skin/Component Fill Outline Pen - Pen number
Pen number - Skin/Component Volume
Skin/Component Volume - Volume of the skin or component
Volume of the skin or component - Walls, Slabs, Roofs and Shells can be defined as composite structures.
Walls, Slabs, Roofs and Shells can be defined as composite structures.
Assign a Composite Structure to a Wall, Slab, Roof or Shell
1.Open the Element Settings dialog box for the element type.
2.In the Geometry and Positioning Panel, define the elements structure as a composite by clicking on the Composite icon.
//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/020-configuration/ChooseWallComposite.png - 3.Use the pop-up below to choose a composite structure. Notice the icon that indicates whether the selected composite contains a Core or not. (In this image, the icon indicates No Core.)
3.Use the pop-up below to choose a composite structure. Notice the icon that indicates whether the selected composite contains a Core or not. (In this image, the icon indicates No Core.)
//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/020-configuration/ChooseComposite.png - Note: Composite Structures are defined for specific element types: Wall, Slab, Roof, and/or Shell, by the Use With control, in the Options > Element Attributes > Composites. The composite structure pop-up in element Settings shows only those Composite Structures whose Use With control includes the element type you are defining. Composites are defined at Options > Element Attributes > Composites
Note: Composite Structures are defined for specific element types: Wall, Slab, Roof, and/or Shell, by the Use With control, in the Options > Element Attributes > Composites. The composite structure pop-up in element Settings shows only those Composite Structures whose Use With control includes the element type you are defining. Composites are defined at Options > Element Attributes > Composites
See Composite Structures Dialog Box. - You can also edit a selected composite by accessing its settings from its context menu:
You can also edit a selected composite by accessing its settings from its context menu:
//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/020-configuration/EditSelectedComposite.png - 4.The chosen composite structure is applied to the currently selected or created element.
4.The chosen composite structure is applied to the currently selected or created element.
Note: The views models Partial Structure Display settings will affect the display of composite elements.
See Partial Structure Display. - Components of Composite Structures
Components of Composite Structures - The layers of the composite element are called skins; a composite structure can have up to 48 skins.
The layers of the composite element are called skins; a composite structure can have up to 48 skins.
The skins are separated by separator lines; and the outline of the composite is the contour line.
Composite elements can include one or more structural skin called a Core, although defining a Core skin is not required.
The skins you define as Core or Finish will also affect views in Partial Structure Display.
See Partial Structure Display. - Assign these definitions in the Options > Element Attributes > Composites.
Assign these definitions in the Options > Element Attributes > Composites.
//helpcenter.graphisoft.com/wp-content/uploads/ac22_help/020-configuration/CoreFinish.png - Beam Offset
Beam Offset - Reference line axis offset.
Reference line axis offset. - in Beam Settings: optional offset from Reference Axis.
in Beam Settings: optional offset from Reference Axis.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_Offset.png - Beam (Segment) Cross Section
Beam (Segment) Cross Section - Rectangular, Profiled or Rounded
Rectangular, Profiled or Rounded - Shape of the Beams cross-section as defined in the Beam Settings dialog box.
Shape of the Beams cross-section as defined in the Beam Settings dialog box.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_CrossSection.png - Beam Slant Angle
Beam Slant Angle - Same as the General Slant Angle parameter
Same as the General Slant Angle parameter - Beam (Segment) End Surface
Beam (Segment) End Surface - Name of the Surface assigned to the two ends of the Beam.
Name of the Surface assigned to the two ends of the Beam.
Defined in Beam Settings (via Building Material, or Override in Model Panel)
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_EndMaterial.png - Beam (Segment) Extrusion Surface
Beam (Segment) Extrusion Surface - Name of the Surface assigned to the Beam extrusion
Name of the Surface assigned to the Beam extrusion
Use with round and profiled beams, which use a single surface on all sides of the extrusion. (Same value as the Left Side Surface parameter.)
Beam (Segment) End Surface Area - Area of the Surfaces of both ends of the Beam
Area of the Surfaces of both ends of the Beam
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_EndSurface.png - Beam Hole Height
Beam Hole Height - Height or diameter of the first-placed hole in the Beam).
Height or diameter of the first-placed hole in the Beam).
Same value as Hole Height or Diameter, on the Hole panel of Beam Tool Settings
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HoleHeight.png - Beam Hole Position from Reference Line
Beam Hole Position from Reference Line - Distance of the centerpoint of the first-placed hole from the edge of the Beam
Distance of the centerpoint of the first-placed hole from the edge of the Beam
Same value as Position, on the Hole panel of Beam Tool Settings.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HoleLevel.png - Beam Hole Number
Beam Hole Number - Total number of holes in the Beam.
Total number of holes in the Beam. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HoleNumber.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HoleNumber.png - Beam Hole Width
Beam Hole Width - Width of the first-placed hole in the Beam
Width of the first-placed hole in the Beam - Same value as Hole Height, on the Hole panel of Beam Tool Settings.
Same value as Hole Height, on the Hole panel of Beam Tool Settings.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HoleWidth.png - Beam Holes Edge Surface Area
Beam Holes Edge Surface Area - Total edge area of all Beam holes
Total edge area of all Beam holes - Beam Holes Surface Area
Beam Holes Surface Area - Total area of the 2D Surface of all holes, as calculated on one Side of the Beam.
Total area of the 2D Surface of all holes, as calculated on one Side of the Beam.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HolesSurface.png - Beam Holes Volume
Beam Holes Volume - Total volume of all holes in the Beam.
Total volume of all holes in the Beam.
Multiplies Beam Width by Holes Surface Area. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HolesVolume.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_HolesVolume.png - Length Left
Length Left - Beam length on its left side.
Beam length on its left side. - Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam
Length Right - Beam length on its right side.
Beam length on its right side. - Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam
Beam (Segment) Left Side Surface - Name of the Surface assigned to the left Side of the Beam.
Name of the Surface assigned to the left Side of the Beam.
Defined in Beam Settings (via Building Material, or Override in Model Panel)
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_LeftMaterial.png - Beam (Segment) Left Side Surface Area
Beam (Segment) Left Side Surface Area - Area of the Surface of the left Side of the Beam
Area of the Surface of the left Side of the Beam
reduced by any SEOs or holes - Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_LeftSurface.png - Beam (Segment) Right Side Surface
Beam (Segment) Right Side Surface - Name of the Surface assigned to the right Side of the Beam.
Name of the Surface assigned to the right Side of the Beam.
Defined in Beam Settings (via Building Material, or Override in Model Panel)
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_RightSurface.png - Beam (Segment) Right Side Surface Area
Beam (Segment) Right Side Surface Area - Area of the Surface of the right Side of the Beam
Area of the Surface of the right Side of the Beam
reduced by any SEOs or holes - Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_RightSurface00104.png - Beam (Segment) Bottom Surface
Beam (Segment) Bottom Surface - Name of the Surface assigned to the bottom of the Beam.
Name of the Surface assigned to the bottom of the Beam.
Defined in Beam Settings (via Building Material, or Override in Model Panel)
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_BottomMaterial.png - Beam (Segment) Bottom Surface Area
Beam (Segment) Bottom Surface Area - Area of the Surface of the bottom of the Beam
Area of the Surface of the bottom of the Beam
reduced by any SEOs or holes. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_BottomSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_BottomSurface.png - Beam (Segment) Top Surface
Beam (Segment) Top Surface - Name of the Surface assigned to the top of the Beam.
Name of the Surface assigned to the top of the Beam.
Defined in Beam Settings (via Building Material, or Override in Model Panel)
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_TopMaterial.png - Beam (Segment) Top Surface Area
Beam (Segment) Top Surface Area - Area of the Surface of the top of the Beam
Area of the Surface of the top of the Beam
reduced by any SEOs or holes. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_TopSurface.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-23-reference-guide/060_elementparameters/Beam_TopSurface.png - Was this Helpful ?
Was this Helpful ? - Construction Type
Construction Type - Type of Stair Structure: Monolith, Beam, Stringers, or Cantilevered
Type of Stair Structure: Monolith, Beam, Stringers, or Cantilevered
Drain Length - Length of Draining (Monolith Structure only)
Length of Draining (Monolith Structure only) - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/379_drain_length.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/379_drain_length.png - Drain Position
Drain Position - Position of Draining (Right and/or Left, relative to direction of Stair baseline).
Position of Draining (Right and/or Left, relative to direction of Stair baseline).
Assign in "Draining on Flight" Panel of Stair Settings (Monolithic Structure only)
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/380_drain_position.gif - Profile Height
Profile Height - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/381_profile_height.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/381_profile_height.png - Profile Width
Profile Width - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/382_profile_width.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/382_profile_width.png - Profile WxH
Profile WxH - Profile dimension of the supporting Structure.
Profile dimension of the supporting Structure. - Not relevant for Monolithic structure.
Not relevant for Monolithic structure. - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/383_profile_WxH.png
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/383_profile_WxH.png - Secondary Thickness
Secondary Thickness - As in Settings - relevant for Monolithic Flight Structures using a Stepped or Variable shape.
As in Settings - relevant for Monolithic Flight Structures using a Stepped or Variable shape.
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/384_secondary_thickness.gif - Shape Type
Shape Type - Shape of Stair bottom, as defined in Flight Structure Settings.
Shape of Stair bottom, as defined in Flight Structure Settings.
Flat, Stepped, Variable, or Filled (for Monolithic Flight Structures)
Straight or Stepped (for Beam-type Flights) - https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/385_stair_shape_type.gif
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/385_stair_shape_type.gif - Stair Structure 3D Height
Stair Structure 3D Height - Height of Stair structure in 3D
Height of Stair structure in 3D - Measured from the flight's lowest to highest z-point
Measured from the flight's lowest to highest z-point - Stair Structure Flight Index
Stair Structure Flight Index - Flight number
Flight number - Flight structures are numbered consecutively
Flight structures are numbered consecutively - Stair Structure Landing Index
Stair Structure Landing Index - Landing number
Landing number - Landing structures (if any) are numbered consecutively
Landing structures (if any) are numbered consecutively
Stair Structure Position - For Stringers: Left or Right position. All other Structures are listed as "Under Stair."
For Stringers: Left or Right position. All other Structures are listed as "Under Stair."
https://helpcenter.graphisoft.com/wp-content/uploads/archicad-24/060_elementparameters/387_stringer_position.gif - Thickness
Thickness - Thickness of Structure element (as in Settings).
Thickness of Structure element (as in Settings).
2D Cross Section Preview - 2D Plan Preview
2D Plan Preview - 3D Axonometry
3D Axonometry - 3D Back View
3D Back View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
3D Symbol of the Frame. - Back = inside of the Curtain Wall
Back = inside of the Curtain Wall - 3D Front View
3D Front View - Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
Shaded 3D Symbol of the GDL element (Object, Lamp, Skylight, CW Panel, CW Frame).
3D Symbol of the Frame (from the front, that is, the outside of the Curtain Wall).
Front = outside of the Curtain Wall - 3D Holes Perimeter
3D Holes Perimeter - Total Perimeter of all the holes in the Shell or Roof. Does not take SEO's into account.
Total Perimeter of all the holes in the Shell or Roof. Does not take SEO's into account.
Relevant for Roof or Shell. - 3D Left Side View
3D Left Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the Accessory viewed from its left side.
3D Length - Maximum 3D length of construction element
Maximum 3D length of construction element - Available for
Available for - - Wall
- Wall - - Beam/Beam Segment
- Beam/Beam Segment - - Column/Column Segment
- Column/Column Segment - - Railing/Railing Segment
- Railing/Railing Segment - - Stair Structure
- Stair Structure - 3D Perimeter
3D Perimeter - Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Total perimeter of the 3D shape of the element, including the perimeter of any holes.
Relevant for Roof, Shell, CW Panel - 3D Right Side View
3D Right Side View - Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Shaded 3D Symbol of the Object/Lamp or CW Junction/Accessory.
Cross-section of the Accessory viewed from its right side
Absolute Top Link Story - Name of the element's top-linked story.
Name of the element's top-linked story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: 1. Story - ARCHICAD IFC ID
ARCHICAD IFC ID - The Globalid IFC attribute automatically assigned by ARCHICAD to each element
The Globalid IFC attribute automatically assigned by ARCHICAD to each element
Area - For most elements: area includes the full extent of the element surface geometry (net of any holes) viewed from the top, as projected down to the floor plan.
For most elements: area includes the full extent of the element surface geometry (net of any holes) viewed from the top, as projected down to the floor plan.
For a Column (or column segment): Area of the column's bottom polygon only, as projected to the floor plan.
For a Wall: Area of the Wall's bottom polygon only, as projected to the floor plan.
Building Material - Name of the element's Building Material
Name of the element's Building Material - For non-composite, non-complex profile elements
For non-composite, non-complex profile elements - Building Material / Composite / Profile / Fill
Building Material / Composite / Profile / Fill - Name of the element's Building Material, or its composite structure, or its profile, or its fill
Name of the element's Building Material, or its composite structure, or its profile, or its fill
Building Materials (All) - Lists all of the element's Building Materials in a single Schedule cell
Lists all of the element's Building Materials in a single Schedule cell
Colliding Zones - The name of the Zone with which the element collides in 3D.
The name of the Zone with which the element collides in 3D.
Elements must intersect the Zone to be considered as "Colliding". Bordering the Zone is not considered collision.
For Columns: If its Relation to Zones option is set to "Zone Boundary" or "No Effect on Zones", it is not considered collision, even if it is located in the Zone.
Complex Profile - For a complex profile element: Name of the profile
For a complex profile element: Name of the profile
Composite Structure - For a composite element: Name of the composite attribute
For a composite element: Name of the composite attribute
Conditional Volume - Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
Volume of Construction element (Beam, Roof, Shell, Slab, or Wall).
This volume may be conditioned on a defined Calculation Rule.
Condition: subtracts the volume of any openings that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules ("Reduce element volume by").
Reduced by trims and SEO's. - Cover Fill
Cover Fill - Name of the Cover Fill assigned to the element (if any).
Name of the Cover Fill assigned to the element (if any).
Cover Fills are available for Zone, Mesh, Slab, Roof, Column, Beam, Morph, Opening.
Cross Section Area at Bottom/Start - Area of the element's bottom cross section.
Area of the element's bottom cross section. - Relevant for Beams and Columns and their segments
Relevant for Beams and Columns and their segments - For Columns: Includes the area of the Veneer, if any.
For Columns: Includes the area of the Veneer, if any.
Cross Section Area at Top/End - Area of the element's top cross section.
Area of the element's top cross section. - Relevant for Beams and Columns and their segments
Relevant for Beams and Columns and their segments - For Columns: Includes the area of the Veneer, if any.
For Columns: Includes the area of the Veneer, if any.
Cross Section Height at Bottom/Start (cut)
Height of the element's bottom cross section. - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Height at Bottom/Start (perpendicular)
new - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Height at Top/End (cut)
Height of the element's top cross section. - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Height at Top/End (perpendicular)
new - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Width at Bottom/Start (cut)
Width of the element's bottom/top cross section.
Relevant for Beams and Columns and their segments.
Cross Section Width at Bottom/Start (perpendicular)
new - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Width at Top/End (cut)
Width of the element's top cross section. - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Cross Section Width at Top/End (perpendicular)
new - Relevant for Beams and Columns and their segments.
Relevant for Beams and Columns and their segments.
Element ID - Lists Element ID.
Lists Element ID. - For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
For each element: editable ID field is located on the Classification and Properties panel of construction tools, Fill and Zone tools.
Element Type - Type of AC element
Type of AC element - Elevation to 1st/2nd Reference Level
Elevation to 1st/2nd Reference Level - Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Element's elevation relative to the project's 1st and/or 2nd Elevation Level.
Elevation levels are defined at Options > Project Preferences > Reference Levels.
Element's elevation value (measured from its reference line/point) is displayed in its Info box or Settings.
Elevation to Linked/Home Story - Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Element's elevation relative to its linked story (Door/Window) or Home Story (other elements).
Relevant for Doors/Windows. Value is the door/window elevation from its linked (anchor) story to its sill height.
Elevation to Project Zero - Element's absolute elevation, measured from zero.
Element's absolute elevation, measured from zero. - Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels.
Project Zero is always at zero for the purposes of measuring actual element elevation. To set other reference levels, use Options > Project Preferences > Reference Levels.
Element's elevation value (measured from its reference line/point) is displayed in its Info box or Settings.
Elevation to Sea Level - Element's elevation relative to Sea Level (Altitude of the Project Location).
Element's elevation relative to Sea Level (Altitude of the Project Location).
Define Sea Level value (Altitude) at Options > Project Preferences > Project Location.
Element's elevation value (measured from its reference line/point) is displayed in its Info box or Settings.
External IFC ID - The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
The Globalid IFC attribute assigned to each element upon IFC import (either Merge or Hotlink IFC)
Fill Type - Name of the Fill attribute assigned to the element
Name of the Fill attribute assigned to the element
To list the type of the Fill pattern (e.g. Solid, Vectorial, Symbol, Image) instead: Use the Fill Type parameter in the "General" parameter group.
Floor Plan Holes Perimeter - Total Perimeter of all the holes in the element.
Total Perimeter of all the holes in the element.
Relevant for Slab, Mesh, Zone - Floor Plan Perimeter
Floor Plan Perimeter - Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Perimeter of the element, including hole perimeters. Measured according to the element's 2D polygon
Relevant for Wall, Slab, Mesh, Morph
For Wall: Perimeter can vary depending on its Floor Plan Projection settings (e.g. Cut Only vs. Projected with Overhead)
Wall intersections have no effect on the perimeter value.
From Zone - Name of the Zone from which the element opens.
Name of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Zone (if any) from which the Panel faces outward. (The Zone that abuts the panel's inside surface.)
From Zone Number - Number of the Zone from which the element opens.
Number of the Zone from which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Number of the Zone (if any) from which the Panel faces outward. (The Zone that abuts the panel's inside surface.)
GDL Preview Picture - Preview picture, of GDL Object type elements only.
Preview picture, of GDL Object type elements only.
Gross Volume - Volume of the element
Volume of the element - Wall: Includes Volume of Openings, doors and windows.
Wall: Includes Volume of Openings, doors and windows.
Column: Includes Volume of both Core and Veneer.
Roof/Shell/Slab: Includes the volume of any holes. Reduced by trims.
See also the Slab parameter: "Gross Volume of the Slab, Minus the Holes"
Height - D-W: Height of the window/door, as defined in the "Height" field of the opening's Settings dialog box or Info Box.
D-W: Height of the window/door, as defined in the "Height" field of the opening's Settings dialog box or Info Box.
Height of the panel, not including the panel's extrusion into the surrounding frames.
Curtain Wall: defined in Curtain Wall System Settings or the Info Box
Curtain Wall Panel: Height of the panel, not including the panel's extrusion into the surrounding frames.
Zone: Height of the Zone body measured from the Zone's bottom elevation. Defined in the Name and Positioning Panel of Zone Settings.
Skylight: Height parameter in the Preview and Positioning Panel (or the Skylight Settings Panel)
Home Offset - Offset of element from its Home Story.
Offset of element from its Home Story. - For Door/Window: The sill height, measured from the host Wall's home story.
For Door/Window: The sill height, measured from the host Wall's home story.
Home Story Name - Name of element's Home Story
Name of element's Home Story - As defined in Element settings.
As defined in Element settings. - Openings: Home Story depends on the opening's vertical position in the host element.
Openings: Home Story depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Home Story Number - Number of element's Home Story
Number of element's Home Story - As defined in Element settings.
As defined in Element settings. - Door/Window: Home Story depends on the opening's vertical position in the host element.
Door/Window: Home Story depends on the opening's vertical position in the host element.
Skylight: Home Story is the same as the host Roof/Shell.
Hotlink and Element ID - If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
If element is part of a Hotlink: Lists the Hotlink's Master ID as well as the Element's ID
Hotlink Master ID - If element is part of a Hotlink: Lists the Hotlink's Master ID only
If element is part of a Hotlink: Lists the Hotlink's Master ID only
ID of Connected Openings - IDs of opening(s) connected to this element.
IDs of opening(s) connected to this element.
IFC Assignment - Name of IFC Assignment (if any) to which element belongs.
Name of IFC Assignment (if any) to which element belongs.
IFC Assignment takes place in IFC Project Manager. Assignments include e.g. IFC Group, IFC Zone, IFC System.
IFC Type - Name of element's IFC Type
Name of element's IFC Type - Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel), and in IFC Project Manager. IFC Type depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
Classification of ARCHICAD elements for IFC is displayed in Element Settings (Classification and Properties panel), and in IFC Project Manager. IFC Type depends on "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box)
IFC Type Product - Lists the element's IFC Type Product Type and IFC Type Product Name.
Lists the element's IFC Type Product Type and IFC Type Product Name.
IFC Type Product is defined in the "Type Mapping for Export" setting of the current Preview Translator (IFC Translators dialog box), and is displayed in IFC Project Manager.
Insulation Skin Thickness - Thickness of Wall, Roof, or Shell skins whose structure is defined as "Insulation"
Thickness of Wall, Roof, or Shell skins whose structure is defined as "Insulation"
Insulation Skin (Wall, Roof, Shell) is defined at Options > Project Preferences > Calculation Units & Rules.
Issue Date (of last Change) - Issue ID (of last Change)
Issue ID (of last Change) - Issue Name (of last Change)
Issue Name (of last Change) - Layer
Layer - Layer of element.
Layer of element. - Length
Length - Length of element.
Length of element. - Library Part Name
Library Part Name - Name, of GDL Object type elements only.
Name, of GDL Object type elements only.
Linked Changes - If element or sub-element is linked to a Change: lists the number of the linked Change(s)
If element or sub-element is linked to a Change: lists the number of the linked Change(s)
Locked - Element's locked/unlocked status
Element's locked/unlocked status - This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
This is a toggle (yes/no) value expressed as a checkbox in the Schedule field.
Net Volume - Net volume of the element. Reduced by volume of holes and Solid Element Operations .
Net volume of the element. Reduced by volume of holes and Solid Element Operations .
Column: (including the volume of the core and of the veneer, if any).
Roof-Shell-Slab-Mesh: is reduced by the surface of any holes. Reduced by trims and SEO's.
Wall/Beam/Morph: reduced by holes and SEO's
Door-Window: Volume of the opening cut by the Door/Window. (Volume calculation based on hole that results from cutting the GDL openings out of the Wall.)
Number of Openings - Number of Opening elements.
Number of Opening elements. - Opening elements only (not Doors, Windows, or Skylights).
Opening elements only (not Doors, Windows, or Skylights).
Number of Segments - (new)
(new) - Parent ID
Parent ID - Element ID of the listed element's parent element
Element ID of the listed element's parent element - Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall, or Segment of a Beam/Column, or Door/Window/Skylight/Opening)
Relevant for sub-elements (e.g. Tread of Stair, or Panel of Curtain Wall, or Segment of a Beam/Column, or Door/Window/Skylight/Opening)
Position - Value of element's "Position" classification
Value of element's "Position" classification - Possible values: Interior, Exterior, Undefined
Possible values: Interior, Exterior, Undefined - Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Position is set in Classification and Properties panel of Element Settings. Used for IFC data exchange.
Property Object Name - Name of property object (if any) linked to this element.
Name of property object (if any) linked to this element.
Property Objects can be linked to elements using the Listing panel of Element Settings. (This panel is hidden by default. Consult the Calculation Guide for details.)
Quantity - For a particular listed element, displays the number of scheduled elements.
For a particular listed element, displays the number of scheduled elements.
Related Zone Name - Name of the element's related Zone, if any.
Name of the element's related Zone, if any.
In general: the Zone which the element borders or intersects in 2D.
Related Zone definitions vary by element. See Description.
An element can have only one Related Zone. (If multiple Zones apply, the first created Zone is listed.)
(To identify the Zone with which an element intersects in 3D, use the "Colliding Zones" parameter.)
Wall: The Zone which it borders, or the Zone which the Wall's 2D polygon intersects
Door/Window: Related Zone of the host Wall.
Curtain Wall: The Zone which it (or at least one of its segments) borders
Curtain Wall Frame/Panel: The Zone which its CW segment borders, and which the Frame/Panel touches.
Curtain Wall Junction: All of the connecting subelements (at the Junction's gridpoint) border the Zone; or two of the connecting Frames (at the Junction's gridpoint) border the Zone
Curtain Wall Accessory: The Zone bordered by the Accessory's parent Frame.
Shell/Roof: The Zone to which it connects via SEO, or by which it is cropped
Object, Light, Morph, Stair, Railing: The Zone that has the same Home Story as the element. For an Object: the centerpoint of its 3D bounding box is within the Zone polygon.
Beam: The Zone which the Beam's Reference line intersects in 2D. The Beam must be visible on this related Zone's home story.
Skylight: The Zone to which its parent Roof or Shell connects via SEO, or by which it is cropped.
Column: The Zone polygon intersected by any corner of the Column. The Column must be visible on this related Zone's home story.
Tread, Riser, Stair Structure: The related Zone of its parent Stair
Railing subelements: The related Zone of its parent Railing
Related Zone Number - Number of the element's related Zone, if any. See explanation for Related Zone Name, above.
Number of the element's related Zone, if any. See explanation for Related Zone Name, above.
Relative Top Link Story - Relative position of element's top-linked Story.
Relative position of element's top-linked Story. - Relevant for Wall/Column/Zone/Stair
Relevant for Wall/Column/Zone/Stair
For example: Home + 1 - Renovation Status
Renovation Status - Existing, To Be Demolished, or New
Existing, To Be Demolished, or New - As set in element's Classification and Properties panel, or Renovation palette
As set in element's Classification and Properties panel, or Renovation palette
Show On Renovation Filter - Renovation Filter on which this element is shown
Renovation Filter on which this element is shown - As set in element's Classification and Properties panel, or Renovation palette
As set in element's Classification and Properties panel, or Renovation palette
Slant Angle - Angle of slanted or inclined element.
Angle of slanted or inclined element. - For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
For Wall: Same as Wall Outside Slant Angle. (See also Wall-specific Inside Slant Angle parameter).
Beam: Angle of an inclined Beam - CW Frame or Panel: Slant angle measured to the horizontal plane.
CW Frame or Panel: Slant angle measured to the horizontal plane.
Structural Function - Load-bearing, or Non-load -bearing, or undefined
Load-bearing, or Non-load -bearing, or undefined
As set in element's Classification and Properties panel - Structure Type
Structure Type - Basic, Composite, or Complex Profile
Basic, Composite, or Complex Profile - Surface (All)
Surface (All) - List of all surfaces used in the element, including any overrides
List of all surfaces used in the element, including any overrides
Surface Area - Generally: the sum of all surfaces of an element.
Generally: the sum of all surfaces of an element.
Beam: The sum of all Beam surfaces (top, bottom, ends)
Column: Surface area of the Column's cross-section - Shell: Net surface area of the Reference Side
Shell: Net surface area of the Reference Side
Thickness - Element Thickness, as defined in Element Settings.
Element Thickness, as defined in Element Settings.
To Zone - Name of the Zone toward which the element opens.
Name of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the panel's outside surface.
To Zone Number - Number of the Zone toward which the element opens.
Number of the Zone toward which the element opens.
Relevant for Door, Window, Skylight, CW Panel
CW Panel: Name of the Zone (if any) that abuts the Panel's outside surface.
Top Link Story - Element's top-linked Story, expressed as both relative and absolute.
Element's top-linked Story, expressed as both relative and absolute.
Relevant for Wall/Column/Zone/Stair
For example: Home + 1 (2. Story)
Top Offset - Offset from element's Toplink Story
Offset from element's Toplink Story - Applicable to elements with a top link: Wall, Column, Zone, Stair
Applicable to elements with a top link: Wall, Column, Zone, Stair
Top/Bottom Elevation to Reference Level - Elevation of the element's topmost (or bottom) point in 3D space (regardless of its reference line or anchor point).
Elevation of the element's topmost (or bottom) point in 3D space (regardless of its reference line or anchor point).
Use the parameter corresponding to the desired reference level for the measured elevation: First/Second Reference Level, Home Story, Project Zero or Sea Level.
Define levels at Options > Project Preferences > Reference Levels.
Unique ID - Automatically generated ID that is conserved throughout the life of the project
Automatically generated ID that is conserved throughout the life of the project
Also known as the element's ARCHICAD "Global unique identifier" (GUID).
Width - Element Width parameter, as defined by its geometry or in Element Settings.
Element Width parameter, as defined by its geometry or in Element Settings.
Object: Width of the Object as defined in the "Dimension 1" field of the Preview and Positioning Panel of Object Settings.
Column: Width of the column: Core Dimension 1 value, plus the width of any veneer.
BEAM FIELD - DESCRIPTION
DESCRIPTION - Beam Cross Section
Beam Cross Section - Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Shape of the Beams cross-section (either regular or complex) as defined in the Beam Settings dialog box.
Beam_CrossSection.png - Building Material/Composite/Profile
Building Material/Composite/Profile - Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Name of the Building Material assigned to the Beam (or the name of the Composite or the Profile, in case of a profiled or composite Beam.)
Beam_CutFillType.png - Height
Height - Height of the Beam (difference between its base elevation and its top elevation)
Height of the Beam (difference between its base elevation and its top elevation)
Beam_Height.png - Hole Height
Hole Height - Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Height or diameter of the first-placed hole in the Beam (same value as Hole Dimension 2 or diameter on the Hole panel of Beam Tool Settings).
Beam_HoleHeight.png - Hole Level
Hole Level - Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Distance of the centerpoint of the first-placed hole from the edge of the Beam (same value as Position on the Hole panel of Beam Tool Settings.)
Beam_HoleLevel.png - Hole Number
Hole Number - Total number of holes in the Beam.
Total number of holes in the Beam. - Beam_HoleNumber.png
Beam_HoleNumber.png - Hole Width
Hole Width - Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Width of the first-placed hole in the Beam (same value as Hole Dimension 1 on the Hole panel of Beam Tool Settings.
Beam_HoleWidth.png - Holes Surface Area
Holes Surface Area - Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Total area of the 2D surface of all holes, as calculated on one side of the Beam.
Beam_HolesSurface.png - Holes Volume
Holes Volume - Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Total volume of all holes in the Beam (multiplying Beam width by the holes surfaces).
Beam_HolesVolume.png - Length Left
Length Left - Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its left side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthLeft.png - Length Right
Length Right - Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Length of the Beam on its right side. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LengthRight.png - Bottom surface
Bottom surface - Name of the surface assigned to the bottom surface of the Beam.
Name of the surface assigned to the bottom surface of the Beam.
Beam_BottomMaterial.png - Left side surface
Left side surface - Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the left surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftMaterial.png - Right side surface
Right side surface - Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Name of the surface assigned to the right surface of the Beam. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightMaterial.png - End surface
End surface - Name of the surface assigned to the two end surfaces of the Beam.
Name of the surface assigned to the two end surfaces of the Beam.
Beam_EndMaterial.png - Top surface
Top surface - Name of the surface assigned to the top surface of the Beam.
Name of the surface assigned to the top surface of the Beam.
Beam_TopMaterial.png - Offset
Offset - Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Reference line axis offset. By default, this value is zero (the reference axis runs down the center of the Beam). User may assign any other value as offset in Beam Settings: this offsets the reference axis by the given amount from the center.
Beam_Offset.png - Slant Angle
Slant Angle - Angle of an inclined Beam
Angle of an inclined Beam - Beam_SlantAngle.png
Beam_SlantAngle.png - Bottom Surface Area
Bottom Surface Area - Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Area of the surface of the bottom of the Beam, reduced by any SEOs or holes.
Beam_BottomSurface.png - Left side surface area
Left side surface area - Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the left edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_LeftSurface.png - Right side surface area
Right side surface area - Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Area of the surface of the right edge of the Beam, reduced by any SEOs or holes. (Left and Right are determined based on the direction of the Beams reference axis. The axis direction is the direction in which you drag the cursor to draw the Beam.)
Beam_RightSurface.png - End Surface Area
End Surface Area - Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Area of the surfaces of both ends of the Beam, reduced by any SEOs or holes.
Beam_EndSurface.png - Top Surface Area
Top Surface Area - Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Area of the surface of the top of the Beam, reduced by any SEOs or holes.
Beam_TopSurface.png - Volume
Volume - Volume of the Beam, reduced by any SEOs or holes.
Volume of the Beam, reduced by any SEOs or holes.
Beam_Volume.png - Conditional Volume
Conditional Volume - Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Volume of Beam, subtracting the volume of any holes that exceed a given size, as defined in Options > Project Preferences > Calculation Units & Rules (Reduce Beam volume by).
Takes SEOs into account. - Beam_ConditionalVolume.png
Beam_ConditionalVolume.png - Width
Width - Width of the Beam as entered in Info Box or Beam Tool Settings
Width of the Beam as entered in Info Box or Beam Tool Settings
Beam_Width.png - Copyright 2014 by GRAPHISOFT SE. All rights reserved.
Copyright 2014 by GRAPHISOFT SE. All rights reserved.
Base Level - Sets the level for the footprint or extruded roof.
Room Bounding - This is an on/off checkbox. If selected, the roof is part of a room boundary so that room objects calculate volume to the underside of the roof.
Related to Mass - This read-only value indicates if the element was created from a
mass element (roof by face). - Base Offset From Level - Sets the height of the roof above or below the level where it
Base Offset From Level - Sets the height of the roof above or below the level where it
is being sketched (enabled only for roof by footprint).
Cutoff Level - Specifies the level at which the roof should be cut off. Typically, another
roof will be created to fill the hole created by cutting off the first roof. This property and
the Cutoff Offset apply to the first roof, not the second roof (enabled only for roof by
footprint). - Cutoff Offset - The height of the cutoff above or below the level specified by the Cutoff
Cutoff Offset - The height of the cutoff above or below the level specified by the Cutoff
Level (enabled only for roof by footprint).
Extrusion Start - Sets the start point of the extrusion (enabled only for extruded roofs).
Extrusion End - Sets the end point of the extrusion (enabled only for extruded roofs).
Reference Level - The reference level for the roof (enabled only for extruded roofs).
Level Offset - Raises or lowers the roof from the reference level (enabled only for
extruded roofs). -
Tread: The tread is the piece of steel that makes up the steps of the stair. The tread can be made from grating orfrom pans (both shown in Figure 1). Grating is typically used in industrial buildings while pans are usually used in commercial structures. The grating type of tread is plate, but the pan shape dips down so that the concrete can be poured into its base. Sanitary-type pans, which are common in hospitals, have an additional lip that prevents dirt from falling into the corner of the pan.
Stringers: The stringers support the ends of the treads. Stringers are often rectangular hollow sections, channels or plate. The top of the stringer is connected either to a supporting beam or to a dog leg (see Figure 3). The bottom of the stringer is connected to a supporting beam, a dog leg, or the ground. If attached to a supporting beam, the stringer can be bolted or welded. If attached to a dog leg, the stringer will be welded.
Supporting Beam: The supporting beam supports the stringer or the dog leg (if it exists). Each stringer can be independently supported. Alternately, both stringers can be supported with the same supporting beam. The supporting beams are usually wide flange sections or channels.
Dog legs: The location of the supporting beams determines whether dog legs are actually needed. A dog leg is needed when a viable connection cannot be made to the supporting beam directly from the stringer. The dog leg can be the support for the landing at the top of the stair, if one exists.
Special pans: These are required at the top and bottom of a pan stair. One special pan closes the stair against the concrete or platform, and the other pan closes off the top of the stair.
Rise and tread: Although the actual stair step is called the tread, there is also a measurement, as shown in Figure 1, which is termed the 'tread'. This is the horizontal distance between two consecutive treads. The rise is the vertical distance between two consecutive treads.
Rise and tread: Although the actual stair step is called the tread, there is also a measurement, as shown in Figure 1, which is termed the 'tread'. This is the horizontal distance between two consecutive treads. The rise is the vertical distance between two consecutive treads.
Stringer offset value (top of steel of stringer to nosing line): As shown in Figure 6, the stringer offset is the perpendicular distance between the top of steel of the stringer and the nosing line. The stringer offset value is required for locating the stringer in space.
Dog leg to nosing point height: Where dog legs are required (i.e. cases where the stringer can't directly make a viable connection to the supporting beam), it is necessary to locate the dog legs. The top dog leg to nosing point height is the distance from the top nosing point to the top of steel of the top dog leg. The bottom dog leg to nosing point height is the distance from the bottom nosing point to the top of steel of the bottom dog leg.
Number of treads: The number of treads is obtained by dividing the total rise by the safe rise, or alternately by dividing the total run by the safe run.
eccentricity, the distance from the center of gravity of the column section to the center of gravity of the applied load. Eccentricity in this analysis is considered as being parallel to one of the sides of a rectangular column.
In a building, headroom is the clear, vertical height (vertical clearance) which exists from the top surface of a floor to the underside of a:
Ceiling. - Door head,
Door head, - Staircase ceiling.
Staircase ceiling. - Between two floors, the headroom is the clear vertical space between the two decks, from the top of the finished floor level of the lower deck, to the underside of the soffit of the upper deck. Low headroom may increase the likelihood of injury or the difficulty of manoeuvring large objects.
Between two floors, the headroom is the clear vertical space between the two decks, from the top of the finished floor level of the lower deck, to the underside of the soffit of the upper deck. Low headroom may increase the likelihood of injury or the difficulty of manoeuvring large objects.
The headroom may or may not be sufficient to allow people to pass under easily. If not sufficient, it will not be possible to pass through without crouching or striking the top surface.
Rebar Cover Element Properties - Rebar Cover Element Properties
Rebar Cover Element Properties - Revit Structure
Revit Structure - The following table describes cover related parameters in the Structural section of concrete element Properties palettes.
The following table describes cover related parameters in the Structural section of concrete element Properties palettes.
Name - Description
Description - Rebar Cover - Top Face
Rebar Cover - Top Face - The cover settings for the highest face of an element instance.
The cover settings for the highest face of an element instance.
Rebar Cover - Bottom Face - The cover settings for the lowest face of an element instance.
The cover settings for the lowest face of an element instance.
Rebar Cover - Interior Face - Walls only parameter. The cover settings for the interior face of a concrete wall.
Walls only parameter. The cover settings for the interior face of a concrete wall.
Rebar Cover - Exterior Face - Walls only parameter. The cover settings for the exterior face of a concrete wall.
Walls only parameter. The cover settings for the exterior face of a concrete wall.
Rebar Cover - Other Faces - The default cover settings for element instances that do not qualify as highest, lowest, interior, or exterior. This cover setting applies to elements created with openings.
The default cover settings for element instances that do not qualify as highest, lowest, interior, or exterior. This cover setting applies to elements created with openings.
Area Reinforcement Only - Additional Top/Exterior Offset
Additional Top/Exterior Offset - Specifies an additional offset from the top/exterior rebar cover. This allows placing multiple rebar elements together in different area reinforcement layers.
Specifies an additional offset from the top/exterior rebar cover. This allows placing multiple rebar elements together in different area reinforcement layers.
Additional Bottom/Interior Offset - Specifies an additional offset from the bottom/interior rebar cover. This allows placing multiple rebar elements together in different area reinforcement layers.
Specifies an additional offset from the bottom/interior rebar cover. This allows placing multiple rebar elements together in different area reinforcement layers.
Path Reinforcement Only - Additional Offset
Additional Offset - Specifies an additional offset from the rebar cover. This allows placing multiple rebar elements together in different path reinforcement layers.
Specifies an additional offset from the rebar cover. This allows placing multiple rebar elements together in different path reinforcement layers.
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Janet Berry-Johnson is a CPA with 10 years of experience in public accounting and writes about income taxes and small business accounting.
What Is Accounting? - Accounting is the process of recording financial transactions pertaining to a business. The accounting process includes summarizing, analyzing and reporting these transactions to oversight agencies, regulators and tax collection entities. The financial statements used in accounting are a concise summary of financial transactions over an accounting period, summarizing a company's operations, financial position and cash flows.
Accounting is the process of recording financial transactions pertaining to a business. The accounting process includes summarizing, analyzing and reporting these transactions to oversight agencies, regulators and tax collection entities. The financial statements used in accounting are a concise summary of financial transactions over an accounting period, summarizing a company's operations, financial position and cash flows.
1:44 - Accounting
Accounting - How Accounting Works
How Accounting Works - Accounting is one of the key functions for almost any business. It may be handled by a bookkeeper or an accountant at a small firm, or by sizable finance departments with dozens of employees at larger companies. The reports generated by various streams of accounting, such as cost accounting and managerial accounting, are invaluable in helping management make informed business decisions.
Accounting is one of the key functions for almost any business. It may be handled by a bookkeeper or an accountant at a small firm, or by sizable finance departments with dozens of employees at larger companies. The reports generated by various streams of accounting, such as cost accounting and managerial accounting, are invaluable in helping management make informed business decisions.
Key Takeaways - Regardless of the size of a business, accounting is a necessary function for decision making, cost planning, and measurement of economic performance measurement.
Regardless of the size of a business, accounting is a necessary function for decision making, cost planning, and measurement of economic performance measurement.
A bookkeeper can handle basic accounting needs, but a Certified Public Accountant (CPA) should be utilized for larger or more advanced accounting tasks.
Two important types of accounting for businesses are managerial accounting and cost accounting. Managerial accounting helps management teams make business decisions, while cost accounting helps business owners decide how much a product should cost.
Professional accountants follow a set of standards known as the Generally Accepted Accounting Principles (GAAP) when preparing financial statements.
The financial statements that summarize a large company's operations, financial position and cash flows over a particular period are concise and consolidated reports based on thousands of individual financial transactions. As a result, all accounting designations are the culmination of years of study and rigorous examinations combined with a minimum number of years of practical accounting experience.
While basic accounting functions can be handled by a bookkeeper, advanced accounting is typically handled by qualified accountants who possess designations such as Certified Public Accountant (CPA) or Certified Management Accountant (CMA) in the United States. In Canada, the three legacy designationsthe Chartered Accountant (CA), Certified General Accountant (CGA), and Certified Management Accountant (CMA)have been unified under the Chartered Professional Accountant (CPA) designation.
The Alliance for Responsible Professional Licensing (ARPL) was formed during August 2019 in response to a series of state deregulatory proposals making the requirements to become a CPA more lenient. The ARPL is a coalition of various advanced professional groups including engineers, accountants and architects.
Types of Accounting - Financial Accounting
Financial Accounting - Financial accounting refers to the processes used to generate interim and annual financial statements. The results of all financial transactions that occur during an accounting period are summarized into the balance sheet, income statement and cash flow statement. The financial statements of most companies are audited annually by an external CPA firm. For some, such as publicly traded companies, audits are a legal requirement. However, lenders also typically require the results of an external audit annually as part of their debt covenants. Therefore, most companies will have annual audits for one reason or another.
Financial accounting refers to the processes used to generate interim and annual financial statements. The results of all financial transactions that occur during an accounting period are summarized into the balance sheet, income statement and cash flow statement. The financial statements of most companies are audited annually by an external CPA firm. For some, such as publicly traded companies, audits are a legal requirement. However, lenders also typically require the results of an external audit annually as part of their debt covenants. Therefore, most companies will have annual audits for one reason or another.
Managerial Accounting - Managerial accounting uses much of the same data as financial accounting, but it organizes and utilizes information in different ways. Namely, in managerial accounting, an accountant generates monthly or quarterly reports that a business's management team can use to make decisions about how the business operates. Managerial accounting also encompasses many other facets of accounting, including budgeting, forecasting and various financial analysis tools. Essentially, any information that may be useful to management falls underneath this umbrella.
Managerial accounting uses much of the same data as financial accounting, but it organizes and utilizes information in different ways. Namely, in managerial accounting, an accountant generates monthly or quarterly reports that a business's management team can use to make decisions about how the business operates. Managerial accounting also encompasses many other facets of accounting, including budgeting, forecasting and various financial analysis tools. Essentially, any information that may be useful to management falls underneath this umbrella.
Cost Accounting - Just as managerial accounting helps businesses make decisions about management, cost accounting helps businesses make decisions about costing. Essentially, cost accounting considers all of the costs related to producing a product. Analysts, managers, business owners and accountants use this information to determine what their products should cost. In cost accounting, money is cast as an economic factor in production, whereas in financial accounting, money is considered to be a measure of a company's economic performance.
Just as managerial accounting helps businesses make decisions about management, cost accounting helps businesses make decisions about costing. Essentially, cost accounting considers all of the costs related to producing a product. Analysts, managers, business owners and accountants use this information to determine what their products should cost. In cost accounting, money is cast as an economic factor in production, whereas in financial accounting, money is considered to be a measure of a company's economic performance.
Requirements for Accounting - In most cases, accountants use generally accepted accounting principles (GAAP) when preparing financial statements in the U.S. GAAP is a set of standards and principles designed to improve the comparability and consistency of financial reporting across industries. Its standards are based on double-entry accounting, a method in which every accounting transaction is entered as both a debit and credit in two separate general ledger accounts that will roll up into the balance sheet and income statement.
In most cases, accountants use generally accepted accounting principles (GAAP) when preparing financial statements in the U.S. GAAP is a set of standards and principles designed to improve the comparability and consistency of financial reporting across industries. Its standards are based on double-entry accounting, a method in which every accounting transaction is entered as both a debit and credit in two separate general ledger accounts that will roll up into the balance sheet and income statement.
Example of Accounting - To illustrate double-entry accounting, imagine a business sends an invoice to one of its clients. An accountant using the double-entry method records a debit to accounts receivables, which flows through to the balance sheet, and a credit to sales revenue, which flows through to the income statement.
To illustrate double-entry accounting, imagine a business sends an invoice to one of its clients. An accountant using the double-entry method records a debit to accounts receivables, which flows through to the balance sheet, and a credit to sales revenue, which flows through to the income statement.
When the client pays the invoice, the accountant credits accounts receivables and debits cash. Double-entry accounting is also called balancing the books, as all of the accounting entries are balanced against each other. If the entries aren't balanced, the accountant knows there must be a mistake somewhere in the general ledger.
History of Accounting - The history of accounting has been around almost as long as money itself. Accounting history dates back to ancient civilizations in Mesopotamia, Egypt and Babylon. For example, during the Roman Empire the government had detailed records of their finances. However, modern accounting as a profession has only been around since the early 19th century.
The history of accounting has been around almost as long as money itself. Accounting history dates back to ancient civilizations in Mesopotamia, Egypt and Babylon. For example, during the Roman Empire the government had detailed records of their finances. However, modern accounting as a profession has only been around since the early 19th century.
Luca Pacioli is considered "The Father of Accounting and Bookkeeping" due to his contributions to the development of accounting as a profession. An Italian mathematician and friend of Leonardo da Vinci, Pacioli published a book on the double-entry system of bookkeeping in 1494.
By 1880, the modern profession of accounting was fully formed and recognized by the Institute of Chartered Accountants in England and Wales. This institute created many of the systems by which accountants practice today. The formation of the institute occurred in large part due to the Industrial Revolution. Merchants not only needed to track their records but sought to avoid bankruptcy as well.
Frequently Asked Questions - What is accounting?
What is accounting? - Accounting is a profession whose core responsibility is to help businesses maintain accurate and timely records of their finances. Accountants are responsible for maintaining records of a companys daily transactions, and compiling those transactions into financial statements such as the balance sheet, income statement, and statement of cashflows. Accountants also provide other services, such as performing periodic audits or preparing ad-hoc management reports.
Accounting is a profession whose core responsibility is to help businesses maintain accurate and timely records of their finances. Accountants are responsible for maintaining records of a companys daily transactions, and compiling those transactions into financial statements such as the balance sheet, income statement, and statement of cashflows. Accountants also provide other services, such as performing periodic audits or preparing ad-hoc management reports.
What skills are required for accounting? - Accountants hail from a wide variety of backgrounds. Generally speaking, however, attention to detail is a key component in accountancy, since accountants must be able to diagnose and correct subtle errors or discrepancies in a companys accounts. The ability to think logically is also essential, to help with problem-solving. Mathematical skills are helpful, but are less important than in previous generations due to the wide availability of computers and calculators.
Accountants hail from a wide variety of backgrounds. Generally speaking, however, attention to detail is a key component in accountancy, since accountants must be able to diagnose and correct subtle errors or discrepancies in a companys accounts. The ability to think logically is also essential, to help with problem-solving. Mathematical skills are helpful, but are less important than in previous generations due to the wide availability of computers and calculators.
Why is accounting important for investors? - The work performed by accountants is at the heart of modern financial markets. Without accounting, investors would be unable to rely on timely or accurate financial information, and companies managements would lack the transparency needed to manage risks or plan projects. Regulators also rely on accountants for critical functions such as providing auditors opinions on companies annual 10-K filings. In short, although accounting is sometimes overlooked, it is absolutely critical for the smooth functioning of modern finance.
The work performed by accountants is at the heart of modern financial markets. Without accounting, investors would be unable to rely on timely or accurate financial information, and companies managements would lack the transparency needed to manage risks or plan projects. Regulators also rely on accountants for critical functions such as providing auditors opinions on companies annual 10-K filings. In short, although accounting is sometimes overlooked, it is absolutely critical for the smooth functioning of modern finance.
Article Sources - Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
American Institute of Certified Public Accountants. "CPA Licensure." Accessed Aug. 6, 2020.
The Institute of Chartered Accountants in England and Wales. "Timeline: 1853-1880." Accessed Aug. 6, 2020.
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Provider - Name
Name - Description
Description - Related Terms
Related Terms - A general ledger is the record-keeping system for a companys financial data, with debit and credit account records validated by a trial balance.
A general ledger is the record-keeping system for a companys financial data, with debit and credit account records validated by a trial balance.
Administrative accounting handles and reports internal factors and figures that influence decision making, operational control and managerial planning.
Reconciliation is an accounting process that compares two sets of records to check that figures are correct, and can be used for personal or business reconciliations.
Financial accounting is the process of recording, summarizing and reporting the myriad of a company's transactions to provide an accurate picture of its financial position.
Micro accounting is accounting at a personal, corporate or government level, and is the opposite of macro accounting.
Managerial accounting is the practice of analyzing and communicating financial data to managers, who use the information to make business decisions.
A construction guarantee is just like a letter of credit
14th August 2009 - Major construction works are currently under way in various cities and towns across South Africa. Most of the contracts governing these works require the contractor to provide a construction guarantee to the owner (or employer) guaranteeing the contractors performance undertaken in terms of the construction contract, or principal building agreement (PBA). Construction guarantees are used to indemnify the employer against damages suffered in the event of the contractors default under the PBA.
Major construction works are currently under way in various cities and towns across South Africa. Most of the contracts governing these works require the contractor to provide a construction guarantee to the owner (or employer) guaranteeing the contractors performance undertaken in terms of the construction contract, or principal building agreement (PBA). Construction guarantees are used to indemnify the employer against damages suffered in the event of the contractors default under the PBA.
Various short-term insurance com- panies (or guarantors) are issuing construction guarantees on behalf of contractors to provide a benefit to employers upon the occurrence of certain eventualities relating to the failure of the contractor to perform its obligations under the PBA. The Short-Term Insurance Act defines a guarantee policy as a contract in terms of which a person, other than a bank, in return for a premium, undertakes to provide benefits if an event, contemplated in the policy as a risk relating to the failure of a person to discharge an obligation, occurs.
In a number of recent cases, the respondents endeavoured, unsuccessfully, to go behind the provisions of the guarantee with a view to finding reasons in the PBA why the guarantee should not be paid.
The purpose of a construction guarantee is to create a primary obligation on the guarantor to make payment upon the occurrence of a certain event, and the obligation may be equated to an indemnity. In this event, the construction guarantee will operate independently of the PBA.
This is illustrated in the recent matter of the Johannesburg Development Agency (JDA) versus Federated Insurance Guarantees Brokers. The applicant, the JDA, concluded a PBA, in the form of a standard JBCC Series 2000 contract, with a contractor. The respondent, Federated, issued a variable construction guarantee in favour of the applicant at the instance of the contractor. The applicant subsequently called upon the respon- dent to make payment in accordance with the guarantee as a result of the contractors default under the PBA. Despite compliance with the terms of the guarantee calling for payment, the respondent failed to make payment, and the applicant instituted proceedings in the High Court. The respondent contended that the applicant had been in breach of its obligations under the PBA and that its tardy payment of the amounts properly due to the contractor had precipitated the contractors inability to perform the work properly.
The court found in favour of the applicant and stated: The guarantee alone generates liability, and . . . the guarantee constitutes a principal obligation and not one ancillary to the contractors obligations in terms of the contract.
On appeal by the respondent, the Appeal Court upheld the principle enunciated by the High Court (albeit three years after the matter had been instituted) and confirmed that the respondent was liable under the guaran- tee, irrespective of the allegation that the applicant had been in default of the terms of the PBA. A further application by the respondent for special leave to appeal to the Supreme Court of Appeal failed.
In a recent decision by the Supreme Court of Appeal, the court came to the same conclusion when considering the terms of a construction guarantee similar to that issued by Federated Insurance Guarantees Brokers.
In summary, the facts were that the appellant had issued a construction guarantee on behalf of a contractor in favour of the employer. The first respondent executed an indemnity in favour of the appellant in terms of which the first respondent undertook to indemnify (and keep indemnified) the appellant from and against all loss which the appellant may sustain by reason of it issuing the construction guarantee on behalf of the contractor. The employer called the guarantee and the appellant made payment in terms of the construction guarantee. It emerged that the principal agent had perpetrated a fraud, with the consequence, so it was alleged, that neither the appellant nor the respondents were liable for payment. The court found that the appellant had not colluded in the fraud perpetrated by the principal agent and decided the matter on the basis that the guarantee must be interpreted in conjunction with the PBA.
On appeal, the Supreme Court of Appeal held that the guarantee creates an obligation to pay upon the happening of an event [and that] the guarantee itself records that reference to the construction contract is solely for the purpose of convenience and there is no intention to create an accessory obligation or suretyship.
The peculiar feature of this case is that, upon discovering the fraud alleged to have been perpetrated by the principal agent, the appellant could, presumably, have recovered the payment made to the employer. If this was so, why should the first respondent have been obliged to pay under the indemnity?
Nevertheless, these decisions illustrate the fact that construction guarantees are not unlike irrevocable letters of credit issued by commercial banks in the context of international trade. The essential feature of a letter of credit is the placing of a contractual obligation on the bank to pay the beneficiary upon presentation of documents, provided that the conditions specified in the letter of credit are fulfilled. The only basis upon which a bank can escape liability is to prove a fraud on the part of the beneficiary, that is, where the beneficiary, for the purpose of drawing down on the letter of credit, fraudulently presents to the bank documents that, to the beneficiarys knowledge, misrepresent the material facts. It follows that liability under a guarantee can also be avoided in cases of fraud on the part of the beneficiary.
The cases referred to above reiterate the principle that a construction guaran- tee, creating a principal obligation to pay, must be interpreted independently of the PBA. It follows that neither party to a construction guarantee should be entitled to raise issues arising out of the PBA as a defence to a claim made under the construction guarantee in the absence of an express provision to the contrary. The guarantor is bound by his autonomous, unconditional contract and the requirement of strict performance. The guarantor is, therefore, not affected by the terms and conditions of the underlying PBA.
Since a construction guarantee forms an integral part of the construction documents underlying a construction project, it should not be automatically concluded that it must be interpreted with reference to the PBA. Drafting and interpreting construction guarantees remain a complex area of our law. Employers and guarantors, in the context of the construction industry, should, therefore, be mindful of the terms and conditions of the construction guarantee in order to ascertain whether the guarantee intends to create a principal obligation or an accessory obligation to the PBA, as failure to do so will almost inevitably result in complex litigation.
The good news is that the Supreme Court of Appeal has enshrined the concept that a guarantee payable on demand is just that and that there is no right to go behind the provisions of the guarantee with a view to finding reasons for nonpayment of that guarantee based on arguments arising out of the PBA. The bad news is that an unscrupulous respondent can use the judicial system to delay payment for years. When the application for leave to appeal by Federated was dismissed with costs three years after the commencement of motion proceedings in the Durban and Coast Local Division, Federateds attorneys wrote to the JDAs attorneys as follows: We have taken instructions from our client with regard to your letter of 10th April 2009 [demanding payment under the guarantee]. We have been requested to convey to you that our client has fallen victim to the current economic meltdown and is not currently possessed of any resources from which to meet your clients claim.
New Sustainable and Aesthetic Options in Finishing Borders (Wall Base)
Select the best solution to conceal the gap between the wall and floor
December 2013 - Sponsored by: Tarkett
Sponsored by: Tarkett - Jeanette Fitzgerald Pitts
Jeanette Fitzgerald Pitts - Continuing Education
Continuing Education - Use the following learning objectives to focus your study while reading this months Continuing Education article.
Use the following learning objectives to focus your study while reading this months Continuing Education article.
Learning Objectives - After reading this article, you will be able to:
Explain the difference between toe and toeless styles of wall base and identify the applications for which each is best suited.
Compare popular wall base materials in terms of performance, sustainability and cost.
Consider new bio-based and wood alternative wall base solutions for healthcare and commercial applications.
Specify the wall base that best meets the aesthetic, performance and sustainability demands of the project.
Finishing borders, also referred to as wall base, are the architects solution for concealing the gap between the wall and the floor in the built environment. This building component provides the finishing touch to a space as well as general protection from the open exposure between the drywall and the floorboards.
In the past, designers have chosen the right wall base for a project based on the color, style, material and cost. Now, as the design community and building owners become more invested in the idea of green building and sustainable design, designers want the ability to evaluate wall base solutions on the basis of the products overall sustainability as well.
Today, designers can select a wall base that will provide the desired aesthetic, perform as needed, meet budgetary demands, and contribute toward the projects sustainability objectives and it can make this contribution throughout a building, wherever the walls meet the floor.
The Basics for Selecting a Wall Base - Traditionally, when a designer selects a wall base for a project, the material, shape (style), size, performance and price point are all considered.
Traditionally, when a designer selects a wall base for a project, the material, shape (style), size, performance and price point are all considered.
Materials - Wall base is available in a variety of materials, including, wood, steel, carpet, rubber and vinyl. Today, wall base made of rubber and vinyl, often referred to as resilient wall base, can offer specifiers a less expensive wall base solution that is without the issues of durability, fit, and maintenance commonly experienced when wood, steel, or carpet wall base is selected for a job.
Wall base is available in a variety of materials, including, wood, steel, carpet, rubber and vinyl. Today, wall base made of rubber and vinyl, often referred to as resilient wall base, can offer specifiers a less expensive wall base solution that is without the issues of durability, fit, and maintenance commonly experienced when wood, steel, or carpet wall base is selected for a job.
New sustainable and aesthetic wall base solutions offer designers more options for concealing the gap between the wall and the floor.
Photo courtesy of Tarkett - Performance Considerations
Performance Considerations - Wall base adds an important finishing touch to a space, making it feel and look complete. Selecting a wall base that will maintain its aesthetic appeal with minimal maintenance is a typical performance objective. However, not every wall base material is capable of being a virtually maintenance-free, aesthetically uncompromised wall base over time. Wood naturally swells and shrinks in response to changes in temperature and humidity. This shape shifting often causes a wood wall base to separate from the wall. It can also cause the paint coating on the wood to chip, crack and peel and require that the wall base be repainted to restore the aesthetic appeal. In terms of withstanding wear and tear, wood may be one of the least durable wall base materials available, as ordinary use may create dents and dings in the physical wood. Once the physical wood is damaged, it may need to be replaced, instead of repainted, to restore the aesthetic. Carpet can fray over time and keeping the fabric clean and stain-free can present more of a maintenance challenge than may have been considered when the material was initially specified.
Wall base adds an important finishing touch to a space, making it feel and look complete. Selecting a wall base that will maintain its aesthetic appeal with minimal maintenance is a typical performance objective. However, not every wall base material is capable of being a virtually maintenance-free, aesthetically uncompromised wall base over time. Wood naturally swells and shrinks in response to changes in temperature and humidity. This shape shifting often causes a wood wall base to separate from the wall. It can also cause the paint coating on the wood to chip, crack and peel and require that the wall base be repainted to restore the aesthetic appeal. In terms of withstanding wear and tear, wood may be one of the least durable wall base materials available, as ordinary use may create dents and dings in the physical wood. Once the physical wood is damaged, it may need to be replaced, instead of repainted, to restore the aesthetic. Carpet can fray over time and keeping the fabric clean and stain-free can present more of a maintenance challenge than may have been considered when the material was initially specified.
Good fit is another important objective of a wall base. Stainless steel is very low maintenance, and very durable, but the material itself is not very forgiving and this can limit the ability of a stainless steel wall base to adapt to any inconsistencies that may exist in the built space and may compromise the overall fit that it may provide once installed.
Resilient wall base, made of rubber or vinyl, is a low maintenance wall base that resists scuffing, fading and cracking. It addition to its impressive durability, resilient wall base will not shrink or separate from the wall. Traditional resilient wall base is not painted, so it will never need to be repainted, and it is a surface that is easy to clean and disinfect. It is also more flexible and forgiving than other materials, so it can easily accommodate imperfections in the built environment and it is just as easily installed along a straight wall or a circular column.
Resilient wall base is flexible and easily wraps around circular columns.
Photo courtesy of Tarkett - Style
Style - A common question designers have about wall base products relates to the difference between the styles. In the world of wall base, there are many names for essentially two styles. One style of wall base is referred to as flat, straight, or toeless. This straight or toeless style of wall base runs straight from the top of the wall base to the bottom, without any type of sculptured or indentation detail. This style of wall base is best suited to applications with carpet. The other style of wall base is often called toe or cove. This wall base style, as the name may indicate, has a toe at the bottom of the wall base that curves outward to cover the gap. The toe or cove wall base style is best matched to vinyl, rubber, wood or tile floors.
A common question designers have about wall base products relates to the difference between the styles. In the world of wall base, there are many names for essentially two styles. One style of wall base is referred to as flat, straight, or toeless. This straight or toeless style of wall base runs straight from the top of the wall base to the bottom, without any type of sculptured or indentation detail. This style of wall base is best suited to applications with carpet. The other style of wall base is often called toe or cove. This wall base style, as the name may indicate, has a toe at the bottom of the wall base that curves outward to cover the gap. The toe or cove wall base style is best matched to vinyl, rubber, wood or tile floors.
While flat wall base runs straight to the floor, wall base with toe curves outward at the bottom of the border.
Photo courtesy of Tarkett - Size
Size - Across the industry, wall base is typically available in three standard heights and two thicknesses. The three standard heights are 2.5 (6.4cm), 4.0 (10.2cm), 6.0 (15.3cm). Selecting the height of a wall base is, in many applications, almost an exclusively aesthetic decision. One exception is healthcare institutions, where many designers prefer to specify wall base that is 6.0 or higher to offer a greater degree of wall protection.
Across the industry, wall base is typically available in three standard heights and two thicknesses. The three standard heights are 2.5 (6.4cm), 4.0 (10.2cm), 6.0 (15.3cm). Selecting the height of a wall base is, in many applications, almost an exclusively aesthetic decision. One exception is healthcare institutions, where many designers prefer to specify wall base that is 6.0 or higher to offer a greater degree of wall protection.
The two thicknesses are 1/8-inch (3.2mm) and 0.080-inch (2.0mm). The 1/8-inch thickness offers better coverage for camouflaging wall inconsistencies. The 0.080 thickness is a value option, which usually has a lower material cost, but doesnt cover issues in the built environment well. The thinner wall base is often found in tenant improvement situations where cost is the primary consideration.
Cost - While product costs vary from manufacturer to manufacturer, generally speaking, stainless steel wall base is the most expensive. Wood and carpet wall base are less expensive than stainless steel, while resilient wall bases, made from rubber and vinyl, are often the least expensive of the bunch.
While product costs vary from manufacturer to manufacturer, generally speaking, stainless steel wall base is the most expensive. Wood and carpet wall base are less expensive than stainless steel, while resilient wall bases, made from rubber and vinyl, are often the least expensive of the bunch.
Three Types of Resilient Wall Base - Resilient wall base offers specifiers a unique blend of durability, flexibility, and cost effectiveness. The overwhelming advantages of these resilient wall base solutions may explain why resilient wall base is so commonly found throughout commercial, institutional, and healthcare buildings today. However, there are different types of resilient wall base. In order to specify the right resilient wall base throughout a project, it is important to understand the three different materials most commonly used in resilient wall base, how these materials are different, perform differently and possess different sustainable attributes.
Resilient wall base offers specifiers a unique blend of durability, flexibility, and cost effectiveness. The overwhelming advantages of these resilient wall base solutions may explain why resilient wall base is so commonly found throughout commercial, institutional, and healthcare buildings today. However, there are different types of resilient wall base. In order to specify the right resilient wall base throughout a project, it is important to understand the three different materials most commonly used in resilient wall base, how these materials are different, perform differently and possess different sustainable attributes.
There are three materials commonly used to create resilient wall base throughout the industry. They are thermoplastic vinyl (TV), thermoplastic rubber (TP) and thermoset rubber (TS).
Thermoplastic Vinyl (TV) - Thermoplastic vinyl (TV) is a composite of polyvinyl chloride (PVC) and is thermoplastic, which is a polymer that becomes pliable at high temperatures. This material is often used in the construction industry as electrical insulation, tubing, and even upholstery. Of the three materials often used to create resilient wall base, TV is the least expensive. TV will repeatedly soften when heated and stiffen when cooled and after being heated and cooled many times, the material only exhibits a slight loss of its original characteristics.
Thermoplastic vinyl (TV) is a composite of polyvinyl chloride (PVC) and is thermoplastic, which is a polymer that becomes pliable at high temperatures. This material is often used in the construction industry as electrical insulation, tubing, and even upholstery. Of the three materials often used to create resilient wall base, TV is the least expensive. TV will repeatedly soften when heated and stiffen when cooled and after being heated and cooled many times, the material only exhibits a slight loss of its original characteristics.
Thermoplastic Rubber (TP) - Thermoplastic rubber (TP) is a synthetic rubber compound that may or may not contain vinyl, and does not require chemical vulcanization, a process of treating rubber to improve its elasticity and strength. TP will repeatedly soften when heated and stiffen when cooled and after being heated and cooled many times, the material only exhibits a slight loss of its original characteristics.
Thermoplastic rubber (TP) is a synthetic rubber compound that may or may not contain vinyl, and does not require chemical vulcanization, a process of treating rubber to improve its elasticity and strength. TP will repeatedly soften when heated and stiffen when cooled and after being heated and cooled many times, the material only exhibits a slight loss of its original characteristics.
Thermoset Rubber (TS) - Thermoset rubber (TS) is the original resilient wall base material. It is made of natural and/or synthetic rubber and it is the wall base material that is often specified by default when architects use legacy specifications. This material does undergo a chemical vulcanization.
Thermoset rubber (TS) is the original resilient wall base material. It is made of natural and/or synthetic rubber and it is the wall base material that is often specified by default when architects use legacy specifications. This material does undergo a chemical vulcanization.
Compare the Performance of TV, TP, TS
The American Society for Testing and Materials (ASTM) wrote a performance specification for resilient wall base titled the ASTM 1861 Standard Specification for Resilient Wall Base (ASTM F1861). The specification details dimensional and performance requirements that include color stability, flexibility and chemical resistance. In the ASTM performance specification, all three materials TV, TP, and TS are identified as acceptable, with no differentiating statements on where certain materials are better suited.
The ASTM performance specification for resilient wall base recognizes TV, TP, and TS wall base materials as acceptable.
Photo courtesy of Tarkett - Wall base made from TV, TP and TS are similar in many ways. All of the materials give the wall base the flexibility to conform to variations in the wall or floor surface. They offer excellent chemical resistance and great color stability. They also meet the ASTM F1861 dimensional and performance standards as outlined.
Wall base made from TV, TP and TS are similar in many ways. All of the materials give the wall base the flexibility to conform to variations in the wall or floor surface. They offer excellent chemical resistance and great color stability. They also meet the ASTM F1861 dimensional and performance standards as outlined.
But TV, TP and TS are different materials that do, in fact, perform differently. Some of the differences are aesthetic. For example, the TS surface provides a predominately matte finish, while the TP wall base offers a surface that is smooth and consistent. Some of the differences are much more critical. For example, different types and brands of wall base can perform dramatically differently when the room is filled with fire and smoke.
Fire Resistance / Fire Rating The fire resistance/Class rating required for wall base used in certain applications is determined by a number of factors, including, but not limited to:
The version of the International Building Code (IBC) that has been adopted by the state in which the job is being done. Across the United States, different states have adopted different versions of the IBC.
Any local codes which exceed or supercede the requirements of the IBC.
The height of the wall base being specified. Depending on the height, a different test may be required, i.e. critical radiant flux, versus flame spread index.
The area of the building in which the wall base is being installed. Typically, emergency exit ways have a more stringent requirement for fire resistance than does a conference room which has sprinklers.
For example: - The state of Maryland, has adopted the 2012 IBC. The 2012 IBC requires that interior floor-wall base that is 6 inches or less in height shall be tested for critical radiant flux in accordance with NFPA 253 (ASTM E-648), and the rating shall not be less than Class II. Where a Class I floor finish is required, the floor-wall base shall be a Class I (highest).
The state of Maryland, has adopted the 2012 IBC. The 2012 IBC requires that interior floor-wall base that is 6 inches or less in height shall be tested for critical radiant flux in accordance with NFPA 253 (ASTM E-648), and the rating shall not be less than Class II. Where a Class I floor finish is required, the floor-wall base shall be a Class I (highest).
For floor-wall base that is over 6 inches in height, but less than 10% of the specific wall area, the 2012 IBC requires that it is treated as interior trim, which has a minimum Class C flame spread and smoke developed index when tested in accordance with ASTM E-84 (UL 723).
New York City has its own building code which supercedes the 2006 IBC which has been adopted by the state of New York. The NYC building code has a much more stringent requirement for flame spread & smoke developed index for emergency exit ways than even the latest version of the IBC.
This is not intended to be a comprehensive discussion of fire resistance/fire rating for wall base, but simply a demonstration of how many different factors come into play when selecting a wall base to meet the requirements. It is very important, for each project, to know what codes apply to that location and which products meet those requirements. Each manufacturer publishes the Class ratings for each of their resilient wall base products. Keep in mind that even within each type of wall base (TV, TP & TS), different manufacturers may have a different Class rating.
Considering Sustainability - Beyond building codes and budgets, the overall sustainability of a product is another consideration that more and more designers are becoming inclined to make before specifying any material. Evaluating the sustainable nature of a product requires a review of not only its material contents, but also its manufacturing processes and whether the product is ultimately reused or recycled.
Beyond building codes and budgets, the overall sustainability of a product is another consideration that more and more designers are becoming inclined to make before specifying any material. Evaluating the sustainable nature of a product requires a review of not only its material contents, but also its manufacturing processes and whether the product is ultimately reused or recycled.
Identifying the criteria that will be used to evaluate the sustainability of a product lays the foundation for being able to compare the sustainability of one product with another. These criteria can vary from designer to designer and, even, from project to project within a designers portfolio, depending upon the type of project, project objectives, and unique client preferences. In this article, the sustainable nature of various wall base solutions will be evaluated on the basis of the type of material used for the wall base, the environmental impact of the manufacturing processes employed to create the wall base, and whether or not it is possible to reuse or recycle the product.
Selecting More Sustainable Materials - The term sustainable material refers to a material that is generated from a resource that is managed in a way or replenished with a frequency, where it is considered, for all practical purposes, to be available into and beyond the foreseeable future. On the continuum between rapidly renewable resources and non-renewable resources, the more readily renewable the resource, the more sustainable the material is considered to be. A rapidly renewable resource is defined as being plant-based and having a harvest cycle of 10 years or less. Examples of rapidly renewable resources include bamboo, agrifiber, cotton, and natural rubber, a material used in certain types of resilient wall base.
The term sustainable material refers to a material that is generated from a resource that is managed in a way or replenished with a frequency, where it is considered, for all practical purposes, to be available into and beyond the foreseeable future. On the continuum between rapidly renewable resources and non-renewable resources, the more readily renewable the resource, the more sustainable the material is considered to be. A rapidly renewable resource is defined as being plant-based and having a harvest cycle of 10 years or less. Examples of rapidly renewable resources include bamboo, agrifiber, cotton, and natural rubber, a material used in certain types of resilient wall base.
Certain types of resilient wall base are made from natural rubber, a rapidly renewable resource.
Photo courtesy of Tarkett - Products containing recycled materials can also offer a more sustainable product solution. Specifying products that contain recycled materials actively diverts materials from the waste stream, and the landfill, for recycling and reuse. Resilient wall base that contains some level of recycled content is also now available on the market.
Products containing recycled materials can also offer a more sustainable product solution. Specifying products that contain recycled materials actively diverts materials from the waste stream, and the landfill, for recycling and reuse. Resilient wall base that contains some level of recycled content is also now available on the market.
Comparing the Materials in TV, TP, TS Wall Base As previously mentioned, TV, TP and TS are three different types of resilient wall base manufactured from three different material blends. These various material blends can have different sustainable properties. For example, TV wall base can contain recycled content, while TS wall base can contain different amounts of natural rubber, a rapidly renewable resource.
Selecting Non-Toxic Materials - A material can continue to impact an environment, even after it is removed from the ground. Some materials release a gas into the interior environment, after they have been processed and installed, a phenomenon called off-gassing. Look for wall bases that have low volatile organic compound (VOC) emissions and meet the requirements of CA01350 to ensure good indoor air quality, which affects the wellbeing and health of people in spaces.
A material can continue to impact an environment, even after it is removed from the ground. Some materials release a gas into the interior environment, after they have been processed and installed, a phenomenon called off-gassing. Look for wall bases that have low volatile organic compound (VOC) emissions and meet the requirements of CA01350 to ensure good indoor air quality, which affects the wellbeing and health of people in spaces.
Phthalates and polyvinyl chloride (PVC) are often used in manufacturing resilient wall base to improve the flexibility and durability of the product. Some manufacturers have changed their plasticizers for phthalate alternatives making them safe solutions to use in interior spaces. Concerns have been raised about the impact that phthalates can have on the air quality of the interior environment and the health of building occupants. It is important for the specifier to use low emitting wall base and consider products that are made with alternative types of plasticizers.
There is a new pilot credit in LEED 2009 that promotes chemicals of concern avoidance. This new pilot credit, entitled Avoidance of Chemicals of Concern, is pilot credit 54 in the Materials and Resources category (MRpc54) and it was written with the intent of reducing the concentration of chemical contaminants that can damage air quality, human health, productivity, and the environment. This pilot credit was closed to new registrations on February 15, 2013. Projects that registered for the credit prior to February 15, 2013 can continue to pursue it.
It should be noted that there is some controversy that surrounds the opinion that the presence of phthalates and PVC reduces the overall sustainability of a product. While one side points to the adverse health effects that these products may contribute, others cite the increased longevity that the use of PVC and phthalates can provide, which dramatically reduces the total amount of product that will be placed in a landfill every year. All PVCs are not made equal; some made with phthalate alternatives and low emissions are sustainable products to use in interiors. Specifiers will need to consider the unique needs and objectives of each individual project to identify whether the presence or absence of phthalates or PVC is in its best interest.
Phthalates and PVC in TV, TP, and TS Depending upon the needs of the project, there is a resilient wall base that will offer a specifier the right presence of phthalates and PVC. TV contains PVC and is available in products that do and do not contain phthalates. Wall base made from TP may or may not contain PVC and may or may not contain phthalates. Wall base made from TS is both phthalate-free and PVC-free.
Efficient Manufacturing Processes - The efficiency of a manufacturing process relates to both the energy consumed for the manufacturing process and the waste created during the process. More efficient processes consume less energy and create less waste.
The efficiency of a manufacturing process relates to both the energy consumed for the manufacturing process and the waste created during the process. More efficient processes consume less energy and create less waste.
The Differences in Manufacturing TV, TP, TS Wall base made from thermoplastic materials, which include both TV and TP wall base, are manufactured by heating the thermoplastic material until it melts and then shaping it and cooling it to give it its desired shape. Thermoset products, like TS wall base, undergo a chemical process that changes the molecular structure of the material and cures it into its shape.
When comparing the energy consumption of the two processes, it takes more energy to heat a material enough to change it at a molecular level than it does to simply change its shape. So it follows that it takes more energy to manufacture a wall base made from TS than one made from a thermoplastic blend like TV or TP.
There are certain aspects of the wall base production process that directly affect the amount of waste that can be produced. The use of dye lots in a product is one such aspect. If dye lots are not used during production, the amount of waste and scrap material produced is reduced throughout the supply chain.
Recycle Wall Base - Specifying wall base that can be recycled makes it possible to divert these materials from the landfill, once its time as wall base is over, and repurpose them to be used again and again.
Specifying wall base that can be recycled makes it possible to divert these materials from the landfill, once its time as wall base is over, and repurpose them to be used again and again.
Recycling TV, TP, TS Thermoplastic wall base, like TV and TP wall base, can be ground up and reprocessed, allowing it to be recycled in a wide variety of ways. Thermoset materials, like TS wall base, are more limited in the ways that it can be recycled; because the chemical curing process that gives the TS wall base its initial form changes the material at a molecular level and makes it impossible to reshape it. When reheated, thermoset materials will decompose before melting, so TS wall base can be ground up and used as filler in other products, such as playgrounds, or mulch, but it cannot be melted down and reshaped.
Although all compliant with ASTM performance requirements, TS, TP, and TV wall base do appear different, perform differently, and embody different sustainable characteristics.
Photo courtesy of Tarkett - New Bio-Based Wall Base
New Bio-Based Wall Base - Technological advancements and material innovation now make it possible for designers to specify a new bio-based wall base that offers sustainable characteristics that are far beyond anything available in the more traditional TV, TP and TS materials, without sacrificing performance. This more sustainable wall base solution meets all of the performance requirements of the ASTM-F1861, Standard Specification for Resilient Wall Base.
Technological advancements and material innovation now make it possible for designers to specify a new bio-based wall base that offers sustainable characteristics that are far beyond anything available in the more traditional TV, TP and TS materials, without sacrificing performance. This more sustainable wall base solution meets all of the performance requirements of the ASTM-F1861, Standard Specification for Resilient Wall Base.
New bio-based wall base contains rapidly renewable resources that include: walnut shells, pine rosin, and vegetable oil.
Photo courtesy of Tarkett - This new bio-based wall base contains rapidly renewable materials that include walnut shells, pine rosin and vegetable oil. Even the fillers in this bio-based solution are natural materials like walnut shells and oyster shells. The sustainable nature of this product enables it to be used to contribute toward earning LEED points in the satisfaction of the LEED MR credit 6 (MRc6) entitled 5 Percent Rapidly Renewable Content.
This new bio-based wall base contains rapidly renewable materials that include walnut shells, pine rosin and vegetable oil. Even the fillers in this bio-based solution are natural materials like walnut shells and oyster shells. The sustainable nature of this product enables it to be used to contribute toward earning LEED points in the satisfaction of the LEED MR credit 6 (MRc6) entitled 5 Percent Rapidly Renewable Content.
Beyond containing more readily renewable materials, the bio-based wall base is phthalate-free and PVC-free, like TS wall base, but is manufactured in a more energy efficient process than the chemical curing that TS requires. These materials can also be reprocessed and repurposed into a wide variety of products.
New Options for a Wood Wall Base - Designers are looking for more than sustainable wall base solutions. New wall base products are emerging to support the current trend in healthcare settings where institutions are being designed to convey a more residential look and feel. Designers are increasingly incorporating more wood and wood-aesthetic throughout a space. Now resilient wall base products are available in a wood finish that will achieve the warmer, residential appearance, without opening the space to the performance issues, like cracking or separating from the wall, commonly experienced with traditional wood wall base.
Designers are looking for more than sustainable wall base solutions. New wall base products are emerging to support the current trend in healthcare settings where institutions are being designed to convey a more residential look and feel. Designers are increasingly incorporating more wood and wood-aesthetic throughout a space. Now resilient wall base products are available in a wood finish that will achieve the warmer, residential appearance, without opening the space to the performance issues, like cracking or separating from the wall, commonly experienced with traditional wood wall base.
New wood finish resilient wall base products offer the warmth and aesthetic appeal of wood in a solution that is resistant to cracks and scuffing and able to withstand rigorous cleaning and harsh disinfectants.
Photo courtesy of Tarkett - The selection of resilient wall base designed to offer a wood aesthetic continues to grow and there are more profiles, more colors, and more finishes available than ever before. The straight and toe styles of resilient wall base can be selected in a variety of wood grain finishes. There is even a resilient wall base product with a profile that resembles a piece of wood that has been milled. Instead of a flat, straight wall base, these wall base products incorporate a contour that mirrors the shape often found in real wood molding.
The selection of resilient wall base designed to offer a wood aesthetic continues to grow and there are more profiles, more colors, and more finishes available than ever before. The straight and toe styles of resilient wall base can be selected in a variety of wood grain finishes. There is even a resilient wall base product with a profile that resembles a piece of wood that has been milled. Instead of a flat, straight wall base, these wall base products incorporate a contour that mirrors the shape often found in real wood molding.
This contoured resilient wall base offers a heightened wood aesthetic in a solution that is resistant to scuffing, fading and cracking. In addition, these wall base solutions are free of knots and nail-heads and they will not splinter, chip or absorb liquids. These products are a great option for healthcare settings as they provide the residential look and feel, while being able to withstand the harsh disinfectants and more rigorous cleaning regimens employed in a healthcare facility.
Wall Base Creates Visual Interest - Now resilient wall base can be used to create visual interest in a space as well. High-definition, digital imaging technology prints directly on the surface of the wall base. Specifiers can select wood grains like rosewood, zebrawood, cherry, maple, and mahogany or stone looks that mimic travertine, veined marble, sandstone, limestone and others.
Now resilient wall base can be used to create visual interest in a space as well. High-definition, digital imaging technology prints directly on the surface of the wall base. Specifiers can select wood grains like rosewood, zebrawood, cherry, maple, and mahogany or stone looks that mimic travertine, veined marble, sandstone, limestone and others.
Create visual interest with wall base by specifying a high definition print that can mimic exotic materials, patterns, or images.
Photo courtesy of Tarkett - Beyond those standard digital finishes, advanced digital imaging technology makes possible to customize a wall base with virtually any visual image. Designers can choose any exotic wood grain, rock pattern, floral print, abstract pattern, or custom match the fabric in a wall covering or office chair.
Beyond those standard digital finishes, advanced digital imaging technology makes possible to customize a wall base with virtually any visual image. Designers can choose any exotic wood grain, rock pattern, floral print, abstract pattern, or custom match the fabric in a wall covering or office chair.
In the end, with all of these advancements in wall base, from being manufactured from more sustainable materials, to offering a more durable wood aesthetic, to being able to be digitally printed with any pattern or color imaginable, one thing is for sure: designing for the gap between the wall and the floor is now a lot more interesting.
For more than 100 years, Johnsonite has been a leading provider of innovative flooring solutions that integrate function, design, life safety and sustainability to enhance productivity in commercial spaces. Johnsonite is the North American commercial brand of the Tarkett Group. http://www.johnsonite.com
at - preposition
preposition - (used to indicate a point or place occupied in space); in, on, or near: to stand at the door; at the bottom of the barrel.
(used to indicate a point or place occupied in space); in, on, or near: to stand at the door; at the bottom of the barrel.
(used to indicate a location or position, as in time, on a scale, or in order): at zero; at noon; at age 65; at the end; at the lowest point.
(used to indicate presence or location): at home; at hand.
(used to indicate amount, degree, or rate): at great speed; at high altitudes.
(used to indicate a direction, goal, or objective); toward: Aim at the mark. Look at that.
(used to indicate occupation or involvement): at work; at play.
(used to indicate a state or condition): at ease; at peace.
(used to indicate a cause or source): She was annoyed at his stupidity.
(used to indicate a method or manner): He spoke at length.
(used to indicate relative quality or value): at one's best; at cost.
SEE MORESEE LESS - QUIZZES
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Idioms for at
Idioms for at - be at (someone), to be sexually aggressive toward (a person): She's pregnant again because he's at her morning, noon, and night.
be at (someone), to be sexually aggressive toward (a person): She's pregnant again because he's at her morning, noon, and night.
where it's at, Informal. the place where the most interesting or exciting things happen: Emma says that Rome is definitely where it's at now.
Origin of at - 1
1 - First recorded before 900; Middle English; Old English t; cognate with Old Frisian et, Old Norse, Old Saxon, Gothic at, Old High German az, Latin, Old Welsh, Old Breton ad, Oscan ad-, Umbrian a-, Old Irish, Gaulish, Phrygian ad-
First recorded before 900; Middle English; Old English t; cognate with Old Frisian et, Old Norse, Old Saxon, Gothic at, Old High German az, Latin, Old Welsh, Old Breton ad, Oscan ad-, Umbrian a-, Old Irish, Gaulish, Phrygian ad-
Words nearby at - Definition for at (2 of 9)
Definition for at (2 of 9) - or att
or att - noun, plural at or ats.
noun, plural at or ats. - a money of account of Laos, one 100th of a kip.
a money of account of Laos, one 100th of a kip.
Origin of at - 2
2 - First recorded in 195055; from Lao; compare Thai t formerly, a copper coin worth one eighth of a fang, ultimately from Pali aha eight
First recorded in 195055; from Lao; compare Thai t formerly, a copper coin worth one eighth of a fang, ultimately from Pali aha eight
Definition for at (9 of 9) - abbreviation
abbreviation - Words related to at
Words related to at - Example sentences from the Web for at
Example sentences from the Web for at - I spoke first with Scott Ellman, a student at Wesleyan University and now the Huffington Post editor-at-large for his campus.
I spoke first with Scott Ellman, a student at Wesleyan University and now the Huffington Post editor-at-large for his campus.
The at-home genetics testing company 23andme, established in 2006, helps people learn more about their DNA relatives.
This at-home blood test kit gives a full reading of antioxidant, fatty acid, or vitamin panels.
At-home caretakers are eligible for Medicaid waivers, which allow benefits regardless of income.
Because women with disabilities are one of the most at-risk demographics in the world.
Tressan was monstrous ill-at-ease, and his face lost a good deal of its habitual plethora of colour.
A fellow rudely clada hybrid between man-at-arms and lackeylounged on a musket to confront them in the gateway.
And the Seneschal, moved by that confident promise of evil, threw himself before the men-at-arms.
On the first day, a thousand English archers, supported by men-at-arms, attempted to draw the Scots.
Belhaven made his escape to his own country, and was there beyond the reach of the Serjeant-at-Arms.
British Dictionary definitions for at (1 of 6)
at1 - / (t) /
/ (t) / - preposition
preposition - used to indicate location or positionare they at the table?; staying at a small hotel
used to indicate location or positionare they at the table?; staying at a small hotel
towards; in the direction oflooking at television; throwing stones at windows
used to indicate position in timecome at three o'clock
engaged in; in a state of (being)children at play; stand at ease; he is at his most charming today
(in expressions concerned with habitual activity) during the passing of (esp in the phrase at night)he used to work at night
for; in exchange forit's selling at four pounds
used to indicate the object of an emotionangry at the driver; shocked at his behaviour
where it's at slang the real place of action
SEE MORESEE LESS - Word Origin for at
Word Origin for at - Old English t; related to Old Norse at to, Latin ad to
Old English t; related to Old Norse at to, Latin ad to
Examples of Attached structure in a sentence - Attached structure means any structure which is connected to any other structure by means of a structural connection, such as a roof, stairway, atrium, breezeway or other structural connection.
Attached structure means any structure which is connected to any other structure by means of a structural connection, such as a roof, stairway, atrium, breezeway or other structural connection.
A Single Family Attached structure shall not be required to have a side yard, and a common or party wall may be constructed upon the dividing lines between Lots so that the wall may be partially upon one Lot and partially upon the other, or said common wall may be entirely upon one of the two lots involved.
The notes upon the recorded subdivision plat shall also control as to minimum square footage of each Single Family Detached structure, Single Family Attached structure as well as each Living Unit in a Multi-family structure.
A Single Family Attached structure shall not be required to have a side yard and a common or party wall may be constructed upon the dividing lines between Lots so that the wallmay be partially upon one Lot and partially upon the other or said common wall may be entirely upon one of the two lots involved.
Attached structure shall be subordinate to the main structure characterized at minimum by a lower ridge line.
Barcode - A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths and spacings of parallel lines. These barcodes, now commonly referred to as linear or one-dimensional (1D), can be scanned by special optical scanners, called barcode readers, of which there are several types. Later, two-dimensional (2D) variants were developed, using rectangles, dots, hexagons and other patterns, called matrix codes or 2D barcodes, although they do not use bars as such. 2D barcodes can be read using purpose-built 2D optical scanners, which exist in a few different forms. 2D barcodes can also be read by a digital camera connected to a microcomputer running software that takes a photographic image of the barcode and analyzes the image to deconstruct and decode the 2D barcode. A mobile device with an inbuilt camera, such as smartphone, can function as the latter type of 2D barcode reader using specialized application software. (The same sort of mobile device could also read 1D barcodes, depending on the application software.)
A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths and spacings of parallel lines. These barcodes, now commonly referred to as linear or one-dimensional (1D), can be scanned by special optical scanners, called barcode readers, of which there are several types. Later, two-dimensional (2D) variants were developed, using rectangles, dots, hexagons and other patterns, called matrix codes or 2D barcodes, although they do not use bars as such. 2D barcodes can be read using purpose-built 2D optical scanners, which exist in a few different forms. 2D barcodes can also be read by a digital camera connected to a microcomputer running software that takes a photographic image of the barcode and analyzes the image to deconstruct and decode the 2D barcode. A mobile device with an inbuilt camera, such as smartphone, can function as the latter type of 2D barcode reader using specialized application software. (The same sort of mobile device could also read 1D barcodes, depending on the application software.)
The barcode was invented by Norman Joseph Woodland and Bernard Silver and patented in the US in 1951.[1] The invention was based on Morse code[2] that was extended to thin and thick bars. However, it took over twenty years before this invention became commercially successful. An early use of one type of barcode in an industrial context was sponsored by the Association of American Railroads in the late 1960s. Developed by General Telephone and Electronics (GTE) and called KarTrak ACI (Automatic Car Identification), this scheme involved placing colored stripes in various combinations on steel plates which were affixed to the sides of railroad rolling stock. Two plates were used per car, one on each side, with the arrangement of the colored stripes encoding information such as ownership, type of equipment, and identification number.[3] The plates were read by a trackside scanner, located for instance, at the entrance to a classification yard, while the car was moving past.[4] The project was abandoned after about ten years because the system proved unreliable after long-term use.[3]
Barcodes became commercially successful when they were used to automate supermarket checkout systems, a task for which they have become almost universal. The Uniform Grocery Product Code Council had chosen, in 1973, the barcode design developed by George Laurer. Laurer's barcode, with vertical bars, printed better than the circular barcode developed by Woodland and Silver.[5] Their use has spread to many other tasks that are generically referred to as automatic identification and data capture (AIDC). The first scanning of the now-ubiquitous Universal Product Code (UPC) barcode was on a pack of Wrigley Company chewing gum in June 1974 at a Marsh supermarket in Troy, Ohio, using scanner produced by Photographic Sciences Corporation.[6][5] QR codes, a specific type of 2D barcode, have recently become very popular due to the growth in smartphone ownership.[7]
Other systems have made inroads in the AIDC market, but the simplicity, universality and low cost of barcodes has limited the role of these other systems, particularly before technologies such as radio-frequency identification (RFID) became available after 1995.
In 1948 Bernard Silver, a graduate student at Drexel Institute of Technology in Philadelphia, Pennsylvania, US overheard the president of the local food chain, Food Fair, asking one of the deans to research a system to automatically read product information during checkout.[8] Silver told his friend Norman Joseph Woodland about the request, and they started working on a variety of systems. Their first working system used ultraviolet ink, but the ink faded too easily and was expensive.[9]
Convinced that the system was workable with further development, Woodland left Drexel, moved into his father's apartment in Florida, and continued working on the system. His next inspiration came from Morse code, and he formed his first barcode from sand on the beach. "I just extended the dots and dashes downwards and made narrow lines and wide lines out of them."[9] To read them, he adapted technology from optical soundtracks in movies, using a 500-watt incandescent light bulb shining through the paper onto an RCA935 photomultiplier tube (from a movie projector) on the far side. He later decided that the system would work better if it were printed as a circle instead of a line, allowing it to be scanned in any direction.
On 20 October 1949, Woodland and Silver filed a patent application for "Classifying Apparatus and Method", in which they described both the linear and bull's eye printing patterns, as well as the mechanical and electronic systems needed to read the code. The patent was issued on 7 October 1952 as US Patent 2,612,994.[1] In 1951, Woodland moved to IBM and continually tried to interest IBM in developing the system. The company eventually commissioned a report on the idea, which concluded that it was both feasible and interesting, but that processing the resulting information would require equipment that was some time off in the future.
IBM offered to buy the patent, but the offer was not accepted. Philco purchased the patent in 1962 and then sold it to RCA sometime later.[9]
During his time as an undergraduate, David Jarrett Collins worked at the Pennsylvania Railroad and became aware of the need to automatically identify railroad cars. Immediately after receiving his master's degree from MIT in 1959, he started work at GTE Sylvania and began addressing the problem. He developed a system called KarTrak using blue and red reflective stripes attached to the side of the cars, encoding a six-digit company identifier and a four-digit car number.[9] Light reflected off the colored stripes was read by photomultiplier vacuum tubes.[10]
The Boston and Maine Railroad tested the KarTrak system on their gravel cars in 1961. The tests continued until 1967, when the Association of American Railroads (AAR) selected it as a standard, Automatic Car Identification, across the entire North American fleet. The installations began on 10 October 1967. However, the economic downturn and rash of bankruptcies in the industry in the early 1970s greatly slowed the rollout, and it was not until 1974 that 95% of the fleet was labeled. To add to its woes, the system was found to be easily fooled by dirt in certain applications, which greatly affected accuracy. The AAR abandoned the system in the late 1970s, and it was not until the mid-1980s that they introduced a similar system, this time based on radio tags.[11]
The railway project had failed, but a toll bridge in New Jersey requested a similar system so that it could quickly scan for cars that had purchased a monthly pass. Then the U.S. Post Office requested a system to track trucks entering and leaving their facilities. These applications required special retroreflector labels. Finally, Kal Kan asked the Sylvania team for a simpler (and cheaper) version which they could put on cases of pet food for inventory control.
In 1967, with the railway system maturing, Collins went to management looking for funding for a project to develop a black-and-white version of the code for other industries. They declined, saying that the railway project was large enough, and they saw no need to branch out so quickly.
Collins then quit Sylvania and formed the Computer Identics Corporation.[9] As its first innovations, Computer Identics moved from using incandescent light bulbs in its systems, replacing them with heliumneon lasers, and incorporated a mirror as well, making it capable of locating a barcode up to several feet in front of the scanner. This made the entire process much simpler and more reliable, and typically enabled these devices to deal with damaged labels, as well, by recognizing and reading the intact portions.
Computer Identics Corporation installed one of its first two scanning systems in the spring of 1969 at a General Motors (Buick) factory in Flint, Michigan.[9] The system was used to identify a dozen types of transmissions moving on an overhead conveyor from production to shipping. The other scanning system was installed at General Trading Company's distribution center in Carlstadt, New Jersey to direct shipments to the proper loading bay.
In 1966, the National Association of Food Chains (NAFC) held a meeting on the idea of automated checkout systems. RCA, who had purchased the rights to the original Woodland patent, attended the meeting and initiated an internal project to develop a system based on the bullseye code. The Kroger grocery chain volunteered to test it.
In the mid-1970s, the NAFC established the Ad-Hoc Committee for U.S. Supermarkets on a Uniform Grocery-Product Code to set guidelines for barcode development. In addition, it created a symbol-selection subcommittee to help standardize the approach. In cooperation with consulting firm, McKinsey & Co., they developed a standardized 11-digit code for identifying products. The committee then sent out a contract tender to develop a barcode system to print and read the code. The request went to Singer, National Cash Register (NCR), Litton Industries, RCA, Pitney-Bowes, IBM and many others.[12] A wide variety of barcode approaches was studied, including linear codes, RCA's bullseye concentric circle code, starburst patterns and others.
In the spring of 1971, RCA demonstrated their bullseye code at another industry meeting. IBM executives at the meeting noticed the crowds at the RCA booth and immediately developed their own system. IBM marketing specialist Alec Jablonover remembered that the company still employed Woodland, and he[who?] established a new facility in Raleigh-Durham Research Triangle Park to lead development.
In July 1972, RCA began an 18-month test in a Kroger store in Cincinnati. Barcodes were printed on small pieces of adhesive paper, and attached by hand by store employees when they were adding price tags. The code proved to have a serious problem; the printers would sometimes smear ink, rendering the code unreadable in most orientations. However, a linear code, like the one being developed by Woodland at IBM, was printed in the direction of the stripes, so extra ink would simply make the code "taller" while remaining readable. So on 3 April 1973, the IBM UPC was selected as the NAFC standard. IBM had designed five versions of UPC symbology for future industry requirements: UPC A, B, C, D, and E.[13]
NCR installed a testbed system at Marsh's Supermarket in Troy, Ohio, near the factory that was producing the equipment. On 26 June 1974, Clyde Dawson pulled a 10-pack of Wrigley's Juicy Fruit gum out of his basket and it was scanned by Sharon Buchanan at 8:01 am. The pack of gum and the receipt are now on display in the Smithsonian Institution. It was the first commercial appearance of the UPC.[14]
In 1971, an IBM team was assembled for an intensive planning session, threshing out, 12 to 18 hours a day, how the technology would be deployed and operate cohesively across the system, and scheduling a roll-out plan. By 1973, the team were meeting with grocery manufacturers to introduce the symbol that would need to be printed on the packaging or labels of all of their products. There were no cost savings for a grocery to use it, unless at least 70% of the grocery's products had the barcode printed on the product by the manufacturer. IBM projected that 75% would be needed in 1975. Yet, although this was achieved, there were still scanning machines in fewer than 200 grocery stores by 1977.[15]
Economic studies conducted for the grocery industry committee projected over $40 million in savings to the industry from scanning by the mid-1970s. Those numbers were not achieved in that time-frame and some predicted the demise of barcode scanning. The usefulness of the barcode required the adoption of expensive scanners by a critical mass of retailers while manufacturers simultaneously adopted barcode labels. Neither wanted to move first and results were not promising for the first couple of years, with Business Week proclaiming "The Supermarket Scanner That Failed" in a 1976 article.[14][16]
On the other hand, experience with barcode scanning in those stores revealed additional benefits. The detailed sales information acquired by the new systems allowed greater responsiveness to customer habits, needs and preferences. This was reflected in the fact that about 5 weeks after installing barcode scanners, sales in grocery stores typically started climbing and eventually leveled off at a 1012% increase in sales that never dropped off. There was also a 12% decrease in operating cost for those stores, and this enabled them to lower prices and thereby to increase market share. It was shown in the field that the return on investment for a barcode scanner was 41.5%. By 1980, 8,000 stores per year were converting.[15]
Sims Supermarkets were the first location in Australia to use barcodes, starting in 1979.[17]
In 1981, the United States Department of Defense adopted the use of Code 39 for marking all products sold to the United States military. This system, Logistics Applications of Automated Marking and Reading Symbols (LOGMARS), is still used by DoD and is widely viewed as the catalyst for widespread adoption of barcoding in industrial uses.[18]
Barcodes are widely used around the world in many contexts. In stores, UPC barcodes are pre-printed on most items other than fresh produce from a grocery store. This speeds up processing at check-outs and helps track items and also reduces instances of shoplifting involving price tag swapping, although shoplifters can now print their own barcodes.[19] Barcodes that encode a book's ISBN are also widely pre-printed on books, journals and other printed materials. In addition, retail chain membership cards use barcodes to identify customers, allowing for customized marketing and greater understanding of individual consumer shopping patterns. At the point of sale, shoppers can get product discounts or special marketing offers through the address or e-mail address provided at registration.
Barcodes are widely used in the healthcare and hospital settings, ranging from patient identification (to access patient data, including medical history, drug allergies, etc.) to creating SOAP Notes[20] with barcodes to medication management. They are also used to facilitate the separation and indexing of documents that have been imaged in batch scanning applications, track the organization of species in biology,[21] and integrate with in-motion checkweighers to identify the item being weighed in a conveyor line for data collection.
They can also be used to keep track of objects and people; they are used to keep track of rental cars, airline luggage, nuclear waste, registered mail, express mail and parcels. Barcoded tickets (which may be printed by the customer on their home printer, or stored on their mobile device) allow the holder to enter sports arenas, cinemas, theatres, fairgrounds, and transportation, and are used to record the arrival and departure of vehicles from rental facilities etc. This can allow proprietors to identify duplicate or fraudulent tickets more easily. Barcodes are widely used in shop floor control applications software where employees can scan work orders and track the time spent on a job.
Barcodes are also used in some kinds of non-contact 1D and 2D position sensors. A series of barcodes are used in some kinds of absolute 1D linear encoder. The barcodes are packed close enough together that the reader always has one or two barcodes in its field of view. As a kind of fiducial marker, the relative position of the barcode in the field of view of the reader gives incremental precise positioning, in some cases with sub-pixel resolution. The data decoded from the barcode gives the absolute coarse position. An "address carpet", such as Howell's binary pattern and the Anoto dot pattern, is a 2D barcode designed so that a reader, even though only a tiny portion of the complete carpet is in the field of view of the reader, can find its absolute X,Y position and rotation in the carpet.[22][23]
2D barcodes can embed a hyperlink to a web page. A mobile device with an inbuilt camera might be used to read the pattern and browse the linked website, which can help a shopper find the best price for an item in the vicinity. Since 2005, airlines use an IATA-standard 2D barcode on boarding passes (Bar Coded Boarding Pass (BCBP)), and since 2008 2D barcodes sent to mobile phones enable electronic boarding passes.[24]
Some applications for barcodes have fallen out of use. In the 1970s and 1980s, software source code was occasionally encoded in a barcode and printed on paper (Cauzin Softstrip and Paperbyte[25] are barcode symbologies specifically designed for this application), and the 1991 Barcode Battler computer game system used any standard barcode to generate combat statistics.
Artists have used barcodes in art, such as Scott Blake's Barcode Jesus, as part of the post-modernism movement.
The mapping between messages and barcodes is called a symbology. The specification of a symbology includes the encoding of the message into bars and spaces, any required start and stop markers, the size of the quiet zone required to be before and after the barcode, and the computation of a checksum.
Linear symbologies can be classified mainly by two properties:
Continuous vs. discrete - Characters in discrete symbologies are composed of n bars and n 1 spaces. There is an additional space between characters, but it does not convey information, and may have any width as long as it is not confused with the end of the code.
Characters in discrete symbologies are composed of n bars and n 1 spaces. There is an additional space between characters, but it does not convey information, and may have any width as long as it is not confused with the end of the code.
Characters in continuous symbologies are composed of n bars and n spaces, and usually abut, with one character ending with a space and the next beginning with a bar, or vice versa. A special end pattern that has bars on both ends is required to end the code.
Two-width vs. many-width - A two-width, also called a binary bar code, contains bars and spaces of two widths, "wide" and "narrow". The precise width of the wide bars and spaces is not critical; typically it is permitted to be anywhere between 2 and 3 times the width of the narrow equivalents.
A two-width, also called a binary bar code, contains bars and spaces of two widths, "wide" and "narrow". The precise width of the wide bars and spaces is not critical; typically it is permitted to be anywhere between 2 and 3 times the width of the narrow equivalents.
Some other symbologies use bars of two different heights (POSTNET), or the presence or absence of bars (CPC Binary Barcode). These are normally also considered binary bar codes.
Bars and spaces in many-width symbologies are all multiples of a basic width called the module; most such codes use four widths of 1, 2, 3 and 4 modules.
Some symbologies use interleaving. The first character is encoded using black bars of varying width. The second character is then encoded by varying the width of the white spaces between these bars. Thus characters are encoded in pairs over the same section of the barcode. Interleaved 2 of 5 is an example of this.
Stacked symbologies repeat a given linear symbology vertically.
The most common among the many 2D symbologies are matrix codes, which feature square or dot-shaped modules arranged on a grid pattern. 2D symbologies also come in circular and other patterns and may employ steganography, hiding modules within an image (for example, DataGlyphs).
Linear symbologies are optimized for laser scanners, which sweep a light beam across the barcode in a straight line, reading a slice of the barcode light-dark patterns. Scanning at an angle makes the modules appear wider, but does not change the width ratios. Stacked symbologies are also optimized for laser scanning, with the laser making multiple passes across the barcode.
In the 1990s development of charge-coupled device (CCD) imagers to read barcodes was pioneered by Welch Allyn. Imaging does not require moving parts, as a laser scanner does. In 2007, linear imaging had begun to supplant laser scanning as the preferred scan engine for its performance and durability.
2D symbologies cannot be read by a laser, as there is typically no sweep pattern that can encompass the entire symbol. They must be scanned by an image-based scanner employing a CCD or other digital camera sensor technology.
GTIN barcodes on Coke bottles. The images at right show how the laser of barcode readers "see" the images behind a red filter.
The earliest, and still the cheapest, barcode scanners are built from a fixed light and a single photosensor that is manually moved across the barcode. Barcode scanners can be classified into three categories based on their connection to the computer. The older type is the RS-232 barcode scanner. This type requires special programming for transferring the input data to the application program. Keyboard interface scanners connect to a computer using a PS/2 or AT keyboardcompatible adaptor cable (a "keyboard wedge"). The barcode's data is sent to the computer as if it had been typed on the keyboard.
Like the keyboard interface scanner, USB scanners do not need custom code for transferring input data to the application program. On PCs running Windows the human interface device emulates the data merging action of a hardware "keyboard wedge", and the scanner automatically behaves like an additional keyboard.
Most modern smartphones are able to decode barcode using their built-in camera. Google's mobile Android operating system can use their own Google Lens application to scan QR codes, or third party apps like Barcode Scanner to read both one-dimensional barcodes and QR codes. Nokia's Symbian operating system featured a barcode scanner,[26] while mbarcode[27] is a QR code reader for the Maemo operating system. In Apple iOS 11, the native camera app can decode QR codes and can link to URLs, join wireless networks, or perform other operations depending on the QR Code contents.[28] Other paid and free apps are available with scanning capabilities for other symbologies or for earlier iOS versions.[29] With BlackBerry devices, the App World application can natively scan barcodes and load any recognized Web URLs on the device's Web browser. Windows Phone 7.5 is able to scan barcodes through the Bing search app. However, these devices are not designed specifically for the capturing of barcodes. As a result, they do not decode nearly as quickly or accurately as a dedicated barcode scanner or portable data terminal.[citation needed]
It is common for producers and users of bar codes to have a quality management system which includes verification and validation of bar codes.[30] Barcode verification examines scanability and the quality of the barcode in comparison to industry standards and specifications.[31] Barcode verifiers are primarily used by businesses that print and use barcodes. Any trading partner in the supply chain can test barcode quality. It is important to verify a barcode to ensure that any reader in the supply chain can successfully interpret a barcode with a low error rate. Retailers levy large penalties for non-compliant barcodes. These chargebacks can reduce a manufacturer's revenue by 2% to 10%.[32]
A barcode verifier works the way a reader does, but instead of simply decoding a barcode, a verifier performs a series of tests. For linear barcodes these tests are:
The difference between the space reflectance (Rs) and adjoining bar reflectance (Rb). EC=Rs-Rb
Symbol Contrast is the difference in reflectance values of the lightest space (including the quiet zone) and the darkest bar of the symbol. The greater the difference, the higher the grade. The parameter is graded as either A, B, C, D, or F. SC=Rmax-Rmin
The difference between the space reflectance (Rs) and adjoining bar reflectance (Rb). EC=Rs-Rb
The parameter is graded either A, B, C, D, or F. This grade is based on the relationship between minimum edge contrast (ECmin) and symbol contrast (SC). MOD=ECmin/SC The greater the difference between minimum edge contrast and symbol contrast, the lower the grade. Scanners and verifiers perceive the narrower bars and spaces to have less intensity than wider bars and spaces; the comparison of the lesser intensity of narrow elements to the wide elements is called modulation. This condition is affected by aperture size.
In discrete barcodes, the space that disconnects the two contiguous characters. When present, inter-character gaps are considered spaces (elements) for purposes of edge determination and reflectance parameter grades.
Can be graded as A, B, C, D, or F. The Decodability grade indicates the amount of error in the width of the most deviant element in the symbol. The less deviation in the symbology, the higher the grade. Decodability is a measure of print accuracy using the symbology reference decode algorithm.
Depending on the parameter, each ANSI test is graded from 0.0 to 4.0 (F to A), or given a pass or fail mark. Each grade is determined by analyzing the scan reflectance profile (SRP), an analog graph of a single scan line across the entire symbol. The lowest of the 8 grades is the scan grade, and the overall ISO symbol grade is the average of the individual scan grades. For most applications a 2.5 (C) is the minimal acceptable symbol grade.[35]
Compared with a reader, a verifier measures a barcode's optical characteristics to international and industry standards. The measurement must be repeatable and consistent. Doing so requires constant conditions such as distance, illumination angle, sensor angle and verifier aperture. Based on the verification results, the production process can be adjusted to print higher quality barcodes that will scan down the supply chain.
Bar code validation may include evaluations after use (and abuse) testing such as sunlight, abrasion, impact, moisture, etc.[36]
Barcode verifier standards are defined by the International Organization for Standardization (ISO), in ISO/IEC 15426-1 (linear) or ISO/IEC 15426-2 (2D).[citation needed] The current international barcode quality specification is ISO/IEC 15416 (linear) and ISO/IEC 15415 (2D).[citation needed] The European Standard EN 1635 has been withdrawn and replaced by ISO/IEC 15416. The original U.S. barcode quality specification was ANSI X3.182. (UPCs used in the US ANSI/UCC5).[citation needed] As of 2011 the ISO workgroup JTC1 SC31 was developing a Direct Part Marking (DPM) quality standard: ISO/IEC TR 29158.[37]
In point-of-sale management, barcode systems can provide detailed up-to-date information on the business, accelerating decisions and with more confidence. For example:
Fast-selling items can be identified quickly and automatically reordered.
Slow-selling items can be identified, preventing inventory build-up.
The effects of merchandising changes can be monitored, allowing fast-moving, more profitable items to occupy the best space.
Historical data can be used to predict seasonal fluctuations very accurately.
Items may be repriced on the shelf to reflect both sale prices and price increases.
This technology also enables the profiling of individual consumers, typically through a voluntary registration of discount cards. While pitched as a benefit to the consumer, this practice is considered to be potentially dangerous by privacy advocates.[which?]
Besides sales and inventory tracking, barcodes are very useful in logistics and supply chain management.
When a manufacturer packs a box for shipment, a Unique Identifying Number (UID) can be assigned to the box.
A database can link the UID to relevant information about the box; such as order number, items packed, quantity packed, destination, etc.
The information can be transmitted through a communication system such as Electronic Data Interchange (EDI) so the retailer has the information about a shipment before it arrives.
Shipments that are sent to a Distribution Center (DC) are tracked before forwarding. When the shipment reaches its final destination, the UID gets scanned, so the store knows the shipment's source, contents, and cost.
Barcode scanners are relatively low cost and extremely accurate compared to key-entry, with only about 1 substitution error in 15,000 to 36 trillion characters entered.[38][unreliable source?] The exact error rate depends on the type of barcode.
A first generation, "one dimensional" barcode that is made up of lines and spaces of various widths that create specific patterns.
An Australia Post barcode as used on a business reply paid envelope and applied by automated sorting machines to other mail when initially processed in fluorescent ink .
Old format used in libraries and blood banks and on airbills (out of date, but still widely used in libraries)
Addon code (magazines), GS1-approved not an own symbology to be used only with an EAN/UPC according to ISO/IEC 15420
Addon code (books), GS1-approved not an own symbology to be used only with an EAN/UPC according to ISO/IEC 15420
Various, GS1-approved just an application of the Code 128 (ISO/IEC 15417) using the ANS MH10.8.2 AI Datastructures. It is not a separate symbology.
GS1 DataBar, formerly Reduced Space Symbology (RSS)
United States Postal Service, replaces both POSTNET and PLANET symbols (formerly named OneCode)
Non-retail packaging levels, GS1-approved is just an Interleaved 2/5 Code (ISO/IEC 16390) with a few additional specifications, according to the GS1 General Specifications
Interleaved 2 of 5 barcode to encode an addon to ITF-14 and ITF-16 barcodes. The code is used to encode additional data such as items quantity or container weight
A matrix code, also termed a 2D barcode or simply a 2D code, is a two-dimensional way to represent information. It is similar to a linear (1-dimensional) barcode, but can represent more data per unit area.
A type of marker used for placing content inside augmented reality applications. Some AR Codes can contain QR codes inside, so that content AR content can be linked to.[39] See also ARTag.
Designed by Andrew Longacre at Welch Allyn (now Honeywell Scanning and Mobility). Public domain. International Standard: ISO/IEC 24778
bCode - A barcode designed for the study of insect behavior.[40] Encodes an 11 bit identifier and 16 bits of read error detection and error correction information. Predominately used for marking honey bees, but can also be applied to other animals.
A barcode designed for the study of insect behavior.[40] Encodes an 11 bit identifier and 16 bits of read error detection and error correction information. Predominately used for marking honey bees, but can also be applied to other animals.
A 25 bit (5x5) code matrix of black and white pixels that is unique to each tag surrounded by a white pixel border and a black pixel border. The 25-bit matrix consists of a 15-bit identity code, and a 10-bit error check.[41] It is designed to be a low-cost, image-based tracking system for the study of animal behavior and locomotion.
A 2D barcode with honeycomb structures suitable for mobile tagging and was developed by the Swiss company connvision AG.
A type of data tag which holds much more information than a barcode over the same area. They were developed by a team led by Ramesh Raskar at the MIT Media Lab. The bokode pattern is a tiled series of Data Matrix codes.
A high-capacity 2D barcode is used on piqlFilm by Piql AS[42]
Code 1 - Public domain. Code 1 is currently used in the health care industry for medicine labels and the recycling industry to encode container content for sorting.[43]
Public domain. Code 1 is currently used in the health care industry for medicine labels and the recycling industry to encode container content for sorting.[43]
The Code 16K (1988) is a multi-row bar code developed by Ted Williams at Laserlight Systems (USA) in 1992. In the US and France, the code is used in the electronics industry to identify chips and printed circuit boards. Medical applications in the USA are well known. Williams also developed Code 128, and the structure of 16K is based on Code 128. Not coincidentally, 128 squared happened to equal 16,000 or 16K for short. Code 16K resolved an inherent problem with Code 49. Code 49's structure requires a large amount of memory for encoding and decoding tables and algorithms. 16K is a stacked symbology.[44][45]
ColorCode - ColorZip[46] developed colour barcodes that can be read by camera phones from TV screens; mainly used in Korea.[47]
ColorZip[46] developed colour barcodes that can be read by camera phones from TV screens; mainly used in Korea.[47]
Color Construct Code - Color Construct Code is one of the few barcode symbologies designed to take advantage of multiple colors.[48][49]
Color Construct Code is one of the few barcode symbologies designed to take advantage of multiple colors.[48][49]
From Palo Alto Research Center (also termed Xerox PARC).[54]
Patented.[55] DataGlyphs can be embedded into a half-tone image or background shading pattern in a way that is almost perceptually invisible, similar to steganography.[56][57]
From Microscan Systems, formerly RVSI Acuity CiMatrix/Siemens. Public domain. Increasingly used throughout the United States. Single segment Data Matrix is also termed Semacode. International Standard: ISO/IEC 16022.
The Digimarc Barcode is a unique identifier, or code, based on imperceptible patterns that can be applied to marketing materials, including packaging, displays, ads in magazines, circulars, radio and television[58]
patterned paper used in conjunction with a digital pen to create handwritten digital documents. The printed dot pattern uniquely identifies the position coordinates on the paper.
Standardized as AIM Dotcode Rev 3.0. Public domain. Used to track individual cigarette and pharmaceutical packages.
Introduced by GS1 US and GS1 Germany, the DWCode is a unique, imperceptible data carrier that is repeated across the entire graphics design of a package[61]
EZcode - Designed for decoding by cameraphones;[62] from ScanLife.[63]
Designed for decoding by cameraphones;[62] from ScanLife.[63]
From Iconlab, Inc. The standard 2D barcode in South Korea. All 3 South Korean mobile carriers put the scanner program of this code into their handsets to access mobile internet, as a default embedded program.
Designed by NextCode Corporation, specifically to work with mobile phones and mobile services.[65] It is implementing an independent error detection technique preventing false decoding, it uses a variable-size error correction polynomial, which depends on the exact size of the code.[66]
Designed to disseminate high capacity mobile phone content via existing colour print and electronic media, without the need for network connectivity
American proprietary and patented 2D barcode from NeoMedia Technologies, Inc.[63]
Initially developed, patented and owned by Denso Wave for automotive components management; they have chosen not to exercise their patent rights. Can encode Latin and Japanese Kanji and Kana characters, music, images, URLs, emails. De facto standard for Japanese cell phones. Used with BlackBerry Messenger to pick up contacts rather than using a PIN code. The most frequently used type of code to scan with smartphones. Public Domain. International Standard: ISO/IEC 18004
Screencode - Developed and patented[67][68] by Hewlett-Packard Labs. A time-varying 2D pattern using to encode data via brightness fluctuations in an image, for the purpose of high bandwidth data transfer from computer displays to smartphones via smartphone camera input. Inventors Timothy Kindberg and John Collomosse, publicly disclosed at ACM HotMobile 2008.[69]
Developed and patented[67][68] by Hewlett-Packard Labs. A time-varying 2D pattern using to encode data via brightness fluctuations in an image, for the purpose of high bandwidth data transfer from computer displays to smartphones via smartphone camera input. Inventors Timothy Kindberg and John Collomosse, publicly disclosed at ACM HotMobile 2008.[69]
Circular barcodes for camera phones. Originally from High Energy Magic Ltd in name Spotcode. Before that most likely termed TRIPCode.
A proprietary code developed by Electronic Automation Ltd. in 1981. It is possible to encode more than 100 numeric digits in a space of only 5mm x 5mm. User selectable error correction allows up to 40% of the code to be destroyed and still remain readable. The code is used in the pharmaceutical industry and has an advantage that it can be applied to products and materials in a wide variety of ways, including printed labels, ink-jet printing, laser-etching, indenting or hole punching.[44][73][74]
Designed for mobile phone scanning.[75] Developed by Lark Computer, a Romanian company.[66]
Developed and patented by VOICEYE, Inc. in South Korea, it aims to allow blind and visually impaired people to access printed information. It also claims to be the 2D barcode that has the world's largest storage capacity.
GTIN-12 number encoded in UPC-A barcode symbol. First and last digit are always placed outside the symbol to indicate Quiet Zones that are necessary for barcode scanners to work properly
EAN-13 (GTIN-13) number encoded in EAN-13 barcode symbol. First digit is always placed outside the symbol, additionally right quiet zone indicator (>) is used to indicate Quiet Zones that are necessary for barcode scanners to work properly
"Wikipedia, The Free Encyclopedia" in several languages encoded in DataGlyphs
Two different 2D barcodes used in film: Dolby Digital between the sprocket holes with the "Double-D" logo in the middle, and Sony Dynamic Digital Sound in the blue area to the left of the sprocket holes
The QR Code for the Wikipedia URL. "Quick Response", the most popular 2D barcode. It is open in that the specification is disclosed and the patent is not exercised.[76]
MaxiCode example. This encodes the string "Wikipedia, The Free Encyclopedia"
detail of Twibright Optar scan from laser printed paper, carrying 32 kbit/s Ogg Vorbis digital music (48 seconds per A4 page)
In media, in 2011, the National Film Board of Canada and ARTE France launched a web documentary entitled Barcode.tv, which allows users to view films about everyday objects by scanning the product's barcode with their iPhone camera.[79][80]
In the TV series Dark Angel, the protagonist and the other transgenics in the Manticore X-series have barcodes on the back of their necks.
In video games, the protagonist of the Hitman video game series has a barcode tattoo on the back of his head. Also, QR codes can be scanned for an extra mission on Watch Dogs.
In the Terminator films, Skynet burns barcodes onto the inside surface of the wrists of captive humans (in a similar location to the WW2 concentration camp tattoos) as a unique identifier.
In music, Dave Davies of The Kinks released a solo album in 1980, AFL1-3603, which featured a giant barcode on the front cover in place of the musician's head. The album's name was also the barcode number.
The April 1978 issue of Mad Magazine featured a giant barcode on the cover, with the blurb "[Mad] Hopes this issue jams up every computer in the country...for forcing us to deface our covers with this yecchy UPC symbol from now on!"
The 2018 videogame Judgment features QR Codes that protagonist Takayuki Yagami can photograph with his phone camera. These are mostly to unlock parts for Yagami's Drone.[83]
Interactive Textbooks were first published by Harcourt College Publishers to Expand Education Technology with Interactive Textbooks.[84]
Some brands integrate custom designs into barcodes (while keeping them readable) on their consumer products.
There was minor skepticism from conspiracy theorists, who considered barcodes to be an intrusive surveillance technology, and from some Christians, pioneered by a 1982 book The New Money System 666 by Mary Stewart Relfe, who thought the codes hid the number 666, representing the "Number of the Beast".[85] Old Believers, a separation of the Russian Orthodox Church, believe barcodes are the stamp of the Antichrist.[86] Television host Phil Donahue described barcodes as a "corporate plot against consumers".[87]
^ "How Barcodes Work". Stuff You Should Know. 4 June 2019. Retrieved 5 June 2019.
^ Keyes, John (22 August 2003). "KarTrak". John Keyes Boston photoblogger. Images from Boston, New England, and beyond. John Keyes. Archived from the original on 10 March 2014. Retrieved 26 May 2013.
^ Graham-White, Sean (August 1999). "Do You Know Where Your Boxcar Is?". Trains. 59 (8): 4853.
^ Nelson, Benjamin (1997). Punched Cards To Bar Codes: A 200-year journey. Peterborough, N.H.: Helmers. ISBN 9780911261127.
^ a b Selmeier, Bill (2009). Spreading the Barcode. Lulu. pp. 26, 214, 236, 238, 244, 245, 236, 238, 244, 245. ISBN 978-0-578-02417-2.
^ Rawsthorn, Alice (23 February 2010). "Scan Artists". New York Times. Retrieved 31 July 2015.
^ "Barcode". iWatch Systems. 2 May 2011. Retrieved 28 November 2011.
^ Oberfield, Craig. "QNotes Barcode System". US Patented #5296688. Quick Notes Inc. Retrieved 15 December 2012.
^ Harmon, Craig K.; Adams, Russ (1989). Reading Between The Lines:An Introduction to Bar Code Technology. Peterborough, NH: Helmers. p. 13. ISBN 0-911261-00-1.
^ "About". Colour Code Technologies. Archived from the original on 29 August 2012. Retrieved 4 November 2012.
^ 5825015, Chan, John Paul & GB, "United States Patent: 5825015 Machine readable binary codes", issued 20 October 1998
^ "US Patent 5825015". pdfpiw.uspto.gov. 20 October 1998. Retrieved 12 January 2019.
^ "Trillcode Barcode". Barcoding, Inc. 17 February 2009. Retrieved 12 January 2019.
Automating Management Information Systems: Barcode Engineering and Implementation Harry E. Burke, Thomson Learning, ISBN 0-442-20712-3
Automating Management Information Systems: Principles of Barcode Applications Harry E. Burke, Thomson Learning, ISBN 0-442-20667-4
The Bar Code Book Roger C. Palmer, Helmers Publishing, ISBN 0-911261-09-5, 386 pages
The Bar Code Manual Eugene F. Brighan, Thompson Learning, ISBN 0-03-016173-8
Handbook of Bar Coding Systems Harry E. Burke, Van Nostrand Reinhold Company, ISBN 978-0-442-21430-2, 219 pages
Lines of Communication Craig K. Harmon, Helmers Publishing, ISBN 0-911261-07-9, 425 pages
Punched Cards to Bar Codes Benjamin Nelson, Helmers Publishing, ISBN 0-911261-12-5, 434 pages
Reading Between The Lines Craig K. Harmon and Russ Adams, Helmers Publishing, ISBN 0-911261-00-1, 297 pages
The Black and White Solution: Bar Code and the IBM PC Russ Adams and Joyce Lane, Helmers Publishing, ISBN 0-911261-01-X, 169 pages
Sourcebook of Automatic Identification and Data Collection Russ Adams, Van Nostrand Reinhold, ISBN 0-442-31850-2, 298 pages
Inside Out: The Wonders of Modern Technology Carol J. Amato, Smithmark Pub, ISBN 0831746572, 1993
beginning - Definition of beginning
Definition of beginning - 1 : the point at which something begins : start It was clear from the beginning that she would win.
1 : the point at which something begins : start It was clear from the beginning that she would win.
2 : the first part We missed the beginning of the movie.
3 : origin, source No one remembers what the beginning of the feud was.
4 : a rudimentary stage or early period usually used in plural the company's modest beginnings in an old warehouseShe came from humble beginnings.
Examples of beginning in a Sentence - Noun Go back to the beginning of the song. We were late, so we missed the beginning of the movie. The changes that have been made so far are just the beginning. There are many more changes still to come. He came from humble beginnings. the company's modest beginnings in an old warehouse Adjective the beginning part of the book is a portrait of Europe on the eve of the World War I a course in beginning geology for nonscience majors
Noun Go back to the beginning of the song. We were late, so we missed the beginning of the movie. The changes that have been made so far are just the beginning. There are many more changes still to come. He came from humble beginnings. the company's modest beginnings in an old warehouse Adjective the beginning part of the book is a portrait of Europe on the eve of the World War I a course in beginning geology for nonscience majors
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Building code - Set of rules that specify the standards for constructed objects such as buildings and nonbuilding structures
Set of rules that specify the standards for constructed objects such as buildings and nonbuilding structures
A building code (also building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and nonbuilding structures. Buildings must conform to the code to obtain planning permission, usually from a local council. The main purpose of building codes is to protect public health, safety and general welfare as they relate to the construction and occupancy of buildings and structures. The building code becomes law of a particular jurisdiction when formally enacted by the appropriate governmental or private authority.[1]
Examples of building codes began in ancient times.[2] In the USA the main codes are the International Building Code or International Residential Code [IBC/IRC], electrical codes and plumbing, mechanical codes. Fifty states and the District of Columbia have adopted the I-Codes at the state or jurisdictional level.[3] In Canada, national model codes are published by the National Research Council of Canada.[4] In the United Kingdom, compliance with Building Regulations is monitored by building control bodies, either Approved Inspectors or Local Authority Building Control departments. Building Control regularisation charges apply in the event that work is undertaken which should have had been inspected at the time of the work if this was not done.[5]
The practice of developing, approving, and enforcing building codes varies considerably among nations. In some countries building codes are developed by the government agencies or quasi-governmental standards organizations and then enforced across the country by the central government. Such codes are known as the national building codes (in a sense they enjoy a mandatory nationwide application).
In other countries, where the power of regulating construction and fire safety is vested in local authorities, a system of model building codes is used. Model building codes have no legal status unless adopted or adapted by an authority having jurisdiction. The developers of model codes urge public authorities to reference model codes in their laws, ordinances, regulations, and administrative orders. When referenced in any of these legal instruments, a particular model code becomes law. This practice is known as 'adoption by reference'. When an adopting authority decides to delete, add, or revise any portions of the model code adopted, it is usually required by the model code developer to follow a formal adoption procedure in which those modifications can be documented for legal purposes.
There are instances when some local jurisdictions choose to develop their own building codes. At some point in time all major cities in the United States had their own building codes. However, due to ever increasing complexity and cost of developing building regulations, virtually all municipalities in the country have chosen to adopt model codes instead. For example, in 2008 New York City abandoned its proprietary 1968 New York City Building Code in favor of a customized version of the International Building Code.[8] The City of Chicago remains the only municipality in America that continues to use a building code the city developed on its own as part of the Municipal Code of Chicago.
In Europe, the Eurocode: Basis of structural design, is a pan-European building code that has superseded the older national building codes. Each country now has National Annexes to localize the contents of the Eurocodes.
Similarly, in India, each municipality and urban development authority has its own building code, which is mandatory for all construction within their jurisdiction. All these local building codes are variants of a National Building Code,[9] which serves as model code proving guidelines for regulating building construction activity.
Building codes have a long history. The earliest known written building code is included in the Code of Hammurabi,[2] which dates from circa 1772 BC.
The book of Deuteronomy in the Hebrew Bible stipulated that parapets must be constructed on all houses to prevent people from falling off.[10]
In Paris, under the reconstruction of much of the city under the Second Empire (185270), great blocks of apartments were erected[11] and the height of buildings was limited by law to five or six stories at most.
After the Great Fire of London in 1666, which had been able to spread so rapidly through the densely built timber housing of the city, the Rebuilding of London Act was passed in the same year as the first significant building regulation.[12] Drawn up by Sir Matthew Hale, the Act regulated the rebuilding of the city, required housing to have some fire resistance capacity and authorised the City of London Corporation to reopen and widen roads.[13] The Laws of the Indies were passed in the 1680s by the Spanish Crown to regulate the urban planning for colonies throughout Spain's worldwide imperial possessions.
The first systematic national building standard was established with the London Building Act of 1844. Among the provisions, builders were required to give the district surveyor two days' notice before building, regulations regarding the thickness of walls, height of rooms, the materials used in repairs, the dividing of existing buildings and the placing and design of chimneys, fireplaces and drains were to be enforced and streets had to be built to minimum requirements.[14]
The Metropolitan Buildings Office was formed to regulate the construction and use of buildings throughout London. Surveyors were empowered to enforce building regulations, which sought to improve the standard of houses and business premises, and to regulate activities that might threaten public health. In 1855 the assets, powers and responsibilities of the office passed to the Metropolitan Board of Works.
The City of Baltimore passed its first building code in 1859. The Great Baltimore Fire occurred in February, 1904. Subsequent changes were made that matched other cities.[15] In 1904, a Handbook of the Baltimore City Building Laws was published. It served as the building code for four years. Very soon, a formal building code was drafted and eventually adopted in 1908.
The structural failure of the tank that caused the Great Molasses Flood of 1919 prompted the Boston Building Department to require engineering and architectural calculations be filed and signed. U.S. cities and states soon began requiring sign-off by registered professional engineers for the plans of major buildings.[16]
The purpose of building codes is to provide minimum standards for safety, health, and general welfare including structural integrity, mechanical integrity (including sanitation, water supply, light, and ventilation), means of egress, fire prevention and control, and energy conservation.[17][18] Building codes generally include:
Standards for structure, placement, size, usage, wall assemblies, fenestration size/locations, egress rules, size/location of rooms, foundations, floor assemblies, roof structures/assemblies, energy efficiency, stairs and halls, mechanical, electrical, plumbing, site drainage & storage, appliance, lighting, fixtures standards, occupancy rules, and swimming pool regulations
Fire code rules to minimize the risk of a fire and to ensure safe evacuation in the event of such an emergency[citation needed]
Requirements for specific building uses (for example, storage of flammable substances, or housing a large number of people)
Energy provisions and consumption - Grandfather clauses: Unless the building is being renovated, the building code usually does not apply to existing buildings.
Grandfather clauses: Unless the building is being renovated, the building code usually does not apply to existing buildings.
Minimum and maximum room ceiling heights, exit sizes and location
Qualification of individuals or corporations doing the work - For high structures, anti-collision markers for the benefit of aircraft
For high structures, anti-collision markers for the benefit of aircraft
Building codes are generally separate from zoning ordinances, but exterior restrictions (such as setbacks) may fall into either category.
Designers use building code standards out of substantial reference books during design. Building departments review plans submitted to them before construction, issue permits [or not] and inspectors verify compliance to these standards at the site during construction.
There are often additional codes or sections of the same building code that have more specific requirements that apply to dwellings or places of business and special construction objects such as canopies, signs, pedestrian walkways, parking lots, and radio and television antennas.
The energy codes of the United States are adopted at the state and municipal levels and are based on the International Energy Conservation Code (IECC). Previously, they were based on the Model Energy Code (MEC).
As of March 2017, the following residential codes have been partially or fully adopted by states:[19]
2015 IECC or equivalent (California, Illinois, Maryland, Massachusetts, Michigan, Pennsylvania, New Jersey, New York, Vermont, Washington)
2012 IECC or equivalent (Alabama, Connecticut, Delaware, District of Columbia, Florida, Iowa, Minnesota, Nevada, Rhode Island, Texas)
2009 IECC or equivalent (Arkansas, Georgia, Idaho, Indiana, Kentucky, Louisiana, Montana, Nebraska, New Hampshire, New Mexico, North Carolina, Ohio, Oklahoma, Oregon, South Carolina, Tennessee, Virginia, West Virginia, Wisconsin)
2006 IECC or equivalent (Utah) - <2006 IECC or no statewide code (Alaska, Arizona, Colorado, Kansas, Maine, Mississippi, Missouri, North Dakota, South Dakota, Wyoming)
<2006 IECC or no statewide code (Alaska, Arizona, Colorado, Kansas, Maine, Mississippi, Missouri, North Dakota, South Dakota, Wyoming)
Historical energy codes in the United States[edit]
As of September 2005, the following residential energy codes had been partially or fully adopted by states:[20]
2003-2004 IECC or equivalent (Alaska, Arkansas, California, Connecticut, Idaho, Kansas, Nebraska, Maryland, Montana, New Mexico, Ohio, Pennsylvania, South Carolina, Utah, Virginia, Washington)
1998-2001 IECC or equivalent (Alabama, Delaware, District of Columbia, Florida, Georgia, Kentucky, Michigan, New Hampshire, New York, North Carolina, Oregon, Texas, Vermont, West Virginia, Wisconsin)
<1998 IECC (Hawaii, Indiana, Iowa, Louisiana, Massachusetts, Minnesota, New Jersey, North Dakota, Tennessee)
No statewide code / weaker (Arizona, Colorado, Illinois, Maine, Mississippi, Missouri, Nevada, Oklahoma, South Dakota, Wyoming)
As of January 2004, the following residential energy codes had been partially or fully adopted by states:[20]
2003 IECC or IRC (Kansas, New Mexico, Utah)
2000 IECC or IRC or equivalent (Alabama, California, Idaho, Florida, Georgia, Kentucky, Maryland, New Hampshire, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Texas, Virginia, Washington, West Virginia, Wisconsin)
1998 IECC (Oklahoma) - 1995 MEC or equivalent (Alaska, Connecticut, Hawaii, Massachusetts, Louisiana, Minnesota, New Jersey, Vermont)
1995 MEC or equivalent (Alaska, Connecticut, Hawaii, Massachusetts, Louisiana, Minnesota, New Jersey, Vermont)
1993 MEC or equivalent (Delaware, Montana, North Dakota)
1992 MEC or equivalent (Arkansas, Indiana, Iowa, Tennessee)
No code or code not EPAct compliant (Arizona, Colorado, Illinois, Maine, Michigan, Mississippi, Missouri, Nebraska, Nevada, South Dakota, Wyoming)
As of Fall 2000, the following residential energy codes had been partially or fully adopted by states:[20]
2000 IECC rule making (Maryland, New York, Pennsylvania, South Carolina)
1995 MEC or equivalent (Alaska, California, Connecticut, Florida, Georgia, Hawaii, Louisiana, Massachusetts, Minnesota, New Hampshire, North Carolina, Ohio, Oklahoma, Oregon, Rhode Island, Utah, Vermont, Virginia, Washington, Wisconsin, Wyoming)
1993 MEC or equivalent (Alabama, Delaware, Kansas, Montana, North Dakota)
1992 MEC or equivalent (Arkansas, Indiana, Iowa, Kentucky, New Mexico, Tennessee)
No code or code not EPAct compliant (Arizona, Colorado, Idaho, Illinois, Maine, Michigan, Mississippi, Missouri, Nebraska, Nevada, New Jersey, South Dakota, Texas, West Virginia)
As of 1998, three states (Ohio, Michigan, and Virginia) had adopted the 1993 MEC residential energy code. The remaining states had adopted either: a state-written code; a regional code; a prior version of the MEC or American Society of Heating, Refrigerating and Air Conditioning Engineers standards; or no code at all.[21]
^ 'Charles II, 1666: An Act for rebuilding the City of London.', Statutes of the Realm: volume 5: 162880 (1819), pp. 60312. URL: british-history.ac.uk, date accessed: 08 March 2007.
^ 'Book 1, Ch. 15: From the Fire to the death of Charles II', A New History of London: Including Westminster and Southwark (1773), pp. 23055. URL: http://www.british-history.ac.uk/report.asp?compid=46732. Date accessed: 07 March 2007.
^ Baltimore: The Building of an American City, Sherry H. Olson, Published 1997, Johns Hopkins University Press, Baltimore (Md.), ISBN 0-8018-5640-X, p. 248.
^ Hageman, Jack M., and Brian E. P. Beeston. Contractor's guide to the building code. 6th ed. Carlsbad, CA: Craftsman Book Co., 2008. 10. Print.
^ Wexler, Harry J., and Richard Peck. Housing and local government: a research guide for policy makers and planners. Lexington, Mass. u.a.: Lexington Books, 1974. 53. Print.
^ a b c Historical archives of the Building Codes Assistance Project.
^ Jones, Ted; Norland, Douglas; Prindle, William (1998). "Opportunity Lost: Better Energy Codes for Affordable Housing and a Cleaner Environment". Alliance to Save Energy.
Examples of Building face in a sentence - Building face means the general outer surface of any exterior wall of a building or other structure
Building face means the general outer surface of any exterior wall of a building or other structure
Blade Sign: A type of Sign that projects perpendicularly from a Building Face, not exceeding five feet in width, which has a vertical dimension that exceeds the horizontal dimension and may or may not extend above a roof line.
Building Face: The general outer surface, not including cornices, bay windows, or architectural projections, of any wall of a building.
Sidewalk Signs shall meet the following conditions: Standard SizeMaximum of two (2) sign faces, no greater than 0.55 m2 eachHeight1 mSeparation3 m from any driveway AccessPlaced as close to the Building Face as possible, maintaining an unobstructed sidewalk width of 1.5 m during business hours and taken indoors at all other times.
Wall Signs: One (1) Wall Sign shall be permitted per Building Face, not to exceed two (2) Wall Signs per building.
Front Building Face Area: The facade of the building facing the front line calculated as its width multiplied by the building height.
This wall in Beacon Hill, Boston shows different types of brickwork and stone foundations.
Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand and wood, even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes.[1]
This section needs expansion. You can help by adding to it. (April 2014)
In history there are trends in building materials from being natural to becoming more man-made and composite; biodegradable to imperishable; indigenous (local) to being transported globally; repairable to disposable; chosen for increased levels of fire-safety, and improved seismic resistance.. These trends tend to increase the initial and long term economic, ecological, energy, and social costs of building materials.
Initial economic cost of building materials is the purchase price. This is often what governs decision making about what materials to use. Sometimes people take into consideration the energy savings or durability of the materials and see the value of paying a higher initial cost in return for a lower lifetime cost. For example, an asphalt shingle roof costs less than a metal roof to install, but the metal roof will last longer so the lifetime cost is less per year. Some materials may require more care than others, maintaining costs specific to some materials may also influence the final decision. Risks when considering lifetime cost of a material is if the building is damaged such as by fire or wind, or if the material is not as durable as advertised. The cost of materials should be taken into consideration to bear the risk to buy combustive materials to enlarge the lifetime. It is said that, "if it must be done, it must be done well".
Pollution costs can be macro and micro. The macro, environmental pollution of extraction industries building materials rely on such as mining, petroleum, and logging produce environmental damage at their source and in transportation of the raw materials, manufacturing, transportation of the products, retailing, and installation. An example of the micro aspect of pollution is the off-gassing of the building materials in the building or indoor air pollution. Red List building materials are materials found to be harmful. Also the carbon footprint, the total set of greenhouse gas emissions produced in the life of the material. A life-cycle analysis also includes the reuse, recycling, or disposal of construction waste. Two concepts in building which account for the ecological economics of building materials are green building and sustainable development.
the Initial energy costs include the amount of energy consumed to produce, deliver and install the material. The long term energy cost is the economic, ecological, and social costs of continuing to produce and deliver energy to the building for its use, maintenance, and eventual removal. The initial embodied energy of a structure is the energy consumed to extract, manufacture, deliver, install, the materials. The lifetime embodied energy continues to grow with the use, maintenance, and reuse/recycling/disposal of the building materials themselves and how the materials and design help minimize the life-time energy consumption of the structure.
Social costs are injury and health of the people producing and transporting the materials and potential health problems of the building occupants if there are problems with the building biology. Globalization has had significant impacts on people both in terms of jobs, skills, and self-sufficiency are lost when manufacturing facilities are closed and the cultural aspects of where new facilities are opened. Aspects of fair trade and labor rights are social costs of global building material manufacturing.
Brush structures are built entirely from plant parts and were used in primitive cultures such as Native Americans and [2] pygmy peoples in Africa[3] These are built mostly with branches, twigs and leaves, and bark, similar to a beaver's lodge. These were variously named wikiups, lean-tos, and so forth.
An extension on the brush building idea is the wattle and daub process in which clay soils or dung, usually cow, are used to fill in and cover a woven brush structure. This gives the structure more thermal mass and strength. Wattle and daub is one of the oldest building techniques.[4] Many older timber frame buildings incorporate wattle and daub as non load bearing walls between the timber frames.
Snow and occasionally ice,[5] were used by the Inuit peoples for igloos and snow is used to build a shelter called a quinzhee. Ice has also been used for ice hotels as a tourist attraction in northern climates.[6]
Clay based buildings usually come in two distinct types. One being when the walls are made directly with the mud mixture, and the other being walls built by stacking air-dried building blocks called mud bricks.
Wet-laid, or damp, walls are made by using the mud or clay mixture directly without forming blocks and drying them first. The amount of and type of each material in the mixture used leads to different styles of buildings. The deciding factor is usually connected with the quality of the soil being used. Larger amounts of clay are usually employed in building with cob, while low-clay soil is usually associated with sod house or sod roof construction. The other main ingredients include more or less sand/gravel and straw/grasses. Rammed earth is both an old and newer take on creating walls, once made by compacting clay soils between planks by hand; nowadays forms and mechanical pneumatic compressors are used.[7]
Soil, and especially clay, provides good thermal mass; it is very good at keeping temperatures at a constant level. Homes built with earth tend to be naturally cool in the summer heat and warm in cold weather. Clay holds heat or cold, releasing it over a period of time like stone. Earthen walls change temperature slowly, so artificially raising or lowering the temperature can use more resources than in say a wood built house, but the heat/coolness stays longer.[7]
People building with mostly dirt and clay, such as cob, sod, and adobe, created homes that have been built for centuries in western and northern Europe, Asia, as well as the rest of the world, and continue to be built, though on a smaller scale. Some of these buildings have remained habitable for hundreds of years.[8][9]
Mud-bricks, also known by their Spanish name adobe are ancient building materials with evidence dating back thousands of years BC. Compressed earth blocks are a more modern type of brick used for building more frequently in industrialized society since the building blocks can be manufactured off site in a centralized location at a brickworks and transported to multiple building locations. These blocks can also be monetized more easily and sold.
Structural mud bricks are almost always made using clay, often clay soil and a binder are the only ingredients used, but other ingredients can include sand, lime, concrete, stone and other binders. The formed or compressed block is then air dried and can be laid dry or with a mortar or clay slip.
Sand is used with cement, and sometimes lime, to make mortar for masonry work and plaster. Sand is also used as a part of the concrete mix. An important low-cost building material in countries with high sand content soils is the Sandcrete block, which is weaker but cheaper than fired clay bricks.[10]
Rock structures have existed for as long as history can recall. It is the longest-lasting building material available, and is usually readily available. There are many types of rock, with differing attributes that make them better or worse for particular uses. Rock is a very dense material so it gives a lot of protection; its main drawback as a building material is its weight and the difficulty of working it. Its energy density is both an advantage and disadvantage. Stone is hard to warm without consuming considerable energy but, once warm, its thermal mass means that can retain heat for useful periods of time.[11]
Dry-stone walls have been built for as long as humans have put one stone on top of another. Eventually, different forms of mortar were used to hold the stones together, cement being the most commonplace now.
The granite-strewn uplands of Dartmoor National Park, United Kingdom, for example, provided ample resources for early settlers. Circular huts were constructed from loose granite rocks throughout the Neolithic and early Bronze Age, and the remains of an estimated 5,000 can still be seen today. Granite continued to be used throughout the Medieval period (see Dartmoor longhouse) and into modern times. Slate is another stone type, commonly used as roofing material in the United Kingdom and other parts of the world where it is found.
Stone buildings can be seen in most major cities, and some civilizations built predominantly with stone, such as the Egyptian and Aztec pyramids and the structures of the Inca civilization.
Thatch is one of the oldest of building materials known, Thatch is another word for grass; grass is a good insulator and easily harvested. Many African tribes have lived in homes made completely of grasses and sand year-round. In Europe, thatch roofs on homes were once prevalent but the material fell out of favor as industrialization and improved transport increased the availability of other materials. Today, though, the practice is undergoing a revival. In the Netherlands, for instance, many new buildings have thatched roofs with special ridge tiles on top.
Wood has been used as a building material for thousands of years in its natural state. Today, engineered wood is becoming very common in industrialized countries.
Wood is a product of trees, and sometimes other fibrous plants, used for construction purposes when cut or pressed into lumber and timber, such as boards, planks and similar materials. It is a generic building material and is used in building just about any type of structure in most climates. Wood can be very flexible under loads, keeping strength while bending, and is incredibly strong when compressed vertically. There are many differing qualities to the different types of wood, even among same tree species. This means specific species are better suited for various uses than others. And growing conditions are important for deciding quality.
In modern times softwood is used as a lower-value bulk material, whereas hardwood is usually used for finishings and furniture. Historically timber frame structures were built with oak in western Europe, recently douglas fir has become the most popular wood for most types of structural building.
Many families or communities, in rural areas, have a personal woodlot from which the family or community will grow and harvest trees to build with or sell. These lots are tended to like a garden. This was much more prevalent in pre-industrial times, when laws existed as to the amount of wood one could cut at any one time to ensure there would be a supply of timber for the future, but is still a viable form of agriculture.
Clay blocks (sometimes called clay block brick) being laid with an adhesive rather than mortar
Bricks are made in a similar way to mud-bricks except without the fibrous binder such as straw and are fired ("burned" in a brick clamp or kiln) after they have air-dried to permanently harden them. Kiln fired clay bricks are a ceramic material. Fired bricks can be solid or have hollow cavities to aid in drying and make them lighter and easier to transport. The individual bricks are placed upon each other in courses using mortar. Successive courses being used to build up walls, arches, and other architectural elements. Fired brick walls are usually substantially thinner than cob/adobe while keeping the same vertical strength. They require more energy to create but are easier to transport and store, and are lighter than stone blocks. Romans extensively used fired brick of a shape and type now called Roman bricks.[12] Building with brick gained much popularity in the mid-18th century and 19th centuries. This was due to lower costs with increases in brick [13] manufacturing and fire-safety in the ever crowding cities.
The cinder block supplemented or replaced fired bricks in the late 20th century often being used for the inner parts of masonry walls and by themselves.
Cement bonded composites are made of hydrated cement paste that binds wood, particles, or fibers to make pre-cast building components. Various fiberous materials, including paper, fiberglass, and carbon-fiber have been used as binders.
Wood and natural fibers are composed of various soluble organic compounds like carbohydrates, glycosides and phenolics. These compounds are known to retard cement setting. Therefore, before using a wood in making cement bonded composites, its compatibility with cement is assessed.
Wood-cement compatibility is the ratio of a parameter related to the property of a wood-cement composite to that of a neat cement paste. The compatibility is often expressed as a percentage value. To determine wood-cement compatibility, methods based on different properties are used, such as, hydration characteristics, strength, interfacial bond and morphology. Various methods are used by researchers such as the measurement of hydration characteristics of a cement-aggregate mix;[14][15][16] the comparison of the mechanical properties of cement-aggregate mixes[17][18] and the visual assessment of microstructural properties of the wood-cement mixes.[19] It has been found that the hydration test by measuring the change in hydration temperature with time is the most convenient method. Recently, Karade et al.[20] have reviewed these methods of compatibility assessment and suggested a method based on the maturity concept i.e. taking in consideration both time and temperature of cement hydration reaction.
Bricks were laid in lime mortar from the time of the Romans until supplanted by Portland cement mortar in the early 20th century. Cement blocks also sometimes are filled with grout or covered with a parge coat.
Concrete is a composite building material made from the combination of aggregate and a binder such as cement. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generally gravel and sand), portland cement and water.
After mixing, the cement hydrates and eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term "concrete".
For a concrete construction of any size, as concrete has a rather low tensile strength, it is generally strengthened using steel rods or bars (known as rebars). This strengthened concrete is then referred to as reinforced concrete. In order to minimise any air bubbles, that would weaken the structure, a vibrator is used to eliminate any air that has been entrained when the liquid concrete mix is poured around the ironwork. Concrete has been the predominant building material in the modern age due to its longevity, formability, and ease of transport. Recent advancements, such as insulating concrete forms, combine the concrete forming and other construction steps (installation of insulation). All materials must be taken in required proportions as described in standards.
The tent is the home of choice among nomadic groups all over the world. Two well-known types include the conical teepee and the circular yurt. The tent has been revived as a major construction technique with the development of tensile architecture and synthetic fabrics. Modern buildings can be made of flexible material such as fabric membranes, and supported by a system of steel cables, rigid or internal, or by air pressure.
Recently, synthetic polystyrene or polyurethane foam has been used in combination with structural materials, such as concrete. It is lightweight, easily shaped, and an excellent insulator. Foam is usually used as part of a structural insulated panel, wherein the foam is sandwiched between wood or cement or insulating concrete forms.
Glassmaking is considered an art form as well as an industrial process or material.
Clear windows have been used since the invention of glass to cover small openings in a building. Glass panes provided humans with the ability to both let light into rooms while at the same time keeping inclement weather outside.
Glass is generally made from mixtures of sand and silicates, in a very hot fire stove called a kiln, and is very brittle. Additives are often included the mixture used to produce glass with shades of colors or various characteristics (such as bulletproof glass or lightbulbs).
The use of glass in architectural buildings has become very popular in the modern culture. Glass "curtain walls" can be used to cover the entire facade of a building, or it can be used to span over a wide roof structure in a "space frame". These uses though require some sort of frame to hold sections of glass together, as glass by itself is too brittle and would require an overly large kiln to be used to span such large areas by itself.
Glass bricks were invented in the early 20th century.
Gypsum concrete is a mixture of gypsum plaster and fibreglass rovings. Although plaster and fibres fibrous plaster have been used for many years, especially for ceilings, it was not until the early 1990s that serious studies of the strength and qualities of a walling system Rapidwall, using a mixture of gypsum plaster and 300mm plus fibreglass rovings, were investigated. It was discovered, through testing at the University of Adelaide, that these walls had significant, load bearing, shear and lateral resistance together with earthquake-resistance, fire-resistance, and thermal properties. With an abundance of gypsum (naturally occurring and by-product chemical FGD and phospho gypsums) available worldwide, Gypsum concrete-based building products, which are fully recyclable, offer significant environmental benefits.
Metal is used as structural framework for larger buildings such as skyscrapers, or as an external surface covering. There are many types of metals used for building. Metal figures quite prominently in prefabricated structures such as the Quonset hut, and can be seen used in most cosmopolitan cities. It requires a great deal of human labor to produce metal, especially in the large amounts needed for the building industries. Corrosion is metal's prime enemy when it comes to longevity.
Steel is a metal alloy whose major component is iron, and is the usual choice for metal structural building materials. It is strong, flexible, and if refined well and/or treated lasts a long time.
Copper is a valued building material because of its advantageous properties (see: Copper in architecture). These include corrosion resistance, durability, low thermal movement, light weight, radio frequency shielding, lightning protection, sustainability, recyclability, and a wide range of finishes. Copper is incorporated into roofing, flashing, gutters, downspouts, domes, spires, vaults, wall cladding, building expansion joints, and indoor design elements.
Other metals used include chrome, gold, silver, and titanium. Titanium can be used for structural purposes, but it is much more expensive than steel. Chrome, gold, and silver are used as decoration, because these materials are expensive and lack structural qualities such as tensile strength or hardness.
Plastic pipes penetrating a concrete floor in a Canadian highrise apartment building
The term plastics covers a range of synthetic or semi-synthetic organic condensation or polymerization products that can be molded or extruded into objects, films, or fibers. Their name is derived from the fact that in their semi-liquid state they are malleable, or have the property of plasticity. Plastics vary immensely in heat tolerance, hardness, and resiliency. Combined with this adaptability, the general uniformity of composition and lightness of plastics ensures their use in almost all industrial applications today. High performance plastics such as ETFE have become an ideal building material due to its high abrasion resistance and chemical inertness. Notable buildings that feature it include: the Beijing National Aquatics Center and the Eden Project biomes.[21]
Building papers and membranes are used for many reasons in construction. One of the oldest building papers is red rosin paper which was known to be in use before 1850 and was used as an underlayment in exterior walls, roofs, and floors and for protecting a jobsite during construction. Tar paper was invented late in the 19th century and was used for similar purposes as rosin paper and for gravel roofs. Tar paper has largely fallen out of use supplanted by asphalt felt paper. Felt paper has been supplanted in some uses by synthetic underlayments, particularly in roofing by synthetic underlayments and siding by housewraps.
Fired clay bricks have been used since the time of the Romans. Special tiles are used for roofing, siding, flooring, ceilings, pipes, flue liners, and more.
A relatively new category of building materials, living building materials are materials that are either composed of, or created by a living organism; or materials that behave in a manner that's reminiscent of such. Potential use cases include self-healing materials, and materials that replicate (reproduce) rather than be manufactured.
In the market place, the term "building products" often refers to ready-made particles or sections made from various materials, that are fitted in architectural hardware and decorative hardware parts of a building. The list of building products excludes the building materials used to construct the building architecture and supporting fixtures, like windows, doors, cabinets, millwork components, etc. Building products, rather, support and make building materials work in a modular fashion.
"Building products" may also refer to items used to put such hardware together, such as caulking, glues, paint, and anything else bought for the purpose of constructing a building.
In 2017, the buildings and construction together consumed 36% of the final energy produced globally while being responsible for 39% of the global energy related CO2 emissions.[22] The shares from construction industry alone were 6% and 11% respectively. Energy consumption during the building-material production, predominantly due to their use of electricity, is a dominant contributor to the construction industry's share. Embodied energy of relevant building materials in the US are provided in the table below.
ETL SEMKO Building Product Testing Laboratory in the USA, part of Intertek, based in London
^ Nabokov, Peter, and Robert Easton. Native American architecture. New York: Oxford University Press, 1989. 16. Print.
^ Kent, Susan. Domestic architecture and the use of space: an interdisciplinary cross-cultural study. Cambridge, England: Cambridge University Press, 1990. 131.Print.
^ Shaffer, Gary D. (Spring 1993). "An Archaeomagnetic Study of a Wattle and Daub Building Collapse". Journal of Field Archaeology. 20 (1): 5975. JSTOR 530354.
^ Lyon, G. F.. The private journal of Captain G.F. Lyon, of H.M.S. Hecla, during the recent voyage of discovery under Captain Parry .... London: J. Murray, 1824. 280281. Print.
^ Hall, Colin Michael, and Jarkko Saarinen. Tourism and change in polar regions: climate, environments and experiences. Milton Park, Abingdon, Oxon, England: Routledge, 2010. 30. Print.
^ a b McHenry, Paul Graham. Adobe and rammed earth buildings: design and construction. New York: Wiley, 1984. 104. Print.
^ Smith, Michael G. "Cob Building, Ancient and Modern," in Kennedy, Smith and Wanek, (2002), 132133.
^ [1] Earliest Chinese building brick appeared in Xi'an ()]. takungpao.com (2010-1-28)
^ Sandermann, W. and Kohler, R. (1964) Studies on mineral-bonded wood materials. IV. A short test of the aptitudes of woods for cement-bonded materials. Holzforschung 18, 53:59.
^ Weatherwax, R.C. and Tarkow, H. (1964) Effect of wood on setting of Portland cement. For. Prod. J. 14(12), 567570.
^ Hachmi, M., Moslemi, A.A. and Campbell, A.G. (1990) A new technique to classify the compatibility of wood with cement. Wood Sci. Technol. 24(4), 345354.
^ Hong, Z. and Lee, A.W.C. (1986) Compressive strength of cylindrical samples as an indicator of wood- cement compatibility. For. Prod. J. 36(11/12), 8790.
^ Demirbas, A. and Aslan, A. (1998) Effects of ground hazelnut shell, wood and tea waste on the mechanical properties of cement. Cement Concrete Res. 28(8), 11011104.
^ Ahn, W.Y. and Moslemi, A.A. (1980) SEM examination of wood-Portland cement bonds. Wood Sci .13(2), 7782.
^ Karade SR, Irle M, Maher K (2003) Assessment of wood-cement compatibility: A new approach. Holzforschung, 57: 672680.
^ Dixit, Manish K.; Culp, Charles H.; Fernandez-Solis, Jose L. (2015-02-03). "Embodied Energy of Construction Materials: Integrating Human and Capital Energy into an IO-Based Hybrid Model". Environmental Science & Technology. 49 (3): 19361945. Bibcode:2015EnST...49.1936D. doi:10.1021/es503896v. ISSN 0013-936X. PMID 25561008.
chord - chord1:a feeling or emotion: His story struck a chord of pity in the listeners.
chord1:a feeling or emotion: His story struck a chord of pity in the listeners.
chord2:Geometry. the line segment between two points on a given curve.
chord3:Engineering, Building Trades. a principal member of a truss extending from end to end, usually one of a pair of such members, more or less parallel and connected by a web composed of various compression and tension members.
chord4:Aeronautics. a straight line joining the trailing and leading edges of an airfoil section.
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Origin of chord
Origin of chord - 1
1 - 13501400; Middle English Words nearby chord Definition for chord (2 of 2) / krd /PHONETIC RESPELLING noun a combination of usually three or more musical tones sounded simultaneously. verb (used with object) to establish or play a chord or chords for (a particular harmony or song); harmonize or voice: How would you chord that in B flat? Origin of chord 2 13501400; earlier cord,Middle English, short for accord; ch- from chord1 Words related to chord Example sentences from the Web for chord Music director Felton Offard contributes sharp guitar riffs and bluesy harmonica chords as a one-man backup band, separated from Butler by a plexiglass partition. In the end most teams used smaller models that produced specific parts of a song, like the chords or melodies, and then stitched these together by hand. Cable management grommets keep your desktop free of tangled chords, and waterproof and scratch resistant surfaces can handle any amount of wear. Whats more, Nordstroms reputation for good customer service struck a chord with Smith, whose company is renowned for its generous returns policy. In this years combustible political atmosphere, its uncontroversial purpose has struck a chord. And the chord structure, for those of you who play an instrument, is unexpected and worth checking out. The guitar is tuned to E, and an Eminor chord on a guitar just rings and rings forever. It does strike a chord when you see just how victimizing some of the media reports can be of Africa. But it is based on the chord structure of what I played before it, except that it was based on a diminished scale. In this position, the line of cavalry formed the chord of the arc described by the river, and occupied by us. There is quite a little knack in letting the hand fall so, but when you have once got it, the chord sounds much richer and fuller. When she struck the chord of G minor, it was the right preparation, and brought you immediately into the mood for what followed. It produced comparatively little foundation tone and a powerful chord of harmonics, many of them dissonant. No drooping Clytie could be more constant than I to him who strikes the chord that is responsive in my soul. British Dictionary definitions for chord (1 of 2) / (kd) / noun maths a straight line connecting two points on a curve or curved surface the line segment lying between two points of intersection of a straight line and a curve or curved surface engineering one of the principal members of a truss, esp one that lies along the top or the bottom an emotional response, esp one of sympathythe story struck the right chord an imaginary straight line joining the leading edge and the trailing edge of an aerofoil archaic the string of a musical instrument Derived forms of chord chorded, adjective Word Origin for chord C16: from Latin chorda, from Greek khord gut, string; see cord Cultural definitions for chord chord In music, the sound of three or more notes played at the same time. The history of Western music is marked by an increase in complexity of the chords composers use.
13501400; Middle English
Words nearby chord - Definition for chord (2 of 2)
Definition for chord (2 of 2) - / krd /PHONETIC RESPELLING
/ krd /PHONETIC RESPELLING - noun
noun - a combination of usually three or more musical tones sounded simultaneously.
a combination of usually three or more musical tones sounded simultaneously.
verb (used with object) - to establish or play a chord or chords for (a particular harmony or song); harmonize or voice: How would you chord that in B flat?
to establish or play a chord or chords for (a particular harmony or song); harmonize or voice: How would you chord that in B flat?
Origin of chord - 2
2 - 13501400; earlier cord,Middle English, short for accord; ch- from chord1
13501400; earlier cord,Middle English, short for accord; ch- from chord1
Words related to chord - Example sentences from the Web for chord
Example sentences from the Web for chord - Music director Felton Offard contributes sharp guitar riffs and bluesy harmonica chords as a one-man backup band, separated from Butler by a plexiglass partition.
Music director Felton Offard contributes sharp guitar riffs and bluesy harmonica chords as a one-man backup band, separated from Butler by a plexiglass partition.
In the end most teams used smaller models that produced specific parts of a song, like the chords or melodies, and then stitched these together by hand.
Cable management grommets keep your desktop free of tangled chords, and waterproof and scratch resistant surfaces can handle any amount of wear.
Whats more, Nordstroms reputation for good customer service struck a chord with Smith, whose company is renowned for its generous returns policy.
In this years combustible political atmosphere, its uncontroversial purpose has struck a chord.
And the chord structure, for those of you who play an instrument, is unexpected and worth checking out.
The guitar is tuned to E, and an Eminor chord on a guitar just rings and rings forever.
It does strike a chord when you see just how victimizing some of the media reports can be of Africa.
But it is based on the chord structure of what I played before it, except that it was based on a diminished scale.
In this position, the line of cavalry formed the chord of the arc described by the river, and occupied by us.
There is quite a little knack in letting the hand fall so, but when you have once got it, the chord sounds much richer and fuller.
When she struck the chord of G minor, it was the right preparation, and brought you immediately into the mood for what followed.
It produced comparatively little foundation tone and a powerful chord of harmonics, many of them dissonant.
No drooping Clytie could be more constant than I to him who strikes the chord that is responsive in my soul.
British Dictionary definitions for chord (1 of 2)
/ (kd) / - noun
noun - maths
maths - a straight line connecting two points on a curve or curved surface
a straight line connecting two points on a curve or curved surface
the line segment lying between two points of intersection of a straight line and a curve or curved surface
engineering one of the principal members of a truss, esp one that lies along the top or the bottom
an emotional response, esp one of sympathythe story struck the right chord
an imaginary straight line joining the leading edge and the trailing edge of an aerofoil
archaic the string of a musical instrument - Derived forms of chord
Derived forms of chord - chorded, adjective
chorded, adjective - Word Origin for chord
Word Origin for chord - C16: from Latin chorda, from Greek khord gut, string; see cord
C16: from Latin chorda, from Greek khord gut, string; see cord
Cultural definitions for chord - chord
chord - In music, the sound of three or more notes played at the same time. The history of Western music is marked by an increase in complexity of the chords composers use.
In music, the sound of three or more notes played at the same time. The history of Western music is marked by an increase in complexity of the chords composers use.
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coarse - Coarse can mean rough to the touch or vulgar. It's good to have coarse sand paper, but not good to have coarse manners.
Coarse can mean rough to the touch or vulgar. It's good to have coarse sand paper, but not good to have coarse manners.
Do you lick your dinner plate, wipe your nose on your sleeve, and generally behave like an oaf? No, of course not. You're the kind of person who reads online dictionaries. But if you did do any of things, you'd be coarse that is, unrefined, boorish, and downright vulgar. Coarse can apply to a wide variety of things other than behavior. If something is of poor quality, cheap and inferior, it's considered coarse.
Definitions of coarse - adjective
rough or harsh in textureadjective - of textures that are rough to the touch or substances consisting of relatively large particles
of textures that are rough to the touch or substances consisting of relatively large particles
of textures that are smooth to the touch or substances consisting of relatively small particles
dense or compact in structure or texture, as a wood composed of small-diameter cells
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Color (North American English), or colour (Commonwealth English), is the characteristic of visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of photoreceptor cells (in particular cone cells in the human eye and other vertebrate eyes) by electromagnetic radiation (in the visible spectrum in the case of humans). Color categories and physical specifications of color are associated with objects through the wavelengths of the light that is reflected from them and their intensities. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc.
Colors can appear different depending on their surrounding colors and shapes. In this optical illusion, the two small squares have exactly the same color, but the right one looks slightly darker.
By defining a color space, colors can be identified numerically by coordinates, which in 1931 were also named in global agreement with internationally agreed color names like mentioned above (red, orange, etc.) by the International Commission on Illumination. The RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564580 nm (red); medium-wavelength, peaking near 534545 nm (green); and short-wavelength light, near 420440 nm (blue).[1][2] There may also be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a color's colorfulness).
The photo-receptivity of the "eyes" of other species also varies considerably from that of humans and so results in correspondingly different color perceptions that cannot readily be compared to one another. Honey bees and bumblebees have trichromatic color vision sensitive to ultraviolet but insensitive to red. Papilio butterflies possess six types of photoreceptors and may have pentachromatic vision.[3] The most complex color vision system in the animal kingdom has been found in stomatopods (such as the mantis shrimp) with up to 12 spectral receptor types thought to work as multiple dichromatic units.[4]
The science of color is sometimes called chromatics, colorimetry, or simply color science. It includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (that is, what is commonly referred to simply as light).
Most light sources emit light at many different wavelengths; a source's spectrum is a distribution giving its intensity at each wavelength. Although the spectrum of light arriving at the eye from a given direction determines the color sensation in that direction, there are many more possible spectral combinations than color sensations. In fact, one may formally define a color as a class of spectra that give rise to the same color sensation, although such classes would vary widely among different species, and to a lesser extent among individuals within the same species. In each such class the members are called metamers of the color in question. This effect can be visualized by comparing the light sources' spectral power distributions and the resulting colors.
Spectral colors - The familiar colors of the rainbow in the spectrumnamed using the Latin word for appearance or apparition by Isaac Newton in 1671include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate frequencies (in terahertz) and wavelengths (in nanometers) for various pure spectral colors. The wavelengths listed are as measured in air or vacuum (see refractive index).
The familiar colors of the rainbow in the spectrumnamed using the Latin word for appearance or apparition by Isaac Newton in 1671include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate frequencies (in terahertz) and wavelengths (in nanometers) for various pure spectral colors. The wavelengths listed are as measured in air or vacuum (see refractive index).
The color table should not be interpreted as a definitive listthe pure spectral colors form a continuous spectrum, and how it is divided into distinct colors linguistically is a matter of culture and historical contingency (although people everywhere have been shown to perceive colors in the same way[6]). A common list identifies six main bands: red, orange, yellow, green, blue, and violet. Newton's conception included a seventh color, indigo, between blue and violet. It is possible that what Newton referred to as blue is nearer to what today is known as cyan, and that indigo was simply the dark blue of the indigo dye that was being imported at the time.[7]
The intensity of a spectral color, relative to the context in which it is viewed, may alter its perception considerably; for example, a low-intensity orange-yellow is brown, and a low-intensity yellow-green is olive green.
Color of objects - The color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which normally depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as potentially on the angles of illumination and viewing. Some objects not only reflect light, but also transmit light or emit light themselves, which also contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but also on a host of contextual cues, so that color differences between objects can be discerned mostly independent of the lighting spectrum, viewing angle, etc. This effect is known as color constancy.
The color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which normally depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as potentially on the angles of illumination and viewing. Some objects not only reflect light, but also transmit light or emit light themselves, which also contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but also on a host of contextual cues, so that color differences between objects can be discerned mostly independent of the lighting spectrum, viewing angle, etc. This effect is known as color constancy.
The upper disk and the lower disk have exactly the same objective color, and are in identical gray surroundings; based on context differences, humans perceive the squares as having different reflectances, and may interpret the colors as different color categories; see checker shadow illusion.
Some generalizations of the physics can be drawn, neglecting perceptual effects for now:
Light arriving at an opaque surface is either reflected "specularly" (that is, in the manner of a mirror), scattered (that is, reflected with diffuse scattering), or absorbedor some combination of these.
Opaque objects that do not reflect specularly (which tend to have rough surfaces) have their color determined by which wavelengths of light they scatter strongly (with the light that is not scattered being absorbed). If objects scatter all wavelengths with roughly equal strength, they appear white. If they absorb all wavelengths, they appear black.[8]
Opaque objects that specularly reflect light of different wavelengths with different efficiencies look like mirrors tinted with colors determined by those differences. An object that reflects some fraction of impinging light and absorbs the rest may look black but also be faintly reflective; examples are black objects coated with layers of enamel or lacquer.
Objects that transmit light are either translucent (scattering the transmitted light) or transparent (not scattering the transmitted light). If they also absorb (or reflect) light of various wavelengths differentially, they appear tinted with a color determined by the nature of that absorption (or that reflectance).
Objects may emit light that they generate from having excited electrons, rather than merely reflecting or transmitting light. The electrons may be excited due to elevated temperature (incandescence), as a result of chemical reactions (chemiluminescence), after absorbing light of other frequencies ("fluorescence" or "phosphorescence") or from electrical contacts as in light-emitting diodes, or other light sources.
To summarize, the color of an object is a complex result of its surface properties, its transmission properties, and its emission properties, all of which contribute to the mix of wavelengths in the light leaving the surface of the object. The perceived color is then further conditioned by the nature of the ambient illumination, and by the color properties of other objects nearby, and via other characteristics of the perceiving eye and brain.
Perception - When viewed in full size, this image contains about 16 million pixels, each corresponding to a different color on the full set of RGB colors. The human eye can distinguish about 10 million different colors.[9]
When viewed in full size, this image contains about 16 million pixels, each corresponding to a different color on the full set of RGB colors. The human eye can distinguish about 10 million different colors.[9]
Development of theories of color vision - Although Aristotle and other ancient scientists had already written on the nature of light and color vision, it was not until Newton that light was identified as the source of the color sensation. In 1810, Goethe published his comprehensive Theory of Colors in which he ascribed physiological effects to color that are now understood as psychological.
Although Aristotle and other ancient scientists had already written on the nature of light and color vision, it was not until Newton that light was identified as the source of the color sensation. In 1810, Goethe published his comprehensive Theory of Colors in which he ascribed physiological effects to color that are now understood as psychological.
In 1801 Thomas Young proposed his trichromatic theory, based on the observation that any color could be matched with a combination of three lights. This theory was later refined by James Clerk Maxwell and Hermann von Helmholtz. As Helmholtz puts it, "the principles of Newton's law of mixture were experimentally confirmed by Maxwell in 1856. Young's theory of color sensations, like so much else that this marvelous investigator achieved in advance of his time, remained unnoticed until Maxwell directed attention to it."[10]
At the same time as Helmholtz, Ewald Hering developed the opponent process theory of color, noting that color blindness and afterimages typically come in opponent pairs (red-green, blue-orange, yellow-violet, and black-white). Ultimately these two theories were synthesized in 1957 by Hurvich and Jameson, who showed that retinal processing corresponds to the trichromatic theory, while processing at the level of the lateral geniculate nucleus corresponds to the opponent theory.[11]
In 1931, an international group of experts known as the Commission internationale de l'clairage (CIE) developed a mathematical color model, which mapped out the space of observable colors and assigned a set of three numbers to each.
Color in the eye - Normalized typical human cone cell responses (S, M, and L types) to monochromatic spectral stimuli
Normalized typical human cone cell responses (S, M, and L types) to monochromatic spectral stimuli
The ability of the human eye to distinguish colors is based upon the varying sensitivity of different cells in the retina to light of different wavelengths. Humans are trichromaticthe retina contains three types of color receptor cells, or cones. One type, relatively distinct from the other two, is most responsive to light that is perceived as blue or blue-violet, with wavelengths around 450 nm; cones of this type are sometimes called short-wavelength cones or S cones (or misleadingly, blue cones). The other two types are closely related genetically and chemically: middle-wavelength cones, M cones, or green cones are most sensitive to light perceived as green, with wavelengths around 540 nm, while the long-wavelength cones, L cones, or red cones, are most sensitive to light that is perceived as greenish yellow, with wavelengths around 570 nm.
Light, no matter how complex its composition of wavelengths, is reduced to three color components by the eye. Each cone type adheres to the principle of univariance, which is that each cone's output is determined by the amount of light that falls on it over all wavelengths. For each location in the visual field, the three types of cones yield three signals based on the extent to which each is stimulated. These amounts of stimulation are sometimes called tristimulus values.
The response curve as a function of wavelength varies for each type of cone. Because the curves overlap, some tristimulus values do not occur for any incoming light combination. For example, it is not possible to stimulate only the mid-wavelength (so-called "green") cones; the other cones will inevitably be stimulated to some degree at the same time. The set of all possible tristimulus values determines the human color space. It has been estimated that humans can distinguish roughly 10 million different colors.[9]
The other type of light-sensitive cell in the eye, the rod, has a different response curve. In normal situations, when light is bright enough to strongly stimulate the cones, rods play virtually no role in vision at all.[12] On the other hand, in dim light, the cones are understimulated leaving only the signal from the rods, resulting in a colorless response. (Furthermore, the rods are barely sensitive to light in the "red" range.) In certain conditions of intermediate illumination, the rod response and a weak cone response can together result in color discriminations not accounted for by cone responses alone. These effects, combined, are summarized also in the Kruithof curve, that describes the change of color perception and pleasingness of light as function of temperature and intensity.
Color in the brain - The visual dorsal stream (green) and ventral stream (purple) are shown. The ventral stream is responsible for color perception.
The visual dorsal stream (green) and ventral stream (purple) are shown. The ventral stream is responsible for color perception.
While the mechanisms of color vision at the level of the retina are well-described in terms of tristimulus values, color processing after that point is organized differently. A dominant theory of color vision proposes that color information is transmitted out of the eye by three opponent processes, or opponent channels, each constructed from the raw output of the cones: a redgreen channel, a blueyellow channel, and a blackwhite "luminance" channel. This theory has been supported by neurobiology, and accounts for the structure of our subjective color experience. Specifically, it explains why humans cannot perceive a "reddish green" or "yellowish blue", and it predicts the color wheel: it is the collection of colors for which at least one of the two color channels measures a value at one of its extremes.
The exact nature of color perception beyond the processing already described, and indeed the status of color as a feature of the perceived world or rather as a feature of our perception of the worlda type of qualiais a matter of complex and continuing philosophical dispute.
Nonstandard color perception - Color deficiency
Color deficiency - If one or more types of a person's color-sensing cones are missing or less responsive than normal to incoming light, that person can distinguish fewer colors and is said to be color deficient or color blind (though this latter term can be misleading; almost all color deficient individuals can distinguish at least some colors). Some kinds of color deficiency are caused by anomalies in the number or nature of cones in the retina. Others (like central or cortical achromatopsia) are caused by neural anomalies in those parts of the brain where visual processing takes place.
If one or more types of a person's color-sensing cones are missing or less responsive than normal to incoming light, that person can distinguish fewer colors and is said to be color deficient or color blind (though this latter term can be misleading; almost all color deficient individuals can distinguish at least some colors). Some kinds of color deficiency are caused by anomalies in the number or nature of cones in the retina. Others (like central or cortical achromatopsia) are caused by neural anomalies in those parts of the brain where visual processing takes place.
Tetrachromacy - While most humans are trichromatic (having three types of color receptors), many animals, known as tetrachromats, have four types. These include some species of spiders, most marsupials, birds, reptiles, and many species of fish. Other species are sensitive to only two axes of color or do not perceive color at all; these are called dichromats and monochromats respectively. A distinction is made between retinal tetrachromacy (having four pigments in cone cells in the retina, compared to three in trichromats) and functional tetrachromacy (having the ability to make enhanced color discriminations based on that retinal difference). As many as half of all women are retinal tetrachromats.[13]:p.256 The phenomenon arises when an individual receives two slightly different copies of the gene for either the medium- or long-wavelength cones, which are carried on the X chromosome. To have two different genes, a person must have two X chromosomes, which is why the phenomenon only occurs in women.[13] There is one scholarly report that confirms the existence of a functional tetrachromat.[14]
While most humans are trichromatic (having three types of color receptors), many animals, known as tetrachromats, have four types. These include some species of spiders, most marsupials, birds, reptiles, and many species of fish. Other species are sensitive to only two axes of color or do not perceive color at all; these are called dichromats and monochromats respectively. A distinction is made between retinal tetrachromacy (having four pigments in cone cells in the retina, compared to three in trichromats) and functional tetrachromacy (having the ability to make enhanced color discriminations based on that retinal difference). As many as half of all women are retinal tetrachromats.[13]:p.256 The phenomenon arises when an individual receives two slightly different copies of the gene for either the medium- or long-wavelength cones, which are carried on the X chromosome. To have two different genes, a person must have two X chromosomes, which is why the phenomenon only occurs in women.[13] There is one scholarly report that confirms the existence of a functional tetrachromat.[14]
Synesthesia - In certain forms of synesthesia/ideasthesia, perceiving letters and numbers (graphemecolor synesthesia) or hearing musical sounds (musiccolor synesthesia) will lead to the unusual additional experiences of seeing colors. Behavioral and functional neuroimaging experiments have demonstrated that these color experiences lead to changes in behavioral tasks and lead to increased activation of brain regions involved in color perception, thus demonstrating their reality, and similarity to real color percepts, albeit evoked through a non-standard route.
In certain forms of synesthesia/ideasthesia, perceiving letters and numbers (graphemecolor synesthesia) or hearing musical sounds (musiccolor synesthesia) will lead to the unusual additional experiences of seeing colors. Behavioral and functional neuroimaging experiments have demonstrated that these color experiences lead to changes in behavioral tasks and lead to increased activation of brain regions involved in color perception, thus demonstrating their reality, and similarity to real color percepts, albeit evoked through a non-standard route.
Afterimages - After exposure to strong light in their sensitivity range, photoreceptors of a given type become desensitized. For a few seconds after the light ceases, they will continue to signal less strongly than they otherwise would. Colors observed during that period will appear to lack the color component detected by the desensitized photoreceptors. This effect is responsible for the phenomenon of afterimages, in which the eye may continue to see a bright figure after looking away from it, but in a complementary color.
After exposure to strong light in their sensitivity range, photoreceptors of a given type become desensitized. For a few seconds after the light ceases, they will continue to signal less strongly than they otherwise would. Colors observed during that period will appear to lack the color component detected by the desensitized photoreceptors. This effect is responsible for the phenomenon of afterimages, in which the eye may continue to see a bright figure after looking away from it, but in a complementary color.
Afterimage effects have also been utilized by artists, including Vincent van Gogh.
Color constancy - When an artist uses a limited color palette, the human eye tends to compensate by seeing any gray or neutral color as the color which is missing from the color wheel. For example, in a limited palette consisting of red, yellow, black, and white, a mixture of yellow and black will appear as a variety of green, a mixture of red and black will appear as a variety of purple, and pure gray will appear bluish.[15]
When an artist uses a limited color palette, the human eye tends to compensate by seeing any gray or neutral color as the color which is missing from the color wheel. For example, in a limited palette consisting of red, yellow, black, and white, a mixture of yellow and black will appear as a variety of green, a mixture of red and black will appear as a variety of purple, and pure gray will appear bluish.[15]
The trichromatic theory is strictly true when the visual system is in a fixed state of adaptation. In reality, the visual system is constantly adapting to changes in the environment and compares the various colors in a scene to reduce the effects of the illumination. If a scene is illuminated with one light, and then with another, as long as the difference between the light sources stays within a reasonable range, the colors in the scene appear relatively constant to us. This was studied by Edwin H. Land in the 1970s and led to his retinex theory of color constancy.
Both phenomena are readily explained and mathematically modeled with modern theories of chromatic adaptation and color appearance (e.g. CIECAM02, iCAM).[16] There is no need to dismiss the trichromatic theory of vision, but rather it can be enhanced with an understanding of how the visual system adapts to changes in the viewing environment.
Color naming - This picture contains one million pixels, each one a different color
This picture contains one million pixels, each one a different color
Colors vary in several different ways, including hue (shades of red, orange, yellow, green, blue, and violet), saturation, brightness, and gloss. Some color words are derived from the name of an object of that color, such as "orange" or "salmon", while others are abstract, like "red".
In the 1969 study Basic Color Terms: Their Universality and Evolution, Brent Berlin and Paul Kay describe a pattern in naming "basic" colors (like "red" but not "red-orange" or "dark red" or "blood red", which are "shades" of red). All languages that have two "basic" color names distinguish dark/cool colors from bright/warm colors. The next colors to be distinguished are usually red and then yellow or green. All languages with six "basic" colors include black, white, red, green, blue, and yellow. The pattern holds up to a set of twelve: black, gray, white, pink, red, orange, yellow, green, blue, purple, brown, and azure (distinct from blue in Russian and Italian, but not English).
In culture - Colors, their meanings and associations can play major role in works of art, including literature.[17]
Colors, their meanings and associations can play major role in works of art, including literature.[17]
Associations - Individual colors have a variety of cultural associations such as national colors (in general described in individual color articles and color symbolism). The field of color psychology attempts to identify the effects of color on human emotion and activity. Chromotherapy is a form of alternative medicine attributed to various Eastern traditions. Colors have different associations in different countries and cultures.[18]
Individual colors have a variety of cultural associations such as national colors (in general described in individual color articles and color symbolism). The field of color psychology attempts to identify the effects of color on human emotion and activity. Chromotherapy is a form of alternative medicine attributed to various Eastern traditions. Colors have different associations in different countries and cultures.[18]
Different colors have been demonstrated to have effects on cognition. For example, researchers at the University of Linz in Austria demonstrated that the color red significantly decreases cognitive functioning in men.[19]
Spectral colors and color reproduction - The CIE 1931 color space chromaticity diagram. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers. The colors depicted depend on the color space of the device on which you are viewing the image, and therefore may not be a strictly accurate representation of the color at a particular position, and especially not for monochromatic colors.
The CIE 1931 color space chromaticity diagram. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers. The colors depicted depend on the color space of the device on which you are viewing the image, and therefore may not be a strictly accurate representation of the color at a particular position, and especially not for monochromatic colors.
Most light sources are mixtures of various wavelengths of light. Many such sources can still effectively produce a spectral color, as the eye cannot distinguish them from single-wavelength sources. For example, most computer displays reproduce the spectral color orange as a combination of red and green light; it appears orange because the red and green are mixed in the right proportions to allow the eye's cones to respond the way they do to the spectral color orange.
A useful concept in understanding the perceived color of a non-monochromatic light source is the dominant wavelength, which identifies the single wavelength of light that produces a sensation most similar to the light source. Dominant wavelength is roughly akin to hue.
There are many color perceptions that by definition cannot be pure spectral colors due to desaturation or because they are purples (mixtures of red and violet light, from opposite ends of the spectrum). Some examples of necessarily non-spectral colors are the achromatic colors (black, gray, and white) and colors such as pink, tan, and magenta.
Two different light spectra that have the same effect on the three color receptors in the human eye will be perceived as the same color. They are metamers of that color. This is exemplified by the white light emitted by fluorescent lamps, which typically has a spectrum of a few narrow bands, while daylight has a continuous spectrum. The human eye cannot tell the difference between such light spectra just by looking into the light source, although reflected colors from objects can look different. (This is often exploited; for example, to make fruit or tomatoes look more intensely red.)
Similarly, most human color perceptions can be generated by a mixture of three colors called primaries. This is used to reproduce color scenes in photography, printing, television, and other media. There are a number of methods or color spaces for specifying a color in terms of three particular primary colors. Each method has its advantages and disadvantages depending on the particular application.
No mixture of colors, however, can produce a response truly identical to that of a spectral color, although one can get close, especially for the longer wavelengths, where the CIE 1931 color space chromaticity diagram has a nearly straight edge. For example, mixing green light (530 nm) and blue light (460 nm) produces cyan light that is slightly desaturated, because response of the red color receptor would be greater to the green and blue light in the mixture than it would be to a pure cyan light at 485 nm that has the same intensity as the mixture of blue and green.
Because of this, and because the primaries in color printing systems generally are not pure themselves, the colors reproduced are never perfectly saturated spectral colors, and so spectral colors cannot be matched exactly. However, natural scenes rarely contain fully saturated colors, thus such scenes can usually be approximated well by these systems. The range of colors that can be reproduced with a given color reproduction system is called the gamut. The CIE chromaticity diagram can be used to describe the gamut.
Another problem with color reproduction systems is connected with the acquisition devices, like cameras or scanners. The characteristics of the color sensors in the devices are often very far from the characteristics of the receptors in the human eye. In effect, acquisition of colors can be relatively poor if they have special, often very "jagged", spectra caused for example by unusual lighting of the photographed scene. A color reproduction system "tuned" to a human with normal color vision may give very inaccurate results for other observers.
The different color response of different devices can be problematic if not properly managed. For color information stored and transferred in digital form, color management techniques, such as those based on ICC profiles, can help to avoid distortions of the reproduced colors. Color management does not circumvent the gamut limitations of particular output devices, but can assist in finding good mapping of input colors into the gamut that can be reproduced.
Additive coloring - Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.
Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.
Additive color is light created by mixing together light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color systems such as projectors and computer terminals.
Subtractive coloring - Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black
Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black
Twelve main pigment colors - Subtractive coloring uses dyes, inks, pigments, or filters to absorb some wavelengths of light and not others. The color that a surface displays comes from the parts of the visible spectrum that are not absorbed and therefore remain visible. Without pigments or dye, fabric fibers, paint base and paper are usually made of particles that scatter white light (all colors) well in all directions. When a pigment or ink is added, wavelengths are absorbed or "subtracted" from white light, so light of another color reaches the eye.
Subtractive coloring uses dyes, inks, pigments, or filters to absorb some wavelengths of light and not others. The color that a surface displays comes from the parts of the visible spectrum that are not absorbed and therefore remain visible. Without pigments or dye, fabric fibers, paint base and paper are usually made of particles that scatter white light (all colors) well in all directions. When a pigment or ink is added, wavelengths are absorbed or "subtracted" from white light, so light of another color reaches the eye.
If the light is not a pure white source (the case of nearly all forms of artificial lighting), the resulting spectrum will appear a slightly different color. Red paint, viewed under blue light, may appear black. Red paint is red because it scatters only the red components of the spectrum. If red paint is illuminated by blue light, it will be absorbed by the red paint, creating the appearance of a black object.
Structural color - Structural colors are colors caused by interference effects rather than by pigments. Color effects are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the color's wavelength. If the microstructures are spaced randomly, light of shorter wavelengths will be scattered preferentially to produce Tyndall effect colors: the blue of the sky (Rayleigh scattering, caused by structures much smaller than the wavelength of light, in this case air molecules), the luster of opals, and the blue of human irises. If the microstructures are aligned in arrays, for example the array of pits in a CD, they behave as a diffraction grating: the grating reflects different wavelengths in different directions due to interference phenomena, separating mixed "white" light into light of different wavelengths. If the structure is one or more thin layers then it will reflect some wavelengths and transmit others, depending on the layers' thickness.
Structural colors are colors caused by interference effects rather than by pigments. Color effects are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the color's wavelength. If the microstructures are spaced randomly, light of shorter wavelengths will be scattered preferentially to produce Tyndall effect colors: the blue of the sky (Rayleigh scattering, caused by structures much smaller than the wavelength of light, in this case air molecules), the luster of opals, and the blue of human irises. If the microstructures are aligned in arrays, for example the array of pits in a CD, they behave as a diffraction grating: the grating reflects different wavelengths in different directions due to interference phenomena, separating mixed "white" light into light of different wavelengths. If the structure is one or more thin layers then it will reflect some wavelengths and transmit others, depending on the layers' thickness.
Structural color is studied in the field of thin-film optics. The most ordered or the most changeable structural colors are iridescent. Structural color is responsible for the blues and greens of the feathers of many birds (the blue jay, for example), as well as certain butterfly wings and beetle shells. Variations in the pattern's spacing often give rise to an iridescent effect, as seen in peacock feathers, soap bubbles, films of oil, and mother of pearl, because the reflected color depends upon the viewing angle. Numerous scientists have carried out research in butterfly wings and beetle shells, including Isaac Newton and Robert Hooke. Since 1942, electron micrography has been used, advancing the development of products that exploit structural color, such as "photonic" cosmetics.[20]
Additional terms - Color wheel: an illustrative organization of color hues in a circle that shows relationships.
Color wheel: an illustrative organization of color hues in a circle that shows relationships.
Colorfulness, chroma, purity, or saturation: how "intense" or "concentrated" a color is. Technical definitions distinguish between colorfulness, chroma, and saturation as distinct perceptual attributes and include purity as a physical quantity. These terms, and others related to light and color are internationally agreed upon and published in the CIE Lighting Vocabulary.[21] More readily available texts on colorimetry also define and explain these terms.[16][22]
Dichromatism: a phenomenon where the hue is dependent on concentration and thickness of the absorbing substance.
References - ^ Wyszecki, Gnther; Stiles, W.S. (1982). Colour Science: Concepts and Methods, Quantitative Data and Formulae (2nd ed.). New York: Wiley Series in Pure and Applied Optics. ISBN 978-0-471-02106-3.
^ Wyszecki, Gnther; Stiles, W.S. (1982). Colour Science: Concepts and Methods, Quantitative Data and Formulae (2nd ed.). New York: Wiley Series in Pure and Applied Optics. ISBN 978-0-471-02106-3.
^ Pastoureau, Michael (2008). Black: The History of a Color. Princeton University Press. p. 216. ISBN 978-0691139302.
^ a b Judd, Deane B.; Wyszecki, Gnter (1975). Color in Business, Science and Industry. Wiley Series in Pure and Applied Optics (third ed.). New York: Wiley-Interscience. p. 388. ISBN 978-0-471-45212-6.
^ Hermann von Helmholtz, Physiological Optics: The Sensations of Vision, 1866, as translated in Sources of Color Science, David L. MacAdam, ed., Cambridge: MIT Press, 1970.
^ Palmer, S.E. (1999). Vision Science: Photons to Phenomenology, Cambridge, MA: MIT Press. ISBN 0-262-16183-4.
^ Gnambs, Timo; Appel, Markus; Batinic, Bernad (2010). "Color red in web-based knowledge testing". Computers in Human Behavior. 26 (6): 162531. doi:10.1016/j.chb.2010.06.010.
External links and sources - ColorLab MATLAB toolbox for color science computation and accurate color reproduction (by Jesus Malo and Maria Jose Luque, Universitat de Valencia). It includes CIE standard tristimulus colorimetry and transformations to a number of non-linear color appearance models (CIE Lab, CIE CAM, etc.).
ColorLab MATLAB toolbox for color science computation and accurate color reproduction (by Jesus Malo and Maria Jose Luque, Universitat de Valencia). It includes CIE standard tristimulus colorimetry and transformations to a number of non-linear color appearance models (CIE Lab, CIE CAM, etc.).
Steel/Precast Estimation, Detailing Steel, Precast, Rebar and MEP
What is concrete cover? Why is it important? (Precast)
What is concrete cover? - Cover refers to the distance between the outside of a concrete structure and the reinforcement. Perhaps see this from the diagram below:
Cover refers to the distance between the outside of a concrete structure and the reinforcement. Perhaps see this from the diagram below:
You need to have a minimum cover: - There needs to be a minimal distance between the reinforcement bar and the outside of the panel.
There needs to be a minimal distance between the reinforcement bar and the outside of the panel.
Why do you need this? - Reduces Corrosion
Reduces Corrosion - Having a decent amount of cover reduces the rate of the corrosion of those reinforcement bars. If you have only 5 mm of cover if the bar is literally just below the surface of the concrete, then that reinforcement is going to corrode away very quickly especially if you are close to the sea. This means that the concrete will lose its strength very quickly, and a catastrophic failure might be on the cards. Thats why it is very important that the concrete does indeed have some minimal cover.
Having a decent amount of cover reduces the rate of the corrosion of those reinforcement bars. If you have only 5 mm of cover if the bar is literally just below the surface of the concrete, then that reinforcement is going to corrode away very quickly especially if you are close to the sea. This means that the concrete will lose its strength very quickly, and a catastrophic failure might be on the cards. Thats why it is very important that the concrete does indeed have some minimal cover.
To Improve the Structural Integrity of the Concrete:
If you have the reinforcement bar too close to the concrete, then the structural integrity of the structure will be somewhat compromised.
Fire Protection: - If at all there is a fire, you dont want the reinforcement bars igniting. If it does then the fire is sure to blaze out of control. Thats another reason why its very important that the bars some minimal distance away from the surface of the concrete. That will better enable the structure to remain in tact if at all there is a fire.
If at all there is a fire, you dont want the reinforcement bars igniting. If it does then the fire is sure to blaze out of control. Thats another reason why its very important that the bars some minimal distance away from the surface of the concrete. That will better enable the structure to remain in tact if at all there is a fire.
A Response to a Readers Question: - (Q1) It appears that one of the lapped bar is bent while the other isnt. Or is it just a drawing convention problem?
(Q1) It appears that one of the lapped bar is bent while the other isnt. Or is it just a drawing convention problem?
(Q2) I dont get why the lapped bars have to be positioned differently when placed on the top vs at the bottom in order to ensure that the concrete thickness will not reduce, as stated in the figure. My thought is that both positioning ways occupy the same volume.
The answer to this question is best understood by studying the below diagrams:
The Answers to the Questions - (A1) When I draw reinforcement, I do not add a lot of the essential details which are assumed to be standard workshop practice. We are required to maintain a minimum cover. The diagram you have posted above is an example of what actually occurs in practice (but is almost never drawn that way). The reason it is bent is to ensure that the minimum cover requirements are not compromised.
(A1) When I draw reinforcement, I do not add a lot of the essential details which are assumed to be standard workshop practice. We are required to maintain a minimum cover. The diagram you have posted above is an example of what actually occurs in practice (but is almost never drawn that way). The reason it is bent is to ensure that the minimum cover requirements are not compromised.
(A2) That is absolutely correct the panels thickness will not be reduced, but the thickness of the cover will change, depending on how one places the reo (reinforcement) rods.
Related - 7 thoughts on What is concrete cover? Why is it important? (Precast)
7 thoughts on What is concrete cover? Why is it important? (Precast)
Very nice and comprehensive explanation! It clears up my doubts. Thank you so much!
I now understand that by bending a reinforcement gives us an easy reference for maintaining the required cover distance. Yet, just one follow-up question-maybe a too detailed one-will bending the bars create some weak points in the bar so it becomes unsafe?
I also notice the fact that the lapped part will not be placed at locations with strong tension. So it helps avoid the problem?
pls see below: (a1 )Im not an expert on this question. My understanding is that cold bending can create some weak points but that depends on how much you bend it: a small bend no problems. If youre tying a ribbon/knot with reo then bending might be an issue. The guys on the construction site know this kinda of stuff.
(a2) Thats right lapping should not occur in places with significant tension. The engineers dont specify where exactly to lap in their drawings the guys on site will know though.
very well written article. I am searching for these types of topics to read for a long time.
Compression web:a member of a truss system which connects the bottom and top chords and which provides downward support.
About Work Planes - Help
Help - A work plane is a modeling feature that defines the location of a plane in 3-dimensional (3D) space. It is an infinite construction plane that can be placed at any orientation in space. It can be offset from an existing work plane, or it can reference 3D geometry. Using a work plane, you define the geometry, dimensions, constraints, and profiles that make up the part model. Work planes help you to place geometry that would otherwise be difficult to position parametrically. By constraining geometry to work planes, you can control their location. Work planes help you to define relationships between features and provide control when placing features.
A work plane is a modeling feature that defines the location of a plane in 3-dimensional (3D) space. It is an infinite construction plane that can be placed at any orientation in space. It can be offset from an existing work plane, or it can reference 3D geometry. Using a work plane, you define the geometry, dimensions, constraints, and profiles that make up the part model. Work planes help you to place geometry that would otherwise be difficult to position parametrically. By constraining geometry to work planes, you can control their location. Work planes help you to define relationships between features and provide control when placing features.
A work plane is displayed as a rectangular 2-dimensional (2D) object. The work plane display is only a visual representation of the infinite plane and cannot be moved or resized. However, you can control its visibility for ease of viewing the model. Offset and reference work planes are user-defined and provide the flexibility to be moved and redefined.
Note: To ensure a manageable model size, it is recommended to use a minimum number of work planes.
When you right-click on a work plane in the part browser, it is highlighted in the modeling area. You can change the view direction to match that of the selected work plane when adding geometry or dimensions by using the Set View option on the Work Plane context menu.
Attention: Any features attached to a work plane are restricted to the original plane. If you move a work plane, any features attached to the plane also move. If you delete a work plane, any features attached to the plane are also deleted. Each feature attached to a work plane appears under the Work Plane folder in the part browser.
Content Builder provides 3 default work planes that intersect at the origin of the X, Y, and Z axes. The default work planes help you to get started with modeling a part. You can add work planes at any time during the modeling process. Each work plane has its own internal coordinate system. Work planes can be created on any plane in the current user coordinate system (UCS) or in the World Coordinate System (WCS).
The following preset work planes can be added to a model from the Create Work Plane dialog box:
Default - Creates the standard ZX, YZ, and XY work planes of the WCS.
Creates the standard ZX, YZ, and XY work planes of the WCS.
Custom - Creates a work plane that is not available by the preset work planes. The work plane has user-defined values for the X and Y direction and the origin of the plane in the current UCS.
Creates a work plane that is not available by the preset work planes. The work plane has user-defined values for the X and Y direction and the origin of the plane in the current UCS.
Offset - Creates a work plane that is offset by a specified distance from a selected source work plane. For more information, see Offset and Reference Work Planes.
Creates a work plane that is offset by a specified distance from a selected source work plane. For more information, see Offset and Reference Work Planes.
Reference - Creates a work plane that is attached to the extents of a modifier feature. For more information, see Offset and Reference Work Planes.
Creates a work plane that is attached to the extents of a modifier feature. For more information, see Offset and Reference Work Planes.
Top - Creates a work plane that matches the standard Top 3D view.
Creates a work plane that matches the standard Top 3D view.
Bottom - Creates a work plane that matches the standard Bottom 3D view.
Creates a work plane that matches the standard Bottom 3D view.
Construction site and equipment prepared for start of work in Cologne, Germany (2017)
A large construction site of the Kalasatama area in Helsinki, Finland (2021)
Construction is a general term meaning the art and science to form objects, systems, or organizations,[1] and comes from Latin constructio (from com- "together" and struere "to pile up") and Old French construction.[2] To construct is the verb: the act of building, and the noun is construction: how something is built, the nature of its structure.
In its most widely used context, construction covers the processes involved in delivering buildings, infrastructure and industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design, and continues until the asset is built and ready for use; construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning.
As an industry, construction accounts for more than 10% of global GDP (6-9% in developed countries) and employs around 7% of the global workforce - over 273m people. The output of the global construction industry was worth an estimated $10.8 trillion in 2017.
The first huts and shelters were constructed by hand or with simple tools. As cities grew during the Bronze Age, a class of professional craftsmen, like bricklayers and carpenters, appeared. Occasionally, slaves were used for construction work. In the Middle Ages, the artisan craftsmen were organized into guilds. In the 19th century, steam-powered machinery appeared, and, later, diesel- and electric-powered vehicles such as cranes, excavators and bulldozers.
Fast-track construction has been increasingly popular in the 21st century. Some estimates suggest that 40% of construction projects are now fast-track construction.[3]
Broadly, there are three sectors of construction: buildings, infrastructure and industrial:[4]
Building construction is usually further divided into residential and non-residential.
Infrastructure, also called heavy civil or heavy engineering, includes large public works, dams, bridges, highways, railways, water or wastewater and utility distribution.
The industry can also be classified into sectors or markets.[5] For example, Engineering News-Record (ENR), a US-based construction trade magazine, has compiled and reported data about the size of design and construction contractors. In 2014, it split the data into nine market segments: transportation, petroleum, buildings, power, industrial, water, manufacturing, sewer/waste, telecom, hazardous waste, and a tenth category for other projects.[6] ENR used data on transportation, sewer, hazardous waste and water to rank firms as heavy contractors.[7]
Military residential unit construction by U.S. Navy personnel in Afghanistan
Building construction is the process of adding structures to areas of land, also known as real property sites. Typically, a project is instigated by or with the owner of the property (who may be an individual or an organisation); occasionally, land may be compulsorily purchased from the owner for public use.
Residential construction practices, technologies, and resources must conform to local building authority regulations and codes of practice. Materials readily available in the area generally dictate the construction materials used (eg: brick versus stone versus timber). Costs of construction on a per square meter (or per square foot) basis for houses can vary dramatically based on site conditions, access routes, local regulations, economies of scale (custom-designed homes are often more expensive to build) and the availability of skilled tradespeople.
Depending upon the type of building, non-residential building construction can be procured by a wide range of private and public organisations, including local authorities, educational and religious bodies, transport undertakings, retailers, hoteliers, property developers, financial institutions and other private companies. Most construction in these sectors is undertaken by general contractors.
Civil engineering covers the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, tunnels, airports, water and sewerage systems, pipelines, and railways.[10][11] Some general contractors have expertise in civil engineering; civil engineering contractors are firms dedicated to work in this sector, and may specialise in particular types of infrastructure.
Some construction projects are small renovations or repair jobs, where the owner may act as designer, paymaster and laborer for the entire project. However, more complex or ambitious projects usually require additional multi-disciplinary expertise and manpower, so the owner may commission one or more specialist businesses to undertake detailed planning, design, construction and handover of the work. Often the owner will appoint one business to oversee the project (this may be a designer, a contractor, a construction manager, or other advisor); such specialists are normally appointed for their expertise in project delivery, and will help the owner define the project brief, agree a budget and schedule, liaise with relevant public authorities, and procure the services of other specialists (the supply chain, comprising subcontractors). Contracts are agreed for the delivery of services by all businesses, alongside other detailed plans aimed at ensuring legal, timely, on-budget and safe delivery of the specified works.
Design, finance, and legal aspects overlap and interrelate. The design must be not only structurally sound and appropriate for the use and location, but must also be financially possible to build, and legal to use. The financial structure must be adequate to build the design provided, and must pay amounts that are legally owed. Legal structures integrate design with other activities, and enforce financial and other construction processes.
These processes also affect procurement strategies. Clients may, for example, appoint a business to design the project after which a competitive process is undertaken to appoint a lead contractor to construct the asset (designbidbuild); they may appoint a business to lead both design and construction (design-build); or they may directly appoint a designer, contractor and specialist subcontractors (construction management).[12] Some forms of procurement emphasise collaborative relationships (partnering, alliancing) between the client, the contractor, and other stakeholders within a construction project, seeking to ameliorate often highly competitive and adversarial industry practices.
Digging the foundation for a building construction in Jakarta, Indonesia
When applicable, a proposed construction project must comply with local land-use planning policies including zoning and building code requirements. A project will normally be assessed (by the 'authority having jurisdiction', AHJ, typically the municipality where the project will be located) for its potential impacts on neighbouring properties, and upon existing infrastructure (transportation, social infrastructure, and utilities including water supply, sewerage, electricity, telecommunications, etc). Data may be gathered through site analysis, site surveys and geotechnical investigations. Construction normally cannot start until planning permission has been granted, and may require preparatory work to ensure relevant infrastructure has been upgraded before building work can commence. Preparatory works will also include surveys of existing utility lines to avoid damage-causing outages and other hazardous situations.
Some legal requirements come from malum in se considerations, or the desire to prevent indisputably bad phenomena, e.g. explosions or bridge collapses. Other legal requirements come from malum prohibitum considerations, or factors that are a matter of custom or expectation, such as isolating businesses from a business district or residences from a residential district. An attorney may seek changes or exemptions in the law that governs the land where the building will be built, either by arguing that a rule is inapplicable (the bridge design will not cause a collapse), or that the custom is no longer needed (acceptance of live-work spaces has grown in the community).[13]
During the construction of a building, a municipal building inspector usually inspects the ongoing work periodically to ensure that construction adheres to the approved plans and the local building code. Once construction is complete, any later changes made to a building or other asset that affect safety, including its use, expansion, structural integrity, and fire protection, usually require municipality approval.
Depending on the type of project, mortgage bankers, accountants, and cost engineers may participe in creating an overall plan for the financial management of a construction project. The presence of the mortgage banker is highly likely, even in relatively small projects since the owner's equity in the property is the most obvious source of funding for a building project. Accountants act to study the expected monetary flow over the life of the project and to monitor the payouts throughout the process. Professionals including cost engineers, estimators and quantity surveyors apply expertise to relate the work and materials involved to a proper valuation.
Financial planning ensures adequate safeguards and contingency plans are in place before the project is started, and ensures that the plan is properly executed over the life of the project. Construction projects can suffer from preventable financial problems. Underbids happen when builders ask for too little money to complete the project. Cash flow problems exist when the present amount of funding cannot cover the current costs for labour and materials; such problems may arise even when the overall budget is adequate, presenting a temporary issue. Cost overruns with government projects have occurred when the contractor identified change orders or project changes that increased costs, which are not subject to competition from other firms as they have already been eliminated from consideration after the initial bid.[14] Fraud is also an occasional construction issue.[15]
Large projects can involve highly complex financial plans and often start with a conceptual estimate performed by a building estimator. As portions of a project are completed, they may be sold, supplanting one lender or owner for another, while the logistical requirements of having the right trades and materials available for each stage of the building construction project carries forward. Publicprivate partnerships (PPPs) or private finance initiatives (PFIs) may also be used to help delivery major projects. According to McKinsey in 2019, the "vast majority of large construction projects go over budget and take 20% longer than expected".[16]
Construction along Ontario Highway 401, widening the road from six to twelve travel lanes
A construction project is a complex net of construction contracts and other legal obligations, each of which all parties must carefully consider. A contract is the exchange of a set of obligations between two or more parties, and provides structures to manage issues. For example, construction delays can be costly, so construction contracts set out clear expectations and clear paths to manage delays. Poorly drafted contracts can lead to confusion and costly disputes.
At the start of a project, legal advisors seek to identify ambiguities and other potential sources of trouble in the contract structures, and to present options for preventing problems. During projects, they work to avoid and resolve conflicts that arise. In each case, the lawyer facilitates an exchange of obligations that matches the reality of the project.
Design-bid-build is the most common and well-established method of construction procurement. In this arrangement, the architect, engineer or builder acts for the client as the project coordinator. They design the works, prepare specifications and design deliverables (models, drawings, etc), administer the contract, tender the works, and manage the works from inception to completion. In parallel, there are direct contractual links between the client and the main contractor, who, in turn, has direct contractual relationships with subcontractors. The arrangement continues until the project is ready for handover.
Design-build became more common from the late 20th century, and involves the client contracting a single entity to provide design and construction. In some cases, the design-build package can also include finding the site, arranging funding and applying for all necessary statutory consents. Typically, the client invites several D&B contractors to submit proposals to meet the project brief and then selects a preferred supplier. Often this will be a consortium involving a design firm and a contractor (sometimes more than one of each). In the United States, departments of transportation usually use design-build contracts as a way of progressing projects where states lack the skills or resources, particularly for very large projects.[17]
In a construction management arrangement, the client enters into separate contracts with the designer (architect or engineer), a construction manager, and individual trade contractors. The client takes on the contractual role, while the construction or project manager provides the active role of managing the separate trade contracts, and ensuring that they complete all work smoothly and effectively together. This approach is often used to speed up procurement processes, to allow the client greater flexibility in design variation throughout the contract, to enable the appointment of individual work contractors, to separate contractual responsibility on each individual throughout the contract, and to provide greater client control.
In the industrialized world, construction usually involves the translation of designs into reality. Most commonly (ie: in a design-bid-build project), the design team is employed by (i.e. in contract with) the property owner. Depending upon the type of project, a design team may include architects, civil engineers, mechanical engineers, electrical engineers, structural engineers, fire protection engineers, planning consultants, architectural consultants, and archaeological consultants. A 'lead designer' will normally be identified to help coordinate different disciplinary inputs to the overall design. This may be aided by integration of previously separate disciplines (often undertaken by separate firms) into multi-disciplinary firms with experts from all related fields,[18] or by firms establishing relationships to support design-build processes.
The increasing complexity of construction projects creates the need for design professionals trained in all phases of a project's life-cycle and develop an appreciation of the asset as an advanced technological system requiring close integration of many sub-systems and their individual components, including sustainability. For buildings, building engineering is an emerging discipline that attempts to meet this new challenge.
Traditionally, design has involved the production of sketches, architectural and engineering drawings, and specifications. Until the late 20th century, drawings were largely hand-drafted; adoption of computer-aided design (CAD) technologies then improved design productivity, while the 21st-century introduction of building information modeling (BIM) processes has involved the use of computer-generated models that can be used in their own right or to generate drawings and other visualisations as well as capturing non-geometric data about building components and systems.
On some projects, work on-site will not start until design work is largely complete; on others, some design work may be undertaken concurrently with the early stages of on-site activity (for example, work on a building's foundations may commence while designers are still working on the detailed designs of the building's internal spaces). Some projects may include elements that are designed for off-site construction (see also prefabrication and modular building) and are then delivered to the site ready for erection, installation or assembly.
Once contractors and other relevant professionals have been appointed and designs are sufficiently advanced, work may commence on the project site. Typically, a construction site will include a secure perimeter to restrict unauthorised access, site access control points, office and welfare accommodation for personnel from the main contractor and other firms involved in the project team, and storage areas for materials, machinery and equipment. According to the McGraw-Hill Dictionary of Architecture and Construction's definition, construction may be said to have started when the first feature of the permanent structure has been put in place, such as pile driving, or the pouring of slabs or footings.[19]
Commissioning is the process of verifying that all subsystems of a new building (or other asset) work as intended to achieve the owner's project requirements and as designed by the project's architects and engineers.
Maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, governmental, and residential installations.[20][21]
Demolition is the discipline of safely and efficiently tearing down buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for reuse purposes (recycling - see also circular economy).
Helicopter view of the Atacama Large Millimeter/submillimeter Array (ALMA) Operations Support Facility (OSF) construction site
The output of the global construction industry was worth an estimated $10.8 trillion in 2017, and in 2018 was forecast to rise to $12.9 trillion by 2022.[22] As a sector, construction accounts for more than 10% of global GDP (in developed countries, construction comprises 6-9% of GDP),[23] and employs around 7% of the total employed workforce around the globe[24] (accounting for over 273 million full- and part-time jobs in 2014).[25] Since 2010,[26] China has been the world's largest single construction market.[27] The United States is the second largest construction market with a 2018 output of $1.581 trillion.[28]
In the United States in February 2020, around $1.4 trillion worth of construction work was in progress, according to the Census Bureau, of which just over $1.0 trillion was for the private sector (split roughly 55:45% between residential and nonresidential); the remainder was public sector, predominantly for state and local government.[29]
Construction is a major source of employment in most countries; high reliance on small businesses, and under-representation of women are common traits. For example:
In the US, construction employed around 11.4m people in 2020, with a further 1.8m employed in architectural, engineering, and related professional services - equivalent to just over 8% of the total US workforce.[30] The construction workers were employed in over 843,000 organisations, of which 838,000 were privately held businesses.[31] In March 2016, 60.4% of construction workers were employed by businesses with fewer than 50 staff.[32] Women are substantially underrepresented (relative to their share of total employment), comprising 10.3% of the US construction workforce, and 25.9% of professional services workers, in 2019.[30]
In the United Kingdom, construction contributed 117 billion (6%) to UK GDP in 2018, and in 2019 employed 2.4m workers (6.6% of all jobs). These worked either for 343,000 'registered' construction businesses, or for 'unregistered' businesses, typically self-employed contractors;[33] just over one million small/medium-sized businesses, mainly self-employed individuals, worked in the sector in 2019, comprising about 18% of all UK businesses.[34] Women comprised 12.5% of the UK construction workforce.[35]
In Armenia, the construction sector experienced growth during the latter part of 2000s. Based on National Statistical Service, Armenias construction sector generated approximately 20% of Armenias GDP during the first and second quarters of 2007. In 2009, according to the World Bank, 30% of Armenias economy was from construction sector.[36]
According to McKinsey research, productivity growth per worker in construction has lagged behind many other industries across different countries including in the United States and in European countries. In the United States, construction productivity per worker has declined by half since the 1960s.[37]
A truck operator at Al Gamil, the largest construction company in Djibouti
There are many routes to the different careers within the construction industry. There are three main tiers based on educational background and training, which vary by country:
Unskilled and semi-skilled workers provide general site labor, often have few or no construction qualifications, and may receive basic site training.
Professional, technical or managerial personnel[edit]
Professional, technical and managerial personnel often have higher education qualifications, usually graduate degrees, and are trained to design and manage construction processes. These roles require more training as they demand greater technical knowledge, and involve more legal responsibility. Example roles (and qualification routes) include:
Architect Will usually have studied architecture to degree level, and then undertaken further study and gained professional experience. In many countries, the title of "architect" is protected by law, strictly limiting its use to qualified people.
Civil engineer Typically holds a degree in a related subject and may only be eligible for membership of a professional institution (such as the UK's ICE) following completion of additional training and experience. In some jurisdictions, a new university graduate must hold a master's degree to become chartered,[a] and persons with bachelor's degrees may become Incorporated Engineers.
Building services engineer May also be referred to as an "M&E" or "MEP engineer" and typically holds a degree in mechanical or electrical engineering.[a]
Project manager Typically holds a 4-year or greater higher education qualification, but are often also qualified in another field such as architecture, civil engineering or quantity surveying.
Structural engineer Typically holds a bachelor's or master's degree in structural engineering.[a]
At-risk workers without appropriate safety equipment - Construction is one of the most dangerous occupations in the world, incurring more occupational fatalities than any other sector in both the United States and in the European Union.[40][41] In the US in 2019, 1,061, or about 20%, of worker fatalities in private industry occurred in construction.[40] In 2017, more than a third of US construction fatalities (366 out of 971 total fatalities) were the result of falls.[42] Proper safety equipment such as harnesses, hard hats and guardrails and procedures such as securing ladders and inspecting scaffolding can curtail the risk of occupational injuries in the construction industry.[43] Other major causes of fatalities in the construction industry include electrocution, transportation accidents, and trench cave-ins.[44]
Construction is one of the most dangerous occupations in the world, incurring more occupational fatalities than any other sector in both the United States and in the European Union.[40][41] In the US in 2019, 1,061, or about 20%, of worker fatalities in private industry occurred in construction.[40] In 2017, more than a third of US construction fatalities (366 out of 971 total fatalities) were the result of falls.[42] Proper safety equipment such as harnesses, hard hats and guardrails and procedures such as securing ladders and inspecting scaffolding can curtail the risk of occupational injuries in the construction industry.[43] Other major causes of fatalities in the construction industry include electrocution, transportation accidents, and trench cave-ins.[44]
Roofing requires appropriate personal protective equipment. - Other safety risks for workers in construction include hearing loss due to high noise exposure, musculoskeletal injury, chemical exposure, and high levels of stress.[45] Besides that, the high turnover of workers in construction industry imposes a huge challenge of accomplishing the restructuring of work practices in individual workplaces or with individual workers.[citation needed] Construction has been identified by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector in the National Occupational Research Agenda (NORA) to identify and provide intervention strategies regarding occupational health and safety issues.[46][47]
Other safety risks for workers in construction include hearing loss due to high noise exposure, musculoskeletal injury, chemical exposure, and high levels of stress.[45] Besides that, the high turnover of workers in construction industry imposes a huge challenge of accomplishing the restructuring of work practices in individual workplaces or with individual workers.[citation needed] Construction has been identified by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector in the National Occupational Research Agenda (NORA) to identify and provide intervention strategies regarding occupational health and safety issues.[46][47]
Sustainability is an aspect of green building", defined by the United States Environmental Protection Agency (EPA) as "the practice of creating structures and using processes that are environmentally responsible and resource-efficient throughout a building's life-cycle from siting to design, construction, operation, maintenance, renovation and deconstruction."[48]
^ "Construction" def. 1.a. 1.b. and 1.c. Oxford English Dictionary Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009
^ Alsever, Jennifer (December 2019). "Bots Start Building". Fortune (Paper). New York, New York: Fortune Media (USA) Corporation. p. 36. ISSN 0015-8259.
^ McGraw-Hill Dictionary of Architecture and Construction, "Start of construction", accessed 8 September 2020
^ "European Federation of National Maintenance Societies". EFNMS.org. Retrieved 5 August 2016. All actions which have the objective of retaining or restoring an item in or to a state in which it can perform its required function. These include the combination of all technical and corresponding administrative, managerial, and supervision actions.
^ Rhodes, Chris (16 December 2019). Briefing Paper: Construction industry: statistics and policy. London: House of Commons Library.
^ Rhodes, Chris (16 December 2019). Briefing Paper: Business statistics. London: House of Commons Library.
^ Swanson, Naomi; Tisdale-Pardi, Julie; MacDonald, Leslie; Tiesman, Hope M. (13 May 2013). "Women's Health at Work". National Institute for Occupational Safety and Health. Retrieved 21 January 2015.
^ a b c In the UK, the Chartered Engineer qualification is controlled by the Engineering Council, and is often achieved through membership of the relevant professional institution (ICE, CIBSE, IStructE, etc).
Wikimedia Commons has media related to Construction. - create
create - Definition of create
Definition of create - 1 : to bring into existence God created the heaven and the earth. Genesis 1:1 (King James Version)
1 : to bring into existence God created the heaven and the earth. Genesis 1:1 (King James Version)
2a : to invest with a new form, office, or rank She was created a lieutenant.
b : to produce or bring about by a course of action or behavior Her arrival created a terrible fuss. create new jobs
3 : cause, occasion Famine creates high food prices.
4a : to produce through imaginative skill create a painting
1 : to make or bring into existence something new an artist who is good at imitating but not at creating
2 : to set up a scoring opportunity in basketball create off the dribble
Examples of create in a Sentence - Verb Several new government programs were created while she was governor. The President has announced a plan to create new jobs. the scientists who created the world's first atomic bomb The machine creates a lot of noise. It can be hard to create a balance between work and family. She creates a friendly and welcoming atmosphere for her guests. The advertisements are intended to create demand for the product. I've been creating music for over 30 years. She enjoys creating new dishes by combining unusual ingredients.
Verb Several new government programs were created while she was governor. The President has announced a plan to create new jobs. the scientists who created the world's first atomic bomb The machine creates a lot of noise. It can be hard to create a balance between work and family. She creates a friendly and welcoming atmosphere for her guests. The advertisements are intended to create demand for the product. I've been creating music for over 30 years. She enjoys creating new dishes by combining unusual ingredients.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'create.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
See More - First Known Use of create
First Known Use of create - History and Etymology for create
History and Etymology for create - Verb
Verb - Middle English createn, borrowed from Latin cretus, past participle of crere "to bring into being, beget, give birth to, cause to grow," causative derivative from the base of crscere "to come into existence, increase in size or numbers, grow" more at crescent entry 1
Middle English createn, borrowed from Latin cretus, past participle of crere "to bring into being, beget, give birth to, cause to grow," causative derivative from the base of crscere "to come into existence, increase in size or numbers, grow" more at crescent entry 1
Adjective - Middle English creat, borrowed from Latin cretus, past participle of crere "to bring into being, beget, give birth to, cause to grow" more at create entry 1
Middle English creat, borrowed from Latin cretus, past participle of crere "to bring into being, beget, give birth to, cause to grow" more at create entry 1
English Language Learners Definition of create - : to make or produce (something) : to cause (something new) to exist
: to make or produce (something) : to cause (something new) to exist
: to cause (a particular situation) to exist
: to produce (something new, such as a work of art) by using your talents and imagination
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date - Definition of date
Definition of date - (Entry 1 of 3)
(Entry 1 of 3) - 1 : the brown, oblong edible fruit of a palm (Phoenix dactylifera) cookies with raisins and chopped dates
1 : the brown, oblong edible fruit of a palm (Phoenix dactylifera) cookies with raisins and chopped dates
2 : the tall palm with pinnate leaves that yields the date
1a : the time at which an event occurs the date of his birth on this date in history
b : a statement of the time of execution (see execution sense 1) or making the date on the letter
2 : duration the short date of all things sweet Rebecca P. Parkin
3 : the period of time to which something belongs a style from a later date
4a : an appointment to meet at a specified time set up a date with her lawyer especially : a social engagement (see engagement sense 1a) between two persons that often has a romantic character asked her out on a date
b : a person with whom one has a usually romantic date bringing a date to the dance
5 : an engagement for a professional performance (as of a dance band) concert dates
1 : to determine the period of time to which something belongs : to determine the date (see date entry 2 sense 3) of date an antique dated the fossils to the Triassic period
2 : to record the time of the execution or making of : mark with the date forgot to date the check a letter dated the fifth of September
3a : to mark with characteristics typical of a particular period
b : to show up plainly the age of old-fashioned decor that really dates the house
4 : to make a usually romantic social arrangement to meet with : to have a date with someone she dated in high school
1 : to estimate or compute a date (see date entry 2 sense 3) or chronology : to reckon chronologically scientific dating techniques
2 : originate a friendship dating from college days jewelry dating back to the 1700s
4 : to go out on usually romantic dates wasn't allowed to date until she was sixteen
Synonyms for date - Did You Know?
Did You Know? - The word date that means the fruit of the palm and the word date that means the time of an event look alike, but they are not related. The word for the fruit can be traced back to the Greek word daktylos, meaning finger and toe. No one knows why the fruit was called by the word for fingerperhaps because of its small size and shape or the long, slender shape of the palms leaves. The word for the time of an event comes from Latin and derives from the Latin phrase data Romae, meaning given at Rome, an expression used before the date on letters and documents. The word data comes from the Latin word dare, to give. In later Latin, the word data came to be used alone to stand for the date, and it came into English as date.
The word date that means the fruit of the palm and the word date that means the time of an event look alike, but they are not related. The word for the fruit can be traced back to the Greek word daktylos, meaning finger and toe. No one knows why the fruit was called by the word for fingerperhaps because of its small size and shape or the long, slender shape of the palms leaves. The word for the time of an event comes from Latin and derives from the Latin phrase data Romae, meaning given at Rome, an expression used before the date on letters and documents. The word data comes from the Latin word dare, to give. In later Latin, the word data came to be used alone to stand for the date, and it came into English as date.
Examples of date in a Sentence - Verb She dated a couple guys during college. He only dates younger women. They've been dating for six months. Don't forget to sign and date the application. The letter was not dated. a memo dated July 12th, 2003 Historians date the document to the early 1700s. The ancient building was dated by a coin found in one of the rooms. Scientists use various techniques to date fossils.
Verb She dated a couple guys during college. He only dates younger women. They've been dating for six months. Don't forget to sign and date the application. The letter was not dated. a memo dated July 12th, 2003 Historians date the document to the early 1700s. The ancient building was dated by a coin found in one of the rooms. Scientists use various techniques to date fossils.
First Known Use of date - History and Etymology for date
History and Etymology for date - Noun (1)
Noun (1) - Middle English, from Anglo-French, ultimately from Latin dactylus more at dactyl
Middle English, from Anglo-French, ultimately from Latin dactylus more at dactyl
Noun (2) and Verb - Middle English, from Anglo-French, from Late Latin data, from data (as in data Romae given at Rome), feminine of Latin datus, past participle of dare to give; akin to Latin dos gift, dowry, Greek didonai to give
Middle English, from Anglo-French, from Late Latin data, from data (as in data Romae given at Rome), feminine of Latin datus, past participle of dare to give; akin to Latin dos gift, dowry, Greek didonai to give
Kids Definition of date - 1 : the day, month, or year on which an event happens or happened What is your date of birth?
1 : the day, month, or year on which an event happens or happened What is your date of birth?
2 : a statement of time on something (as a coin, letter, book, or building) Write the date on your paper.
3 : appointment sense 1 Louis paid no attention to the other birds. He had a date to keep. E. B. White, The Trumpet of the Swan
4 : an arrangement to meet between two people usually with romantic feelings for each other It's not a datewe're just friends.
5 : either of two people who meet for a usually romantic social engagement Do you have a date for the dance?
1 : to write the date on Be sure to date the letter.
2 : to find or show the date or age of Scientists dated the fossil.
3 : to belong to or have survived from a time My house dates from colonial times.
4 : to make or have a date with I'm dating him tonight.
5 : to go together regularly on romantic social engagements They've been dating for a year.
What made you want to look up date? Please tell us where you read or heard it (including the quote, if possible).
Choose the best definition or synonym for the word in bold: "There are some eructations that sound like cheersat least, mine did." Lolita
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Description - Look up description in Wiktionary, the free dictionary.
Look up description in Wiktionary, the free dictionary.
Description is the pattern of narrative development that aims to make vivid a place, object, character, or group.[1] Description is one of four rhetorical modes (also known as modes of discourse), along with exposition, argumentation, and narration.[2] In practice it would be difficult to write literature that drew on just one of the four basic modes.[3]
Contents - Fiction-writing also has modes: action, exposition, description, dialogue, summary, and transition.[4] Author Peter Selgin refers to methods, including action, dialogue, thoughts, summary, scenes, and description.[5] Currently, there is no consensus within the writing community regarding the number and composition of fiction-writing modes and their uses.
Fiction-writing also has modes: action, exposition, description, dialogue, summary, and transition.[4] Author Peter Selgin refers to methods, including action, dialogue, thoughts, summary, scenes, and description.[5] Currently, there is no consensus within the writing community regarding the number and composition of fiction-writing modes and their uses.
Description is the fiction-writing mode for transmitting a mental image of the particulars of a story. Together with dialogue, narration, exposition, and summarization, description is one of the most widely recognized of the fiction-writing modes. As stated in Writing from A to Z, edited by Kirk Polking, description is more than the amassing of details; it is bringing something to life by carefully choosing and arranging words and phrases to produce the desired effect.[6] The most appropriate and effective techniques for presenting description are a matter of ongoing discussion among writers and writing coaches.
A purple patch is an over-written passage in which the writer has strained too hard to achieve an impressive effect, by elaborate figures or other means. The phrase (Latin: "purpureus pannus") was first used by the Roman poet Horace in his Ars Poetica (c. 20 BC) to denote an irrelevant and excessively ornate passage; the sense of irrelevance is normally absent in modern usage, although such passages are usually incongruous. By extension, purple prose is lavishly figurative, rhythmic, or otherwise overwrought.[7]
Morrell, Jessica Page (2006). Between the Lines: Master the Subtle Elements of Fiction Writing. Cincinnati, OH: Writer's Digest Books. p. 127. ISBN 978-1-58297-393-7.
Rozakis, Laurie (2003). The Complete Idiot's Guide to Grammar and Style, 2nd Edition. Alpha. ISBN 978-1-59257-115-4
Slope - The incline angle of a roof surface, given as a ratio of the rise (in inches) to the run (in feet). See also pitch.
Panel - a thin flat piece of wood, plywood, or similar material, framed by stiles and rails as in a door (or cabinet door), or fitted into grooves of thicker material with molded edges for decorative wall treatment.
- The outside fan unit of the Air Conditioning system. It removes the heat from the freon gas and "turns" the gas back into a liquid and pumps the liquid back to the coil in the furnace.
- A regulatory organization which governs the design and specifications of highway bridges.
- Also referred to as the wear rating, it is the European Standard AC Rating. The range runs from the least resistant rating of AC1 To AC5, the most resistant to abrasion.
A motif derived from the large leaf of the low-growing acanthus plant. Used at an early date by the Greeks for architectural scrolls on the capitals of the Corinthian column.
The wall in a room which has been given special design emphasis to attract attention from the adjacent walls.
Removable metal or concrete floor panels about 18" to 24" square which are supported on short steel pedestals so that wiring and ductwork may be installed, changed and maintained below the floor. The raised floor may be carpeted or tiled to create a finished floor surface.
A small metal or wood door flush with a wall or ceiling surface which provides a closure over a valve or other operable device which is recessed into the wall or located above a ceiling. The access door may be keyed and lockable.
Signifies access that requires the removal of an access panel or similar removable obstruction.
Signifies access without the necessity for removing a panel or similar obstruction.
Are extra items that can be furnished in addition to the base joist or joist girder. They include: headers, top chord extensions, extended ends, ceiling extensions, bottom chord extensions, sloped end bearings, bridging, bridging anchors, joist girder bottom chord bracing, or angle units (joist substitutes).
A building product which supplements a basic solid panel building such as a door, window, light transmitting panel, roof vent, etc.
In one- and two-family dwellings not more than three stories high with separate means of egress, a building, the use of which is incidental to that of the main building and which is located on the same lot.
A ceiling or wall tile finishing material with an inherent property to absorb sound; usually made of mineral, fiber or insulated metal materials. Not "Acoustic Tile" or "Acoustical Board."
The door people use every time they enter or leave the house. When there are double doors, it is the door that opens with an entry set knob or lever. The other door is called the inactive door and opens when the flush bolts are released.
Written or graphic instruments issued prior to the execution of the Contract which modify or interpret the bidding documents, including Drawings and Specifications, by additions, deletions, clarifications or corrections. Addenda will become part of the Contract Documents when the Construction Contract is executed. (Plural-"Addenda".)
A sticky substance to bond one material to another. Use the term "Adhere" instead of "Glue." Do not use "Glue," "Cement," or Mastic."
The person or corporate body responsible for gathering together and maintaining a group of documents.
A chemical which is added to concrete to accelerate or retard the setting process or to create air bubbles in the concrete, called "accelerators," or :air entraining agents."
Published public notice soliciting bids for a construction project. Most frequently used to conform to legal requirements pertaining to projects to be constructed under public authority, and usually published on newspapers of general circulation in those districts from which the public funds are derived.
- The round screened screw-on tip of a sink spout. It mixes water and air for a smooth flow.
A non-profit association representing the post-fabrication hot-dip galvanizing industry.
Is a national trade organization of qualified construction contractors and and industry related companies dedicated to skill, integrity, an responsibility. The AGCA is the voice of the construction industry and is dedicated to improving the quality of construction and protecting the public.
(1) A legally enforceable promise or promises between two or among several persons. (2) On a construction project, the document stating the essential terms of the Construction Contract which incorporates by reference the other Contract Documents. (3) The document setting forth the terms of the Contract between the Architect and a consultant.
A structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other agricultural products. Such structure shall not include habitable or occupiable spaces, spaces in which agricultural products are processed, treated or packaged; nor shall an agricultural building be a place of occupancy by the general public.
An organization to unite in fellowship the members of the architectural profession in the United States.
A one-way valve designed to allow air into the plumbing drainage system when a negative pressure develops in the piping. This device shall close by gravity and seal the terminal under conditions of zero differential pressure (no flow conditions) and under positive internal pressure.
An arrangement in which a discharge pipe from a fixture, appliance or device drains indirectly into a receptor below the flood-level rim of the receptor, and above the trap seal.
refers to the duct that is used to carry either supply air or return air to and from the air handler. This can be fiberglass duct board, insulated metal duct, or large flex duct.
A means of providing space conditioning utilizing movement of air through ducts or plenums by mechanical means.
The process of treating air for simultaneous control of temperature, humidity, cleanliness, and distribution.
Lumber that was dried, usually outside, to an equilibrium moisture content with the air it was exposed to. Any lumber below 30% MC is classified as air dried. Construction grade is around 19% MC and in southern Ontario the relative humidity is usually between 50 to 60 % which lumber will equalize to moisture content to between 8 to 14% MC.
expresses the amount air that flows through an air duct per minute. The air flow is measured and is expressed in cubic feet per minute (CFM).
Amount of air that passes between a window sash and frame. In windows it is measured in terms of cubic feet or air per minute, per square foot of area. The lower the number, the less air the window lets pass through.
The area between insulation facing and interior of exterior wall coverings. Normally a 1" air gap.
The unobstructed vertical distance through free atmosphere between the outlet of a waste pipe and the flood-level rim of the fixture or receptor into which it is discharging.
The unobstructed vertical distance through free atmosphere between the lowest opening from a water supply discharge to the flood-level rim of a plumbing fixture.
Is a non-profit technical specifying and trade organization for the fabricated structural steel industry in the United States. It was founded in 1921 with headquarters located in Chicago. One of their best known manuals is the Manual of Steel Construction.
A paint composed of a chemically synthesized, alkyd derived base, thinned with mineral spirits. The current version of "oil" based paints.
The typical effect produced by a wall covering. A pattern in which the units of design are evenly distributed over a surface, without undue emphasis.
Coarse checking pattern characterized by a slipping of the new paint coating over the old coating to the extent that the old coating can be seen through the fissures.
A sum of money set aside in the construction contract for items which have not been selected and specified in the construction contract. For example, selection of tile as flooring may require an allowance for an underlayment material, or an electrical allowance which sets aside an amount of money to be spent on electrical fixtures.
Any construction or renovation to an existing structure other than repair or addition that requires a permit. Also, a change in a mechanical system that involves an extension, addition or change to the arrangement, type or purpose of the original installation that requires a permit.
Mechanism used in Bid Documents to seek separate bids for a different design than the "Base Bid" design. May be "Additive" or "Deductive" alternates.
Window with wood construction covered with aluminum sheet. Has a factory-applied finish to protect from weather and solar degradation.
A quantity of wallpaper between 34 to 36 square feet. The width of the roll is usually 20.5 inches, however, it can be up to 36 inches wide. The length ranges from 4 to 7 yards. (Compare to metric single roll)
A payment plan by which a loan is reduced through monthly payments of principal and interest.
A multiplier of the value of moment or deflection in the unbraced length of an axially loaded member to reflect secondary values generated by the eccentricity of the load.
A measure of floor vibration. It is the magnitude or total distance traveled by each oscillation of the vibration.
A plan view drawing showing the diameter, location and projection of all anchor bolts for the components of the metal building system and may show column reactions (magnitude and direction). The maximum base plate dimensions may also be shown.
The process of fastening a joist or joist girder to a masonry, concrete, or steel support by either bolting or welding.
A hot rolled shape called an Angle with symbol L which has equal legs or unequal legs.
A member used as a joist substitute which is intended for use at very short spans (10 feet or less) where open web steel joists are impractical. They are usually used for short spans in skewed bays, over corridors, or for outriggers. It can be made up of two or four angles to form channel sections or box sections. Tube and channel sections are also used. See Joist Substitute.
The layer of growth that a tree puts on in one year. The annual growth rings can be seen in the and grain of lumber.
Annual cost of credit over the life of a loan, including interest, service charges, points, loan fees, mortgage insurance, and other items.
A nonprofit organization which promotes the use of U.S. standards internationally
The highest point on a joist or joist girder where the sloped chords meet. See also Peak.
A device or apparatus that is manufactured and designed to utilize energy and for which this code provides specific requirements.
A design or ornament applied to another surface. In wallpaper, cut-outs applied to a plain, textured or figured background.
- Approval drawings may include framing drawings, elevations and sections through the building as furnished by the manufacturer for approval of the buyer. Approval by the buyer affirms that the manufacturer has correctly interpreted the overall contract requirements for the metal building system and it's accessories, and the exact location of accessories in the building.
Plans sent by the joist manufacturer to the buyer, engineer, architect, contractor or other person for approval. The plans may include a framing plan, elevations, sections, and a material list.
- The term "approved," where used in conjunction with the Architect's action on the Contractor's submittal, applications, and requests, is limited to the Architect's duties and responsibilities as stated in General and Supplementary Conditions.
An established and recognized agency regularly engaged in conducting tests or furnishing inspection services, when such agency has been approved by the building official.
An in dependent per son, firm or corporation, approved by the building official, who is competent and experienced in the application of engineering principles to materials, methods or systems analyses.
Row of arches, free-standing and supported on piers or columns; a blind arcade is a "dummy".
Can be round-headed, pointed, two-centered, or drop; ogee - pointed with double curved sides, upper arcs lower concave; lancet - pointed formed on an acute-angle triangle; depressed - flattened or elliptical; corbelled - triangular, peaked, each stone set a little further in until they meet, with a large capstone.
A non-standard type of joist where both the top chord and bottom chord are curved parallel with each other.
A person who designs buildings or other structures and has completed schooling in building design or similar subjects and is licensed by the state as an architect.
is a type of shingle that is normally heavier in weight and has more definition or depth than the shingle itself.
Any medium that refers to or depicts architectural works, structures, parts of structures, or designs, whether built or unbuilt. Included are textual documents such as specifications and letters; graphic documents such as drawings, prints, and photographs; models; and any other visual media that concern any portion of the built or unbuilt environment. Subjects may include not only architectural works, but also related subjects such as furniture, engineering designs, naval architecture, textiles, architectural ornaments, paper architecture, studies, landscape designs, and stage designs.
A drawing which shows the plan view and/or elevations of the finished building for the purpose of showing the general appearance of the building, indicating all accessory locations.
Any subject or built work. It can be a study or a design of a structure, or the representation of a design as depicted on a drawing, model, print, or other medium.
are the most common appearance classifications. Premium appearance beams are available as custom orders.
Corrugated metal or concrete barrier walls installed around a basement window to hold back the earth
An open subsurface space adjacent to a building used to admit light or air or as a means of access to a basement.
An odorless, colorless, tasteless, nontoxic gas which is six times denser than air. It is used to insulate better and reduce heat transfer.
A door protection plate extending a sufficient distance up from the bottom of a door so that carts, gurneys, etc. will contact the plate when pushed against the door. 36" and 427 heights are typical.
A narrow vertical slit cut into a wall through which arrows could be fired from inside.
survey is performed to obtain horizontal and/or vertical dimensional data so that constructed improvements may be located and delineated
A drawing or print marked by the Contractor to show actual conditions of a project as constructed after construction.
Founded in 1852, is the oldest national professional engineering society in the United States. It is dedicated to the advancement of the individual civil engineer and the civil engineering profession through education.
valance is a V shaped piece of fabric, trimmed with tassel or beads that can be used free standing or as a top treatment over Panels or Poletops.
A structural design method whereby a structural element is designed so that the unit stresses computed under the action of working or service loads do not exceed specified allowable values. See Working Stress Design and Elastic Design.
Most native asphalt is a residue from evaporated petroleum. It is insoluble in water but soluble in gasoline and melts when heated. Used widely in building for waterproofing roof coverings of many types, exterior wall coverings, flooring tile, and the like.
This is the term used for paving for roads and driveways. Not "Asphalt" or "Bituminous" Concrete.
- A group of mutually dependent and compatible components or subassemblies of components.
Allows a buyer to assume responsibility for an existing loan instead of getting a new loan.
- An organization which has developed over 10,000 technical standards which are used by industries worldwide.
A molding, attached to one of a pair of swinging double doors, against which the other door strikes.
An opening or skylighted lobby through two or more floor levels other than an enclosed stairway, elevator, etc.
The unfinished space between the ceiling joists of the top story and the roof rafters.
An opening that is placed in the dry walled ceiling of a home providing access to the attic.
- Terms refers to insulation put in the attic. This is usually either batt insulation or blown insulation. The thickness will vary depending on the R value that is specified in the plans.
A poufed fabric shade with permanently shirred scallops that draw up from the bottom.
Authority control in the context of the Guide pertains to entities with proper names, i.e., people/corporate bodies, subjects/built works, and geographic locations. One of the major functions of authority control is to govern the form and content of proper names in order to ensure that all references to a given person or subject are collocated. An authority record may contain not only the preferred name, but all other names for the person or subject. An expanded authority record can also include contextual information, e.g., biographical or corporate histories.
The world's most popular computer-aided drafting software product for the personal computer in both DOS and windows by Autodesk, Inc. Anything that can be drawn on a drawing board can be drawn by AutoCAD.
A code term involving the permitted practice of holding a fire door in the open position providing the door closes upon detection. Generally the detection must be from the presence of visible or invisible particles of combustion. Fusible links are not usually considered acceptable because of slower response time. Any listed closer can be used in combination with an electromagnetic holder and a photo electric or ionization type smoke detector. Labeled or listed spring hinges could be used as well as hydraulic door closers. Some special applications of swinging, sliding and rolling fire doors primarily in industrial applications are permitted to be used with fusible links, weights and pulleys. Later product introductions are more sophisticated and provide more flexibility for building operation. These are hydraulic door closers incorporating hold open mechanisms allowing the door to be held open in many degrees of opening positions. The most recent product introduction along these lines is the so-called "swing free" unit. Instead of using a hold open mechanism, the energy of the closer is negated and the door is allowed to be operated as if it were not equipped with a closer. Upon detection of visible or invisible particles of combustion, the closing mechanism engages and the closer causes the door to return to the closed and latched position. These automatic closing arrangements are fail safe in that upon power failure, the door closes. All are listed by a nationally recognized independent testing laboratory and are under an in-plant follow-up inspection service.
The power mechanism causing the opening and closing of a door upon receipt of a actuating signal.
A girder arranged parallel to the main girder for supporting the platform motor base, operators cab, control panels, etc., to reduce the torsional forces that such load would otherwise impose on the main crane girder.
All specified dynamic live loads other than the basic design loads which the building must safely withstand, such as cranes, material handling systems, machinery, elevators, vehicles, and impact loads.
A lock having a latch bolt or a dead bolt operated by a key or a thumb turn or both. This lock is often used in addition to another lock, which may or may not be key operated but which has a latch bolt operated by knobs or levers.
) - An organization established in 1984 to bridge the gap between the findings of basic welding research and the needs of the industry.
An architectural projection that provides weather protection, identity or decoration and is wholly sup ported by the building to which it is attached. An awning is comprised of a light weight, rigid skeleton structure over which a covering is attached.
Hinged at the top and swinging out at the bottom, operated by a cranking mechanism. Usually rectangular, and wider than they are long.
- A non-profit organization whose major goal is to advance the science, technology, and application of welding and related joining disciplines.
- A load whose line of action passes through the centroid of the member's cross-sectional area and is perpendicular to the plane of the section.
A structural member designed to transfer a axial tension or compression load only.
Billings for work performed or costs incurred by one party that, in accordance with the agreement, should have been performed or incurred by the party to whom billed. Owners bill back charges to general contractors, and general contractors bill back charges to subcontractors. Examples of back charges include charges for cleanup work or to repair something damaged by another subcontractor, such as a tub chip or broken window.
The replacement of excavated earth into a trench around or against a basement /crawl space foundation wall.
Frame lumber installed between the wall studs to give additional support for drywall or an interior trim related item, such as handrail brackets, cabinets, and towel bars. In this way, items are screwed and mounted into solid wood rather than weak drywall that may allow the item to break loose from the wall. Carpet backingholds the pile fabric in place.
Work the framing contractor does after the mechanical subcontractors (Heating-Plumbing-Electrical) finish their phase of work at the Rough (before insulation) stage to get the home ready for a municipal frame inspection. Generally, the framing contractor repairs anything disturbed by others and completes all framing necessary to pass a Rough Frame Inspection.
A loan that has a series of monthly payments with the remaining balance due in a large lump sum payment at the end.
Framed walls (generally over 10' tall) that run the entire vertical length from the floor sill plate to the roof. This is done to eliminate the need for a gable end truss.
- Vertical members in a railing used between a top rail and bottom rail or the stair treads. Sometimes referred to as 'pickets' or 'spindles'.
The rail, posts and vertical balusters along the edge of a stairway or elevated walkway.
A decorative board covering the projecting rafter (fly rafter) of the gable end. At the cornice, this member is a fascia board.
Molding used next to the floor on interior base board. Sometimes called a carpet strip.
A section of fiber-glass or rock-wool insulation measuring 15 or 23 inches wide by four to eight feet long and various thicknesses. Sometimes "faced" (meaning to have a paper covering on one side) or "unfaced" (without paper).
Narrow strips of wood used to cover joints or as decorative vertical members over plywood or wide boards.
Any window space projecting outward from the walls of a building, either square or polygonal in plan.
A structural member transversely supporting a load. A structural member carrying building loads (weight) from one support to another. Sometimes called a "girder".
(a) A beam placed perpendicular to joists and to which joists are nailed in framing for a chimney, stairway, or other opening. (b) A wood lintel. (c) The horizontal structural member over an opening (for example over a door or window).
A point where a bearing or structural weight is concentrated and transferred to the foundation
A formal offer by a contractor, in accordance with specifications for a project, to do all or a phase of the work at a certain price in accordance with the terms and conditions stated in the offer.
- A bond issued by a surety on behalf of a contractor that provides assurance to the recipient of the contractor's bid that, if the bid is accepted, the contractor will execute a contract and provide a performance bond. Under the bond, the surety is obligated to pay the recipient of the bid the difference between the contractor's bid and the bid of the next lowest responsible bidder if the bid is accepted and the contractor fails to execute a contract or to provide a performance bond.
Funds or a bid bond submitted with a bid as a guarantee to the recipient of the bid that the contractor, if awarded the contract, will execute the contract in accordance with the bidding requirements of the contract documents.
- A practice by which contractors, both before and after their bids are submitted, attempt to obtain prices from potential subcontractors and material suppliers that are lower than the contractors' original estimates on which their bids are based, or after a contract is awarded, seek to induce subcontractors to reduce the subcontract price included in the bid.
The procedures and conditions for the submission of bids. The requirements are included ion documents, such as the notice to bidders, advertisements for bids, instructions to bidders, invitations to bid, and sample bid forms.
Doors that are hinged in the middle for opening in a smaller area than standard swing doors. Often used for closet doors.
A receipt for a deposit to secure the right to purchase a home at an agreed term by a buyer and seller.
Fiber-glass or rock-wool insulation that comes in long rolls 15 or 23 inches wide.
To install a box or barrier within a foundation wall to prevent the concrete from entering an area. For example, foundation walls are sometimes "blocked" in order for mechanical pipes to pass through the wall, to install a crawl space door, and to depress the concrete at a garage door location.
Wood shims used between the door frame and the vertical structural wall framing members.
Short "2 by 4's" used to keep rafters from twisting, and installed at the ends and at mid-span.
Small wood pieces to brace framing members or to provide a nailing base for gypsum board or paneling.
Fiber insulation in loose form and used to insulate attics and existing walls where framing members are not exposed.
A type of copying method often used for architectural drawings. Usually used to describe the drawing of a structure which is prepared by an architect or designer for the purpose of design and planning, estimating, securing permits and actual construction.
Another phrase for Utility Notification. This is when a utility company (telephone, gas, electric, cable TV, sewer and water, etc) comes to the job site and locates and spray paints the ground and/or installs little flags to show where their service is located underground.
- A unit of measure for lumber equal to 1 inch thick by 12 inches wide by 12 inches long. Examples: 1" x 12" x 16' = 16 board feet, 2" x 12" x 16' = 32 board feet
- An amount of money (usually $5,000-$10,000) which must be on deposit with a governmental agency in order to secure a contractor's license. The bond may be used to pay for the unpaid bills or disputed work of the contractor. Not to be confused with a 'performance bond'. Such bonds are rarely used in residential construction, they are an insurance policy which guarantees proper completion of a project.
don't - verb
verb - contraction of do not.
contraction of do not. - Nonstandard except in some dialects. contraction of does not.
Nonstandard except in some dialects. contraction of does not.
noun - don'ts, customs, rules, or regulations that forbid something: The boss has a long list of don'ts that you had better observe if you want a promotion.Compare do1 (def. 55).
don'ts, customs, rules, or regulations that forbid something: The boss has a long list of don'ts that you had better observe if you want a promotion.Compare do1 (def. 55).
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - historical usage of don't
historical usage of don't - Don't is the standard contraction for do not. As a contraction for does not, don't first appeared in writing in the latter half of the 17th century, about the same time as the first written appearance of other contracted forms with not, like mayn't and can't. Don't remained the standard contraction for does not in both speech and writing through the 18th century. During the 19th century, under pressure from those who thought it illogical and who preferred doesn't in that use, don't for does not gradually became less frequent in writing but continued to be common in speech. Don't for does not still occurs in the informal speech and in the personal writing of many Americans, including the well educated, especially in the Midland and Southern dialects. It does not occur in edited writing or formal speech.
Don't is the standard contraction for do not. As a contraction for does not, don't first appeared in writing in the latter half of the 17th century, about the same time as the first written appearance of other contracted forms with not, like mayn't and can't. Don't remained the standard contraction for does not in both speech and writing through the 18th century. During the 19th century, under pressure from those who thought it illogical and who preferred doesn't in that use, don't for does not gradually became less frequent in writing but continued to be common in speech. Don't for does not still occurs in the informal speech and in the personal writing of many Americans, including the well educated, especially in the Midland and Southern dialects. It does not occur in edited writing or formal speech.
Example sentences from the Web for don't - We brought in Don Lemon, the year that he wrote his book, and I told that story to the audience that was there.
We brought in Don Lemon, the year that he wrote his book, and I told that story to the audience that was there.
There was a handy distraction in the Che t-shirt the tourist was wearing while celebrating the death.
He was standing on the corner and wearing only a T-shirt and jeans, and this was 11:30 at night and it was really cold.
There'll be heaps uh fun in the Cypress Hills country when they get t' runnin' the whisky-jacks out.
An with that I laid down on the settee, an felt orful bad, an the more I tho't about it, the wus I felt.
I've tried to teach lots of folks; an' sum learns quick, an' some don't never learn; it's jest 's 't strikes 'em.
But ef Jos keeps on, airnin' ez much ez he hez so fur, he's goin' ter pay the Injun part on 't, when he cums.
A door is a hinged or otherwise movable barrier that allows ingress into and egress from an enclosure. The created opening in the wall is a doorway or portal. A door's essential and primary purpose is to provide security by controlling access to the doorway (portal). Conventionally, it is a panel that fits into the portal of a building, room, or vehicle. Doors are generally made of a material suited to the door's task. Doors are commonly attached by hinges, but can move by other means, such as slides or counterbalancing.
The door may be moved in various ways (at angles away from the portal, by sliding on a plane parallel to the frame, by folding in angles on a parallel plane, or by spinning along an axis at the center of the frame) to allow or prevent ingress or egress. In most cases, a door's interior matches its exterior side. But in other cases (e.g., a vehicle door) the two sides are radically different.
Doors may incorporate locking mechanisms to ensure that only some people can open them. Doors may have devices such as knockers or doorbells by which people outside announce their presence. Apart from providing access into and out of a space, doors may have the secondary functions of ensuring privacy by preventing unwanted attention from outsiders, of separating areas with different functions, of allowing light to pass into and out of a space, of controlling ventilation or air drafts so that interiors may be more effectively heated or cooled, of dampening noise, and of blocking the spread of fire.
The earliest recorded doors appear in the paintings of Egyptian tombs, which show them as single or double doors, each of a single piece of wood. People may have believed these were doors to the afterlife, and some include designs of the afterlife. In Egypt, where the climate is intensely dry, doors weren't framed against warping, but in other countries required framed doorswhich, according to Vitruvius (iv. 6.) was done with stiles (sea/si) and rails (see: Frame and panel), the enclosed panels filled with tympana set in grooves in the stiles and rails. The stiles were the vertical boards, one of which, tenoned or hinged, is known as the hanging stile, the other as the middle or meeting stile. The horizontal cross pieces are the top rail, bottom rail, and middle or intermediate rails.
The most ancient doors were made of timber, such as those referred to in the Biblical depiction of King Solomon's temple being in olive wood (I Kings vi. 31-35), which were carved and overlaid with gold. The doors that Homer mentions appear to have been cased in silver or brass. Besides olive wood, elm, cedar, oak and cypress were used. A 5,000-year-old door has been found by archaeologists in Switzerland.[2]
Ancient doors were hung by pivots at the top and bottom of the hanging stile, which worked in sockets in the lintel and sill, the latter in some hard stone such as basalt or granite. Those Hilprecht found at Nippur, dating from 2000 BC, were in dolerite. The tenons of the gates at Balawat were sheathed with bronze (now in the British Museum). These doors or gates were hung in two leaves, each about 2.54 m (100 in) wide and 8.2 m (27 ft) high; they were encased with bronze bands or strips, 25.4 cm (10.0 in) high, covered with repouss decoration of figures. The wood doors would seem to have been about 7.62 cm (3.00 in) thick, but the hanging stile was over 360 millimetres (14 in) diameter. Other sheathings of various sizes in bronze show this was a universal method adopted to protect the wood pivots. In the Hauran in Syria where timber is scarce, the doors were made of stone, and one measuring 1.63 m (5.3 ft) by 0.79 m (31 in) is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door. At Kuffeir near Bostra in Syria, Burckhardt found stone doors, 2.74 to 3.048 m (8.99 to 10.00 ft) high, being the entrance doors of the town. In Etruria many stone doors are referred to by Dennis.
Roman folding doors at Pompeii, from the 1st century AD, similar with Neoclassical doors from the 19th century
Ancient Greek and Roman doors were either single doors, double doors, triple doors, sliding doors or folding doors, in the last case the leaves were hinged and folded back. In the tomb of Theron at Agrigentum there is a single four-panel door carved in stone. In the Blundell collection is a bas-relief of a temple with double doors, each leaf with five panels. Among existing examples, the bronze doors in the church of SS. Cosmas and Damiano, in Rome, are important examples of Roman metal work of the best period; they are in two leaves, each with two panels, and are framed in bronze. Those of the Pantheon are similar in design, with narrow horizontal panels in addition, at the top, bottom and middle. Two other bronze doors of the Roman period are in the Lateran Basilica.
The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century AD during the era of Roman Egypt.[3] The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604618), who had one installed for his royal library.[3] The first automatic gate operators were later created in 1206 by Arab inventor Al-Jazari.[4][need quotation to verify]
Copper and its alloys were integral in medieval architecture. The doors of the church of the Nativity at Bethlehem (6th century) are covered with plates of bronze, cut out in patterns. Those of Hagia Sophia at Constantinople, of the 8th and 9th century, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9th century), of similar manufacture, were probably brought from Constantinople, as also some of those in St. Marks, Venice. The bronze doors on the Aachen Cathedral in Germany date back to about 800 AD. Bronze baptistery doors at the Cathedral of Florence were completed in 1423 by Ghiberti.[5] (For more information, see: Copper in architecture).
Of the 11th and 12th centuries there are numerous examples of bronze doors, the earliest being one at Hildesheim, Germany (1015). The Hildesheim design affected the concept of Gniezno door in Poland. Of others in South Italy and Sicily, the following are the finest: in Sant Andrea, Amalfi (1060); Salerno (1099); Canosa (1111); Troia, two doors (1119 and 1124); Ravello (1179), by Barisano of Trani, who also made doors for Trani cathedral; and in Monreale and Pisa cathedrals, by Bonano of Pisa. In all these cases the hanging stile had pivots at the top and bottom. The exact period when the builder moved to the hinge is unknown, but the change apparently brought about another method of strengthening and decorating doorswrought-iron bands of various designs. As a rule, three bands with ornamental work constitute the hinges, with rings outside the hanging stiles that fit on vertical tenons set into the masonry or wooden frame. There is an early example of the 12th century in Lincoln. In France, the metalwork of the doors of Notre Dame at Paris is a beautiful example, but many others exist throughout France and England.
In Italy, celebrated doors include those of the Battistero di San Giovanni (Florence), which are all in bronzeincluding the door frames. The modeling of the figures, birds and foliage of the south doorway, by Andrea Pisano (1330), and of the east doorway by Ghiberti (14251452), are of great beauty. In the north door (14021424), Ghiberti adopted the same scheme of design for the paneling and figure subjects as Andrea Pisano, but in the east door, the rectangular panels are all filled, with bas-reliefs that illustrate Scripture subjects and innumerable figures. These may the gates of Paradise of which Michelangelo speaks.
Doors of the mosques in Cairo were of two kinds: those externally cased with sheets of bronze or iron, cut in decorative patterns, and incised or inlaid, with bosses in relief; and those of wood-framed with interlaced square and diamond designs. The latter design is Coptic in origin. The doors of the palace at Palermo, which were made by Saracenic workmen for the Normans, are fine examples in good preservation. A somewhat similar decorative class of door is found in Verona, where the edges of the stiles and rails are beveled and notched.
In the Renaissance period, Italian doors are quite simple, their architects trusting more to the doorways for effect; but in France and Germany the contrary is the case, the doors being elaborately carved, especially in the Louis XIV and Louis XV periods, and sometimes with architectural features such as columns and entablatures with pediment and niches, the doorway being in plain masonry. While in Italy the tendency was to give scale by increasing the number of panels, in France the contrary seems to have been the rule; and one of the great doors at Fontainebleau, which is in two leaves, is entirely carried out as if consisting of one great panel only.
The earliest Renaissance doors in France are those of the cathedral of St. Sauveur at Aix (1503). In the lower panels there are figures 3 ft (0.91 m). high in Gothic niches, and in the upper panels a double range of niches with figures about 2 ft (0.61 m). high with canopies over them, all carved in cedar. The south door of Beauvais Cathedral is in some respects the finest in France; the upper panels are carved in high relief with figure subjects and canopies over them. The doors of the church at Gisors (1575) are carved with figures in niches subdivided by classic pilasters superimposed. In St. Maclou at Rouen are three magnificently carved doors; those by Jean Goujon have figures in niches on each side, and others in a group of great beauty in the center. The other doors, probably about forty to fifty years later, are enriched with bas-reliefs, landscapes, figures and elaborate interlaced borders.
NASA's Vehicle Assembly Building at the Kennedy Space Center contains the four largest doors. The Vehicle Assembly Building was originally built for the assembly of the Apollo missions' Saturn vehicles and was then used to support Space Shuttle operations. Each of the four doors are 139 meters (456 feet) high.[6]
The oldest door in England can be found in Westminster Abbey and dates from 1050.[7] In England in the 17th century the door panels were raised with bolection or projecting moldings, sometimes richly carved, around them; in the 18th century the moldings worked on the stiles and rails were carved with the egg-and-dart ornament.
Art Nouveau metal and glass door in Nancy (France), with a big transparent awning above it
Door of the Florence Baptistery called The Gates of Paradise, 14251452, gilded bronze, height: 5.2 m
There are many kinds of doors, with different purposes. The most common type is the single-leaf door, which consists of a single rigid panel that fills the doorway. There are many variations on this basic design, such as the double-leaf door or double door and French windows, which have two adjacent independent panels hinged on each side of the doorway.
A half door or Dutch door[8] or stable door is divided in half horizontally. Traditionally the top half opens so a worker can feed a horse or other animal while the bottom half remains closed to keep the animal inside. This style of door has been adapted for homes.
Saloon doors are a pair of lightweight swing doors often found in public bars, and especially associated with the American west. Saloon doors, also known as cafe doors, often use bidirectional hinges that close the door regardless of which direction it opens by incorporating springs. Saloon doors that only extend from knee-level to chest-level are known as batwing doors.
A blind door, Gibb door, or jib door has no visible trim or operable components. It blends with the adjacent wall in all finishes, to appear as part of the walla disguised door.[9]
A French door consists of a frame around one or more transparent or translucent panels (called lights or lites) that may be installed singly, in matching pairs, or even as series. A matching pair of these doors is called a French window, as it resembles a door-height casement window. When a pair of French doors is used as a French window, the application does not generally include a central mullion (as do some casement window pairs), thus allowing a wider unobstructed opening. The frame typically requires a weather strip at floor level and where the doors meet to prevent water ingress. An espagnolette bolt may let the head and foot of each door be secured in one movement. The slender window joinery maximizes light into the room and minimizes the visual impact of the doorway joinery when considered externally. The doors of a French window often open outward onto a balcony, porch, or terrace and they may provide an entrance to a garden.
A louvered door has fixed or movable wooden fins (often called slats or louvers) which permit open ventilation while preserving privacy and preventing the passage of light to the interior. Being relatively weak structures, they are most commonly used for wardrobes and drying rooms, where security is of less importance than good ventilation, although a very similar structure is commonly used to form window shutters. Double louvred doors were introduced into Seagate, built in Florida in 1929 by Gwendolyn and Powel Crosley, that provided the desired circulation of air with an added degree of privacy in that it is impossible to see through the fins in any direction.
A composite door is a single leaf door that can be solid or with glass, and is usually filled with high density foam. In the United Kingdom, composite doors are commonly certified to BS PAS 23/24[10] and be compliant with Secured by Design, an official UK police initiative.[11]
A steel security door is one which is made from strong steel, often for use on vaults and safe rooms to withstand attack. These may also be fitted with wooden outer panels to resemble standard internal and external doors.[12]
A flush door is a completely smooth door, having plywood or MDF fixed over a light timber frame, the hollow parts of which are often filled with a cardboard core material. Skins can also be made out of hardboards, the first of which was invented by William H Mason in 1924. Called Masonite, its construction involved pressing and steaming wood chips into boards. Flush doors are most commonly employed in the interior of a dwelling, although slightly more substantial versions are occasionally used as exterior doors, especially within hotels and other buildings containing many independent dwellings.
A moulded door has the same structure as that of flush door. The only difference is that the surface material is a moulded skin made of MDF. Skins can also be made out of hardboards.
A ledge and brace door often called board and batten doors are made from multiple vertical boards fixed together by two or more horizontal timbers called ledges (or battens)and sometimes kept square by additional diagonal timbers called braces.
A wicket door is a pedestrian door built into a much larger door allowing access without requiring the opening of the larger door. Examples might be found on the ceremonial door of a cathedral or in a large vehicle door in a garage or hangar.
A bifold door is a unit that has several sections, folding in pairs. Wood is the most common material, and doors may also be metal or glass. Bifolds are most commonly made for closets, but may also be used as units between rooms. Bi-fold doors are essentially now doors that let the outside in. They open in concert; where the panels fold up against one another and are pushed together when opened. The main door panel (often known as the traffic door) is accompanied by a stack of panels that fold very neatly against one another when opened fully, which almost look like room dividers.[13]
A sliding glass door, sometimes called an Arcadia door or patio door, is a door made of glass that slides open and sometimes has a screen (a removable metal mesh that covers the door).
Australian doors are a pair of plywood swinging doors often found in Australian public houses. These doors are generally red or brown in color and bear a resemblance to the more formal doors found in other British Colonies' public houses.
A false door is a wall decoration that looks like a window. In ancient Egyptian architecture, this was a common element in a tomb, the false door representing a gate to the afterlife. They can also be found in the funerary architecture of the desert tribes (e.g., Libyan Ghirza).
A doormat (also called door mat) is a mat placed typically in front of or behind a door of a home. This practice originated so that mud and dirt would be less prevalent on floors inside a building.
Most doors are hinged along one side to allow the door to pivot away from the doorway in one direction, but not the other. The axis of rotation is usually vertical. In some cases, such as hinged garage doors, the axis may be horizontal, above the door opening.
Doors can be hinged so that the axis of rotation is not in the plane of the door to reduce the space required on the side to which the door opens. This requires a mechanism so that the axis of rotation is on the side other than that in which the door opens. This is sometimes the case in trains or airplanes, such as for the door to the toilet, which opens inward.
A swing door has special single-action hinges that allow it to open either outwards or inwards, and is usually sprung to keep it closed.
French doors are derived from an original French design called the casement door. It is a door with lites where all or some panels would be in a casement door. A French door traditionally has a moulded panel at the bottom of the door. It is called a French window when used in a pair as double-leaved doors with large glass panels in each door leaf, and in which the doors may swing out (typically) as well as in.
A Mead door, developed by S Mead of Leicester, swings both ways. It is susceptible to forced entry due to its design.
A Dutch door or stable door consists of two halves. The top half operates independently from the bottom half. A variant exists in which opening the top part separately is possible, but because the lower part has a lip on the inside, closing the top part, while leaving the lower part open, is not.
A garden door resembles a French window (with lites), but is more secure because only one door is operable. The hinge of the operating door is next to the adjacent fixed door and the latch is located at the wall opening jamb rather than between the two doors or with the use of an espagnolette bolt.
It is often useful to have doors which slide along tracks, often for space or aesthetic considerations.
A bypass door is a door unit that has two or more sections. The doors can slide in either direction along one axis on parallel overhead tracks, sliding past each other. They are most commonly used in closets to provide access one side of the closet at a time. Doors in a bypass unit overlap slightly when viewed from the front so they don't have a visible gap when closed.
Doors which slide inside a wall cavity are called pocket doors. This type of door is used in tight spaces where privacy is also required. The door slab is mounted to roller and a track at the top of the door and slides inside a wall.
Sliding glass doors are common in many houses, particularly as an entrance to the backyard. Such doors are also popular for use for the entrances to commercial structures, although they are not counted as fire exit doors. The door that moves is called the "active leaf", while the door that remains fixed is called the "inactive leaf".
A revolving door has several wings or leaves, generally four, radiating from a central shaft, forming compartments that rotate about a vertical axis. A revolving door allows people to pass in both directions without colliding, and forms an airlock maintaining a seal between inside and out.
A pivot door, instead of hinges, is supported on a bearing some distance away from the edge, so that there is more or less of a gap on the pivot side as well as the opening side. In some cases the pivot is central, creating two equal openings.
A high-speed door is a very fast door some with opening speeds of up to 4 m/s, mainly used in the industrial sector where the speed of a door has an effect on production logistics, temperature and pressure control. high-speed clean room doors are used in pharmaceutical industries for the special curtain and stainless steel frames. They guarantee the tightness of all accesses. The powerful high-speed doors have a smooth surface structure and no protruding edges. Therefore, they can be easily cleaned and depositing of particles is largely excluded.
High-speed doors are made to handle a high number of openings, generally more than 200,000 a year. They must be built with heavy duty parts and counterbalance systems for speed enhancement and emergency opening function. The door curtain was originally made of PVC, but was later also developed in aluminium and acrylic glass sections. High Speed refrigeration and cold room doors with excellent insulation values was also introduced with the Green and Energy saving requirements.
In North America, the Door and Access Systems Manufacturing Association (DASMA) defines high-performance doors as non-residential, powered doors, characterized by rolling, folding, sliding or swinging action, that are either high-cycle (minimum 100 cycles/day) or high-speed (minimum 20 inches(508 mm)/second), and two out of three of the following: made-to-order for exact size and custom features, able to withstand equipment impact (break-away if accidentally hit by vehicle), or able to sustain heavy use with minimal maintenance.
Automatically opening doors are powered open and closed either by electricity, spring, or both. There are several methods by which an automatically opening door is activated:
A sensor detects traffic is approaching. Sensors for automatic doors are generally:
A pressure sensor e.g., a floor mat which reacts to the pressure of someone standing on it.
An infrared curtain or beam which shines invisible light onto sensors; if someone or something blocks the beam the door is triggered open.
A motion sensor which uses low-power microwave radar for the same effect.
A remote sensor (e.g. based on infrared or radio waves) can be triggered by a portable remote control, or is installed inside a vehicle. These are popular for garage doors.
A switch is operated manually, perhaps after security checks. This can be a push button switch or a swipe card.
The act of pushing or pulling the door triggers the open and close cycle. These are also known as power-assisted doors.
In addition to activation sensors, automatically opening doors are generally fitted with safety sensors. These are usually an infrared curtain or beam, but can be a pressure mat fitted on the swing side of the door. The safety sensor prevents the door from colliding with an object by stopping or slowing its motion. A mechanism in modern automatic doors ensures that the door can open in a power failure.
Up-and-over or overhead doors are often used in garages. Instead of hinges, it has a mechanism, often counterbalanced or sprung, so it can lift and rest horizontally above the opening. A roller shutter or sectional overhead door is one variant of this type.
A tambour door or roller door is an up-and-over door made of narrow horizontal slats and "rolls" up and down by sliding along vertical tracks and is typically found in entertainment centres and cabinets.
Inward opening doors are doors that can only be opened (or forced open) from outside a building. Such doors pose a substantial fire risk to occupants of occupied buildings when they are locked. As such doors can only be forced open from the outside, building occupants would be prevented from escaping. In commercial and retail situations, manufacturers include a mechanism that lets an inward opening door open outwards in an emergency (often a regulatory requirement). This is called a 'breakaway' feature. Pushing the door outward at its closed position, through a switch mechanism, disconnects power to the latch and lets the door swing outward. Returning the door to the closed position restores power.
Rebated doors, a term chiefly used in Britain, are double doors having a lip or overlap (i.e. a Rabbet) on the vertical edge(s) where they meet. Fire-rating can be achieved with an applied edge-guard or astragal molding on the meeting stile, in accordance with the American Fire door.
Evolution Door is a trackless door that moves in the same closure level as a sliding door. The system is an invention of the Austrian artist Klemens Torggler. It is a further development of the Drehplattentr [de] that normally consists of two rotatable, connected panels which move to each other when opening.[14]
Architectural doors have numerous general and specialized uses. Doors are generally used to separate interior spaces (closets, rooms, etc.) for convenience, privacy, safety, and security reasons. Doors are also used to secure passages into a building from the exterior, for reasons of climate control and safety.[15]
Doors also are applied in more specialized cases:
A Blast-proof door is constructed to allow access to a structure as well as to provide protection from the force of explosions.
A garden door is any door that opens to a backyard or garden. This term is often used specifically for French windows, double French doors (with lites instead of panels), in place of a sliding glass door. The term also may refer to what is known as patio doors.[citation needed]
A jib door is a concealed door, whose surface reflects the moldings and finishes of the wall. These were used in historic English houses, mainly as servants' doors.[citation needed]
A pet door (also known as a cat flap or dog door) is an opening in a door to allow pets to enter and exit without the main door's being opened. It may be simply covered by a rubber flap, or it may be an actual door hinged on the top that the pet can push through. Pet doors may be mounted in a sliding glass door as a new (permanent or temporary) panel. Pet doors may be unidirectional, only allowing pets to exit. Additionally, pet doors may be electronic, only allowing animals with a special electronic tag to enter.
A water door or water entrance, such as those used in Venice, Italy, is a door leading from a building built on the water, such as a canal, to the water itself where, for example, one may enter or exit a private boat or water taxi.[16][17]
Panel doors, also called stile and rail doors, are built with frame and panel construction. EN 12519 is describing the terms which are officially used in European Member States. The main parts are listed below:
Stiles Vertical boards that run the full height of a door and compose its right and left edges. The hinges are mounted to the fixed side (known as the "hanging stile"), and the handle, lock, bolt or latch are mounted on the swinging side (known as the "latch stile").
Rails Horizontal boards at the top, bottom, and optionally in the middle of a door that join the two stiles and split the door into two or more rows of panels. The "top rail" and "bottom rail" are named for their positions. The bottom rail is also known as "kick rail". A middle rail at the height of the bolt is known as the "lock rail", other middle rails are commonly known as "cross rails".
Mullions Smaller optional vertical boards that run between two rails, and split the door into two or more columns of panels, the term is used sometimes for verticals in doors, but more often (UK and Australia) it refers to verticals in windows.
Muntin Optional vertical members that divide the door into smaller panels.
Panels Large, wider boards used to fill the space between the stiles, rails, and mullions. The panels typically fit into grooves in the other pieces, and help to keep the door rigid. Panels may be flat, or in raised panel designs. Can be glued in or stay as a floating panel.
Light a piece of glass used in place of a panel, essentially giving the door a window.
Also known as ledges and braced, Board and batten doors are an older design consisting primarily of vertical slats:
Planks Boards wider than 9" that extend the full height of the door, and are placed side by side filling the door's width.
Ledges and braces Ledges extend horizontally across the door which the boards are affixed to. The ledges hold the planks together. When diagonally they are called braces which prevent the door from skewing. On some doors, especially antique ones, the ledges are replaced with iron bars that are often built into the hinges as extensions of the door-side plates.
Impact-resistant doors have rounded stile edges to dissipate energy and minimize edge chipping, scratching and denting. The formed edges are often made of an engineered material. Impact-resistant doors excel in high traffic areas such as hospitals, schools, hotels and coastal areas.
This type consists of a solid timber frame, filled on one face, face with Tongue and Grooved boards. Quite often used externally with the boards on the weather face.
Many modern doors, including most interior doors, are flush doors:
Stiles and rails As above, but usually smaller. They form the outside edges of the door.
Core material: Material within the door used simply to fill space, provide rigidity and reduce drumminess.
Hollow-core Often consists of a lattice or honeycomb made of corrugated cardboard, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core flush doors are commonly used as interior doors.
Lock block A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
Stave-core Consists of wooden slats stacked upon one another in a manner similar to a board and batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
Solid-core Can consist of low-density particle board or foam used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation and strength.
Skin The front and back faces of the door are then covered with wood veneer, thin plywood, sheet metal, fiberglass, or vinyl. The wooden materials are usually layered with the grain alternating direction between layers to prevent warping. Fiberglass and metal-faced doors are sometimes given a layer of cellulose so that they may be stained to look like wood.
Stiles and rails As above, but usually smaller. They form the outside edges of the door.
Core material: Material within the door used simply to fill space, provide rigidity and reduce druminess.
Hollow-core Often consists of a lattice or honeycomb made of corrugated cardboard, extruded polystyrene foam, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core molded doors are commonly used as interior doors.[18]
Lock block A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
Stave-core Consists of wooden slats stacked upon one another in a manner similar to a board & batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
Solid-core Can consist of low-density particle board or foam used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation and strength.
Skin The front and back faces of the door are covered with HDF / MDF skins.
Door swings For most of the world[citation needed], door swings, or handing, are determined while standing on the outside or less secure side of the door while facing the door (i.e., standing on the side requiring a key to open, going from outside to inside, or from public to private).
It is important to get the hand and swing correct on exterior doors, as the transom is usually sloped and sealed to resist water entry, and properly drain. In some custom millwork (or with some master carpenters), the manufacture or installer bevels the leading edge (the first edge to meet the jamb as the door closes) so that the door fits tight without binding. Specifying an incorrect hand or swing can make the door bind, not close properly, or leak. Fixing this error is expensive or time-consuming. In North America, many doors now come with factory-installed hinges, pre-hung on the jamb and sills.
While facing the door from the outside or less secure side, if the hinge is on the right side of the door, the door is "right handed"; or if the hinge is on the left, it is "left handed". If the door swings toward you, it is "reverse swing"; or if the door swings away from you, it is "Normal swing".
In other words, - In the United States:
In the United States: - Left hand hinge (LHH): Standing outside (or on the less secure side, or on the public side of the door), the hinges are on the left and the door opens in (away from you).
Left hand hinge (LHH): Standing outside (or on the less secure side, or on the public side of the door), the hinges are on the left and the door opens in (away from you).
Right hand hinge (RHH): Standing outside (or on the less secure side), the hinges are on the right and the door opens in (away from you).
Left hand reverse (LHR): Standing outside the house (or on the less secure side), the hinges are on the left, knob on right, on opening the door it swings towards you (i.e. the door swings open towards the outside, or "outswing")
Right hand reverse (RHR): Standing outside the house (i.e. on the less secure side), the hinges are on the right, knob on left, opening the door by pulling the door towards you (i.e. open swings to the outside, or "outswing")
In Europe: - One of the oldest DIN standard applies: DIN 107 "Building construction; identification of right and left side" (first 192205, current 1974-04) defines that doors are categorized from the side where the door hinges can be seen. If the hinges are on the left, it is a DIN Left door (DIN links, DIN gauche), if the hinges are on the right, it is a DIN Right door (DIN rechts, DIN droite). The DIN Right and DIN Left marking are also used to categorize matching installation material such as mortise locks (referenced in DIN 107). The European Standard DIN EN 12519 "Windows and pedestrian doors. Terminology" includes these definitions of orientation.
One of the oldest DIN standard applies: DIN 107 "Building construction; identification of right and left side" (first 192205, current 1974-04) defines that doors are categorized from the side where the door hinges can be seen. If the hinges are on the left, it is a DIN Left door (DIN links, DIN gauche), if the hinges are on the right, it is a DIN Right door (DIN rechts, DIN droite). The DIN Right and DIN Left marking are also used to categorize matching installation material such as mortise locks (referenced in DIN 107). The European Standard DIN EN 12519 "Windows and pedestrian doors. Terminology" includes these definitions of orientation.
In Australia: - The "refrigerator rule" applies, and a refrigerator door is not opened from the inside. If the hinges are on the right then it is a right hand (or right hung) door. (Australian Standards for Installation of Timber Doorsets, AS 19091984 pg 6.)
The "refrigerator rule" applies, and a refrigerator door is not opened from the inside. If the hinges are on the right then it is a right hand (or right hung) door. (Australian Standards for Installation of Timber Doorsets, AS 19091984 pg 6.)
In public buildings, exterior doors open to the outside to comply with applicable fire codes. In a fire, a door that opens inward could cause a crush of people who can't open it.[19]
Wooden doors including solid wood doors are a top choice for many homeowners, largely because of the aesthetic qualities of wood. Many wood doors are custom-made, but they have several downsides: their price, their maintenance requirements (regular painting and staining) and their limited insulating value[20] (R-5 to R-6, not including the effects of the glass elements of the doors). Wood doors often have an overhang requirement to maintain a warranty. An overhang is a roof, porch area or awning that helps to protect the door and its finish from UV rays.
Steel doors are another major type of residential front doors; most of them come with a polyurethane or other type of foam insulation core a critical factor in a building's overall comfort and efficiency. Steel doors mostly in default comes along with frame and lock system, which is a high cost efficiency factor compared to Wooden doors.
Most modern exterior walls provide thermal insulation and energy efficiency, which can be indicated by the Energy Star label or the Passive House standards. Premium composite (including steel doors with a thick core of polyurethane or other foam), fiberglass and vinyl doors benefit from the materials they are made from, from a thermal perspective.
But there are very few door models with an R-value close to 10 (which is far less than the R-40 walls or the R-50 ceilings of super-insulated buildings Passive Solar and Zero Energy Buildings). Typical doors are not thick enough to provide very high levels of energy efficiency.
Many doors may have good R-values at their center, but their overall energy efficiency is reduced because of the presence of glass and reinforcing elements, or because of poor weatherstripping and the way the door is manufactured.
Door weatherstripping is particularly important for energy efficiency. German-made passive house doors use multiple weatherstrips, including magnetic strips, to meet higher standards. These weatherstrips reduce energy losses due to air leakage.
Standard door sizes in the US run along 2" increments. Customary sizes have a height of 78" (1981 mm) or 80" (2032 mm) and a width of 18" (472 mm), 24" (610 mm), 26" (660 mm), 28" (711 mm), 30" (762 mm) or 36" (914 mm).[21] Most residential passage (room to room) doors are 30" x 80" (762 mm x 2032 mm).
A standard US residential (exterior) door size is 36" x 80" (91 x 203 cm). Interior doors for wheelchair access must also have a minimum width of 3'-0" (91 cm). Residential interior doors are often somewhat smaller being 6'-8" high, as are many small stores, offices, and other light commercial buildings. Larger commercial, public buildings and grand homes often use doors of greater height. Older buildings often have smaller doors.
Thickness: Most pre-fabricated doors are 1 3/8" thick (for interior doors) or 1 3/4" (exterior).
Closets: small spaces such as closets, dressing rooms, half-baths, storage rooms, cellars, etc. often are accessed through doors smaller than passage doors in one or both dimensions but similar in design.
Garages: Garage doors are generally 7'-0" or 8'-0" wide for a single-car opening. Two car garage doors (sometimes called double car doors) are a single door 16'-0". Because of size and weight these doors are usually sectional. That is split into four or five horizontal sections so that they can be raised more easily and don't require a lot of additional space above the door when opening and closing. Single piece double garage doors are common in some older homes.
Standard DIN doors are defined in DIN 18101 (published 195507, 198501, 2014-08). Door sizes are also given in the construction standard for wooden door panels (DIN 68706-1). The DIN commission created the harmonized European standard DIN EN 14351-1 for exterior doors and DIN EN 14351-2 for interior doors (published 200607, 2010-08), which define requirements for the CE marking and provide standard sizes by examples in the appendix.
The DIN 18101 standard has a normative size (Nennma) slightly larger than the panel size (Trblatt) as the standard derives the panel sizes from the normative size being different single door vs double door and molded vs unmolded doors. DIN 18101/1985 defines interior single molded doors to have a common panel height of 1985 mm (normativ height 2010 mm) at panel widths of 610 mm, 735 mm, 860 mm, 985 mm, 1110 mm, plus a larger door panel size of 1110 mm x 2110 mm.[22] The newer DIN 18101/2014 drops the definition of just five standard door sizes in favor of a basic raster running along 125 mm increments where the height and width are independent. Panel width may be in the range 485 mm to 1360 mmm, and the height may be in the range of 1610 mm to 2735 mm.[23] The most common interior door is 860 mm x 1985 mm (33.8" x 78.1").
A diagram illustrating the components of a panel door
When framed in wood for snug fitting of a door, the doorway consists of two vertical jambs on either side, a lintel or head jamb at the top, and perhaps a threshold at the bottom. When a door has more than one movable section, one of the sections may be called a leaf. See door furniture for a discussion of attachments to doors such as door handles, doorknobs, and door knockers.
Lintel A horizontal beam above a door that supports the wall above it. (Also known as a header)
Jambs or legs The vertical posts that form the sides of a door frame, where the hinges are mounted, and with which the bolt interacts.
Sill (for exterior doors) A horizontal sill plate below the door that supports the door frame. Similar to a Window Sill but for a door
Threshold (for exterior doors) A horizontal plate below the door that bridges the crack between the interior floor and the sill.
Doorstop a thin slat built inside the frame to prevent a door from swinging through when closed, an act which might break the hinges.
Architrave The decorative molding that outlines a door frame. (called an Archivolt if the door is arched). Called door casing or brickmold in North America.
Pair of door knobs in the Galerie dore de la Banque de France of the Htel de Toulouse (Paris)
Door furniture or hardware refers to any of the items that are attached to a door or a drawer to enhance its functionality or appearance. This includes items such as hinges, handles, door stops, etc.
Door safety relates to prevention of door-related accidents. Such accidents take place in various forms, and in a number of locations; ranging from car doors to garage doors. Accidents vary in severity and frequency. According to the National Safety Council in the United States, around 300,000 door-related injuries occur every year.[24]
The types of accidents vary from relatively minor cases where doors cause damage to other objects, such as walls, to serious cases resulting in human injury, particularly to fingers, hands, and feet. A closing door can exert up to 40 tons per square inch of pressure between the hinges.[citation needed] Because of the number of accidents taking place, there has been a surge in the number of lawsuits. Thus organisations may be at risk when car doors or doors within buildings are unprotected.
...It is essential that children's fingers be protected from being crushed or otherwise injured in the hinge space of a swinging door or gate. There are simple devices available to attach to the hinge side, ensuring that this type of injury does not occur. As the door closes, the hand is pushed out of the opening, away from harm. In addition, young children are vulnerable to injury when they fall against the other (hinged) side of doors and gates, striking projected hinges. Piano hinges are not recommended to alleviate this problem as they tend to sag over time with heavy use. Instead, an inexpensive device fitting over hinges is available on the market and should be used to ensure safety...[25]
Whenever a door is opened outwards there is a risk that it could strike another person. In many cases this can be avoided by architectural design which favors doors which open inwards into rooms (from the perspective of a common area such as a corridor, the door opens outwards). In cases where this is infeasible, it may be possible to avoid an accident by placing vision panels in the door.[26]
However, inward-hinged doors can also escalate an accident by preventing people from escaping the building: people inside the building may press against the doors, and thus prevent the doors from opening. Related accidents include:
Today, the exterior doors of most large (especially public) buildings open outward, while interior doors such as doors to individual rooms, offices, suites, etc. open inward, as do many exterior doors of houses, particularly in North America.
Doorstops are simple devices that prevent a door from contacting and possibly damaging another object (typically a wall). They may either absorb the force of a moving door, or hold the door against unintended motion.
Door guards (hinge guards, anti-finger trapping devices, or finger guards) help prevent finger trapping accidents, as doors pose a risk to children, especially when closing. Door guards protect fingers in door hinges by covering the hinge-side gap of an open door, typically with a piece of rubber or plastic that wraps from the door frame to the door. Other door safety products eject the fingers from the push side of the door as it closes.
There are various levels of door protection. Anti-finger trapping devices in front may leave the rear hinge pin side of doors unprotected. Full door protection uses front and rear anti-finger trapping devices and ensures the hinge side of a door is fully isolated. A risk assessment of the door determines the appropriate level of protection.
There is also handle-side door protection, which prevents the door from slamming shut on the frame, which can cause injury to fingers/hands.
A safety door prevents finger injuries near the hinges without using door guards. Rather than cover the danger area, the shape of the door changes to prevent an accessible gap forming the first place. A circular ("bull-nose" shaped) extension to the door moves in and out of a cavity as the door opens and closes. This prevents someone from injuring any part of a hand near the hingesinside or outside. These doors have an operating range of slightly over 90 degrees, so their use is limited to where they come into contact with a side wall when fully open (or where they can be prevented from opening too far by a doorstop).
Glass doors pose the risk of unintentional collision if a person is unaware there is a door, or thinks it is open when it is not. This risk is greater with sliding glass doors because they often have large single panes that are hard to see. Stickers or other types of warnings on the glass surface make it more visible and help prevent injury. In the UK, Regulation 14 of the Workplace (Health and Safety Regulations) 1992 requires that builders mark windows and glass doors to make them conspicuous. Australian Standards: AS1288 and AS2208 require that glass doors be made of laminated, tempered, or toughened glass.
Buildings often have special purpose doors that automatically close to prevent the spread of fire and smoke. Fire doors that are improperly installed or tampered with can increase risk during a fire. Sometimes, door closer mechanisms ensure fire doors remain closed.
An additional fire risk is that doors may prevent access to emergency services personnel coming to fight the fire and rescue occupants, etc. Fire fighters must use door breaching techniques in these situations to gain access.
Doors in public buildings often have panic bars, which open the door in response to anyone pressing against the bar from the inside in the event of a fire or other emergency.
Vehicle doors present an increased risk of trapping hands or fingers due to the proximity of occupants. In some car accidents, injury to occupants from the movement of car doors occurs.[citation needed]
Bicyclists cycling on public roads risk dooring: collision with an abruptly opened vehicle door. Because cyclists often ride near parked cars alongside the road, they are particularly vulnerable.
In aircraft, doors from pressurized sections to un-pressurized compartments or the exterior can pose risk if they open during flight. Air may rush out of the fuselage with sufficient velocity to eject unsecured occupants, cargo, and other items, and drastic pressure differences between compartments may make aircraft floors or other interior partitions fail. These concerns are typically mitigated with plug doors, which open in towards the pressurized compartment and are forced into their door frames by the difference in air pressure. Most cabin doors are of this type, but cargo doors typically open outward to maximise interior space, and require hefty locking mechanisms to overcome internal pressure and prevent explosive decompression.
A number of aircraft accidents involved outward-opening door failures, including:
^ a b Needham, Joseph. (1986). Science and Civilization in China: Volume 4, Part 2, Mechanical Engineering. Taipei: Caves Books, Ltd.
^ Architecture, European Copper Institute; "Archived copy". Archived from the original on 2012-10-09. Retrieved 2012-09-12.CS1 maint: archived copy as title (link)
^ "Archived copy". Archived from the original on 2018-01-03. Retrieved 2015-02-24.CS1 maint: archived copy as title (link) Door design ideas
^ Nicholson, Peter (1841). The New and Improved Practical Builder. London: Thomas Kelly. pp. 9798.
^ "Doors and Locks". Secured by Design. Police Crime Prevention Initiative. Retrieved 29 October 2019.
^ Exterior Doors; Energy.gov; "Archived copy". Archived from the original on 2015-03-04. Retrieved 2015-03-05.CS1 maint: archived copy as title (link)
^ USA General Services Administration Child Care Center Design Guide, June 1998
^ Home Safety Guidelines for Architects & Builders, NBS GCR 78-156, BOSTI, December 1978
This article incorporates text from a publication now in the public domain: Spiers, Richard Phen (1911). "Door". In Chisholm, Hugh (ed.). Encyclopdia Britannica. 8 (11th ed.). Cambridge University Press. pp. 419420.
End Release - What Does an End Release Do?
What Does an End Release Do? - An end release can be applied to a beam element.
An end release can be applied to a beam element.
An end release will allow either or both ends of a beam element to rotate about or translate along one or more of the local axes of the beam.
Applying an End Release: - If you select one or more beam elements using the "Selection: Select: Lines" command and right click in the display area, you can select the "Add" pull-out menu and select the "Beam End Releases..." command to add an end release to each beam element.
If you select one or more beam elements using the "Selection: Select: Lines" command and right click in the display area, you can select the "Add" pull-out menu and select the "Beam End Releases..." command to add an end release to each beam element.
Activate the checkboxes in the "I Node" and "J Node" sections to release the rotation or translation of that node in one of the local directions. "T1" refers to the translation along the local 1 axis. "R1" refers to the rotation about the local 1 axis. You can use the buttons to the right to set the releases to certain values.
Tip - The orientation of the beam elements can be displayed using the "View: Options: Element Orientations" pull-out menu. Axis 1 points in the direction from the "I Node" to the "J Node". If axis 1 needs to be reversed for some elements, this can be done by selecting the elements ("Selection: Select: Lines"), right-clicking, and choosing "Invert I and J Nodes".
The orientation of the beam elements can be displayed using the "View: Options: Element Orientations" pull-out menu. Axis 1 points in the direction from the "I Node" to the "J Node". If axis 1 needs to be reversed for some elements, this can be done by selecting the elements ("Selection: Select: Lines"), right-clicking, and choosing "Invert I and J Nodes".
Note - In a normal beam member, the displacement and rotation result is continuous from one element to the next. Since end releases free a translation or rotation at a node, there is a theoretical step-change in that result at the node. For example, a rotational end release creates a hinge. The rotation angle at the end of one beam does not equal the rotation angle at the start of the next beam. (See figure (a) and (b) below.) However, the FEA results give just one value of displacement and rotation at a node. Therefore, the effect of the end release will not be visible at the node. (See figure (c) below.) If necessary, add an extra node close to the end release to see the effect more clearly.
In a normal beam member, the displacement and rotation result is continuous from one element to the next. Since end releases free a translation or rotation at a node, there is a theoretical step-change in that result at the node. For example, a rotational end release creates a hinge. The rotation angle at the end of one beam does not equal the rotation angle at the start of the next beam. (See figure (a) and (b) below.) However, the FEA results give just one value of displacement and rotation at a node. Therefore, the effect of the end release will not be visible at the node. (See figure (c) below.) If necessary, add an extra node close to the end release to see the effect more clearly.
(a) Fixed-fixed beam with a hinge point at 1 and 2.
(b) The theoretical rotation or slope of the beams. Note how the result is discontinuous at the hinge points.
(c) Since there is only one rotation result in the analysis at the hinge points 1 and 2, the rotation results are presented as continuous. The length of the "step" (shown by dashed lines in the figure) is determined by the size of the element with the end release.
Since the internal shear forces and moments are calculated at each node on each element, discontinuities can be displayed in these results.
feature - noun
noun - a prominent or conspicuous part or characteristic: Tall buildings were a new feature on the skyline.
a prominent or conspicuous part or characteristic: Tall buildings were a new feature on the skyline.
something offered as a special attraction: This model has several added features.
Also called feature film . the main motion picture in a movie program: What time is the feature?
any part of the face, as the nose, chin, or eyes: prominent features.
features, the face; countenance: to compose one's features for the photographers.
the form or cast of the face: delicate of feature.
a column, cartoon, etc., appearing regularly in a newspaper or magazine.
verb (used with object), featured, featuring.
to be a feature or distinctive mark of: It was industrial expansion that featured the last century.
to make a feature of; give prominence to: to feature a story or picture in a newspaper.
to delineate the main characteristics of; depict; outline.
Informal. to conceive of; imagine; fancy: He couldn't quite feature himself as a bank president.
Older Use. to resemble in features; favor.
SEE MORESEE LESS - verb (used without object), featured, featuring.
verb (used without object), featured, featuring.
to play a major part. - QUIZZES
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Origin of feature
Origin of feature - First recorded in 13501400; Middle English feture, from Anglo-French, Middle French faiture, from Latin factra formation, manufacture. See fact, -ure
First recorded in 13501400; Middle English feture, from Anglo-French, Middle French faiture, from Latin factra formation, manufacture. See fact, -ure
synonym study for feature - 1. Feature, characteristic, peculiarity refer to a distinctive trait of an individual or of a class. Feature suggests an outstanding or marked property that attracts attention: Complete harmony was a feature of the convention. Characteristic means a distinguishing mark or quality (or one of such) always associated in one's mind with a particular person or thing: Defiance is one of his characteristics. Peculiarity means that distinct or unusual characteristic that marks off an individual in the class to which he, she, or it belongs: A blue-black tongue is a peculiarity of the chow chow.
1. Feature, characteristic, peculiarity refer to a distinctive trait of an individual or of a class. Feature suggests an outstanding or marked property that attracts attention: Complete harmony was a feature of the convention. Characteristic means a distinguishing mark or quality (or one of such) always associated in one's mind with a particular person or thing: Defiance is one of his characteristics. Peculiarity means that distinct or unusual characteristic that marks off an individual in the class to which he, she, or it belongs: A blue-black tongue is a peculiarity of the chow chow.
OTHER WORDS FROM feature - transfeature, verb (used with object), transfeatured, transfeaturing.underfeature, noun
transfeature, verb (used with object), transfeatured, transfeaturing.underfeature, noun
VOCAB BUILDER - What is a basic definition of feature?
What is a basic definition of feature? - A feature is a distinctive trait or a special attraction. Feature can also mean to give special attention to something. The word feature has several other senses as a noun and a verb.
A feature is a distinctive trait or a special attraction. Feature can also mean to give special attention to something. The word feature has several other senses as a noun and a verb.
A feature is a unique quality or characteristic that something has.
Real-life examples: Elaborately colored tail feathers are peacocks most well-known feature. Earth has many features, such as a particular atmosphere, abundance of water, and temperature that make it able to sustain life. Platypuses have many features that are unusual in mammals, such as a bill and the ability to lay eggs.
Used in a sentence: My house is really boring and doesnt have any cool features that set it apart from every other house in the neighborhood.
Feature can also mean a special attraction or enticing quality that something has. Not all features are necessarily useful and, especially in advertising, they are often added to amaze rather than perform a useful function.
Real-life examples: Smartphones often have many features, such as Bluetooth technology, a camera, and many other additions that entice customers to buy it. People who buy cars are often interested in extra features, such as rear-view cameras, automated steering, and heated seats.
Used in a sentence: I always go for cameras with lots of neat features, like custom white balancing.
As a verb, feature means to draw special attention to something or to shine the spotlight on it. If something is featured, it is mentioned first, given the most time, advertised most heavily, or invested the most effort into.
Real-life examples: Movie advertising often features a big star on posters and in commercials even if the person is barely in the movie. The main event fight is usually featured by boxing or mixed martial arts promoters because it will attract the most ticket buyers.
Used in a sentence: I really like this song because it features the drummer the most.
Where does feature come from? - The first records of feature come from around 1350. It ultimately comes from the Latin factra, meaning formation or manufacture.
The first records of feature come from around 1350. It ultimately comes from the Latin factra, meaning formation or manufacture.
How is feature used in real life? - Feature is a common word that means a special trait something has or means to spotlight something.
Feature is a common word that means a special trait something has or means to spotlight something.
Not sure how I feel about the Apple Watch. Yes, some very cool features, but nothing your smartphone can't already do.
Odd feature of walk-through trains: if people are singing, you can hear them from the other end. Its like having the radio on quiet.
Todays show features a special message on behalf of everyone in the Jeopardy! family.
Alex taped shows through December 25th, 2020. They will air as he intended, in his honor.
Words related to feature - Example sentences from the Web for feature
Example sentences from the Web for feature - Publishers biggest differentiating features for advertisers are their audiences and the context within their ads will sit, said Alessandro De Zanche, founder of media consultancy ADZ Strategies.
Publishers biggest differentiating features for advertisers are their audiences and the context within their ads will sit, said Alessandro De Zanche, founder of media consultancy ADZ Strategies.
Along with that comes systemwide picture-in-picture support for videosanother feature that has made its way from iPadOSand a number of significant improvements to Messages, Maps, and other applications, as well as a new live translation app.
The feature, known as Maneuvering Characteristics Augmentation System, was designed to make the Max feel exactly the same to pilots as the earlier family of 737s known as the Next Generation.
Since then, Amazon Prime Video, Hulu, Instagram and Twitch have added watch party features.
Apple also debuted the Apple Watch SE, a lower-end model with fewer features that starts at $279.
Grindr introduced the feature themselves in October the same year and called it tribes.
Jourdan Dunn is the first sole black woman to feature on a British Vogue cover in 12 years.
Common sense is not a just a normative judgment about wisdom, but a structural feature of any functioning organization.
The brand logo turned out to feature a graceful archer on horseback, in a Tatar national costume, poised to shoot his arrow.
This is a feature by means of which it is always possible to distinguish the Great Horsetail from any other species.
Each is surrounded by a gelatinous capsule, which is its distinctive feature (Fig. 9).
He seemed to know right where to look, which was another feature of the play that I didn't sabe at the time.
In dramatic interpretation the voice is a much more significant feature relatively than is the detail of gesture in pantomime.
My coup-d'il assured me that it was practicable to give to this feature the character of a projecting under-jaw.
British Dictionary definitions for feature - feature
feature - / (fit) /
/ (fit) / - noun
noun - any one of the parts of the face, such as the nose, chin, or mouth
any one of the parts of the face, such as the nose, chin, or mouth
a prominent or distinctive part or aspect, as of a landscape, building, book, etc
the principal film in a programme at a cinema
an item or article appearing regularly in a newspaper, magazine, etca gardening feature
Also called: feature story a prominent story in a newspaper, etca feature on prison reform
a programme given special prominence on radio or television as indicated by attendant publicity
an article offered for sale as a special attraction, as in a large retail establishment
archaic general form or make-up - linguistics a quality of a linguistic unit at some level of descriptiongrammatical feature; semantic feature
linguistics a quality of a linguistic unit at some level of descriptiongrammatical feature; semantic feature
SEE MORESEE LESS - verb
verb - (tr) to have as a feature or make a feature of
(tr) to have as a feature or make a feature of
to give prominence to (an actor, famous event, etc) in a film or (of an actor, etc) to have prominence in a film
(tr) US informal to imagine; considerI can't feature that happening
SEE MORESEE LESS - Word Origin for feature
Word Origin for feature - C14: from Anglo-French feture, from Latin factra a making, from facere to make
C14: from Anglo-French feture, from Latin factra a making, from facere to make
Fill meaning - To fill is defined as to put as much as possible or to occupy.
To fill is defined as to put as much as possible or to occupy.
An example of to fill is putting as much salt into a salt shaker as will fit.
verb - 5
5 - 0
0 - The definition of fill is to supply what is needed, satisfy, close or put a person into.
The definition of fill is to supply what is needed, satisfy, close or put a person into.
An example of to fill is a pharmacy giving a prescription to a customer.
An example of to fill is a pregnant woman eating ice cream after having a craving for it.
An example of to fill is putting putty into a small wall hole and making it smooth.
An example of to fill is hiring someone for a position that was open at a company.
verb - 1
1 - 0
0 - To cover the surface of (an inexpensive metal) with a layer of precious metal, such as gold.
To cover the surface of (an inexpensive metal) with a layer of precious metal, such as gold.
Anything that fills or is used to fill; esp., earth, gravel, etc. used for filling a hole or depression.
noun - 0
0 - 0
0 - A piece of land artificially raised to a required level, as a railroad embankment.
A piece of land artificially raised to a required level, as a railroad embankment.
noun - 0
0 - 0
0 - Advertisement
Advertisement - A trading term that indicates that the customers order to buy or sell stocks, bonds, futures, or options has been successfully completed. Orders that are only partly filled are called partial fills.
A trading term that indicates that the customers order to buy or sell stocks, bonds, futures, or options has been successfully completed. Orders that are only partly filled are called partial fills.
(1) In a graphics program, to apply color to a graphics object such as a rectangle, circle or polygon. In a paint program, the fill function is depicted as a paint bucket icon. It is used to "paint" objects or the entire canvas.
Oxford English and Spanish Dictionary, Synonyms, and Spanish to English Translator
Meaning of from in English: - from
from - Pronunciation /frm/ /frm/
Pronunciation /frm/ /frm/ - preposition
preposition - 1Indicating the point in space at which a journey, motion, or action starts.
1Indicating the point in space at which a journey, motion, or action starts.
she began to walk away from him - More example sentences
More example sentences - I leapt from my bed
I leapt from my bed - he was turning the Chamberlain government away from appeasement
he was turning the Chamberlain government away from appeasement
She got a bad feeling in her stomach as she slowly got up from her bed and walked back to the stairs.
Amazingly, it took only five months for the Altea to make the journey from prototype to showroom.
The main journey I make is from Woodthorpe to Rawcliffe, where my girlfriend lives.
It's a five hour journey from Chichester, with train changes at Reading and Crewe.
Car journeys to and from the site would also be increased if the expansion was given the go-ahead.
It took the Councillor two hours to make the journey from Bury to Ramsbottom.
Not that you're bothered, but my journey to and from work is a two bus affair.
My Saturday evening journey from Kings Cross to York took no less than six hours!
The local rivals make the short journey across the border from Lancashire today.
The problems all occurred on the last leg of the journey from London Paddington back to Didcot.
Regular buses from Saranda make the journey, or you can haggle a price with a taxi driver.
We used to stop there at least four times a year in my childhood on the journeys to and from each grandmother.
It's only one of many benefits to sharing the driving on your regular journey to and from work.
Journeys to and from one of the hospitals will have to be made on the second and third journey of the ticket.
The Russian Soyuz is now the only ship capable of carrying crew to and from the space outpost.
It would not be possible for the Met not to be changed by the journey from Lawrence.
It was also said that one leg of a planned flight involved a journey from Manchester.
The final treat of the day was when our driver rose from the table and motioned for me to join him.
My observation is that only a small number of cars move from their spaces during the working day.
Bear in mind there's a lengthy one hour plus taxi journey from the airport into town.
1.1Indicating the distance between a particular place and another place used as a point of reference.
the ambush occurred 50 metres from a checkpoint - More example sentences
More example sentences - He said they were now staying a short distance from their home in a flat on the Down's Road.
He said they were now staying a short distance from their home in a flat on the Down's Road.
The car was seen by police a couple of hours later only a short distance from Mr Graiezevsky's road.
We often go to Hohai lake, which is walking distance from here and part of the old imperial grounds.
Who measured the distance from Earth to Mars and did they have to make sure the tape measure was rigid?
A site on Infirmary Road was rejected because of its distance from the city centre.
More than ever it's a question we must face, standing at a distance from the photocopier.
This leaves her with a loss of feeling in her limbs and means she has to use the car to travel any distance from her home.
It is five miles from St Andrews and a similar distance from a variety of beaches and scenic towns.
The car would need to travel only a short distance from the car park to pick up a fare.
It is a tool which can be used to design the network with the check on distances from three points.
Other sanctuaries of Demeter in Greece were located at some distance from town centres.
The length measured, using a ruler, was the distance from the base to the first flower on the stem.
The word sin was originally an archery term, being a unit of distance from the bull's eye.
Scores shall be determined according to the distance of the arrows from the flag stick.
I then measured an equal distance from both sides and marked the area to be cut out.
2Indicating the point in time at which a particular process, event, or activity starts.
More example sentences - the show will run from 10 a.m. to 2 p.m
the show will run from 10 a.m. to 2 p.m
3Indicating the source or provenance of someone or something.
I'm from Hackney - More example sentences
More example sentences - she rang him from the hotel
she rang him from the hotel - she demanded the keys from her husband
she demanded the keys from her husband - I am not in a position to indicate what roads will be funded from that source in the year.
I am not in a position to indicate what roads will be funded from that source in the year.
I must agree with Mr Derbyshire that clean energy from renewable sources is the way forward.
They have to get funding from somewhere, these sources for funds have to be big, and so have to be noticed.
The rest of the cash is being met by funds raised through the parish itself and grant money from other sources.
If they showed pictures of meetings, people would get ideas from other sources.
Therefore it is better to drink from a known and trusted source, rather than from a suspect bottle.
I only hope the logs used were from a renewable source, because man, there were a lot of 'em.
This translation from a medieval Anglo-Norman source gives a less cynical view on it.
Their identities have not been released but police sources say they are from Rayleigh.
He added that another appeal of the furniture was that it was sourced from sustainable forests.
You can go here and see images from his motion work and also some clips, but not many.
It is also called the Cork Tree, as an inferior cork is processed from its corky bark.
In the event of objections from members of the public, the consent would be subject to a public inquiry.
Money from any fundraising events in the pipeline will go towards extra items and running costs.
The event is run under the watchful eye of troops from the Royal Artillery Display Troop.
The event is organised by volunteers from the library to raise money to spend on community facility.
Analysts often use prices from various markets as indicators of potential events.
Top performers from all over the area have been brought together for the show.
Now his rescue bids have earned him a top life-saving award from the Royal Humane Society.
Let's observe our rights to support both teams whatever part of this fine island you are from.
3.1Indicating the date at which something was created.
a document dating from the thirteenth century - More example sentences
More example sentences - The oldest securely dated complete Korans we possess date only from the ninth century.
The oldest securely dated complete Korans we possess date only from the ninth century.
Customers are invited to pick up a copy of the brochure from the box office from that date.
He also tips a wink to counterparts in the brewing trade from centuries ago.
An old man with a walnut face and brocade robes rode by, seemingly from the last century.
It survives for us as a small, dark, fascinating vignette from the fourteenth century.
Many episodes from the late nineteenth century exemplify the crisis of liberalism.
4Indicating the starting point of a specified range on a scale.
men who ranged in age from seventeen to eighty-four
More example sentences - If we have a scale from one to ten, what are we going to do if we meet someone who is a twelve?
If we have a scale from one to ten, what are we going to do if we meet someone who is a twelve?
With prices ranging from a few rupees to a few hundred, the lamps make for a memorable buy.
Injuries range from serious lacerations to major fractures and head and spinal injuries.
Reviews were mixed, ranging from two stars in the Guardian to four in the film magazine Empire.
Anyone with a few hours to spare can join, and the current volunteers range in age from 18 up.
The timescales allowed to complete the recommendations ranges from two to five years.
The types of incidents the team deal with ranges from high to low level cases.
Up to ten children at a time would be housed overnight, with ages ranging from six weeks to five years.
4.1Indicating one extreme in a range of conceptual variations.
anything from geography to literature - More example sentences
More example sentences - AgriPower has developed a virtual landfill system that can produce electricity and heat by burning anything from nuts to old tires.
AgriPower has developed a virtual landfill system that can produce electricity and heat by burning anything from nuts to old tires.
Activities at the youth group include everything from sporting events to weekends away.
The exhibition features all things foodie from specialist ranges to top booze.
Is there a scale running from Not Believable to This Character is Now a Real Person?
The ideas range from the highly plausible to the vaguely intriguing to the obviously crackpot.
This ranges from casual remarks to serious agitation by the xenophobic right.
It contains a range of 120 ideas from chicken and noodle bake to a simple tuna sandwich.
All the tracks are original compositions and the music ranges from folk to acoustic jazz.
Its severity can range from a minor inconvenience to a fatal rhythm disturbance.
Attacks ranged from verbal abuse and being spat on to being pelted with stones and shot at with airguns.
It is among the largest in the country, ranging from farms to gold mines, gravel pits to forests.
Mourners ranged from the very young to pensioners who had lived their entire lives in the village.
Five bands wowed the crowds with musical styles ranging from country and western to rock and jazz.
Each band had a mere ten minutes to show off their talent and music ranged from rock to punk and nu-metal.
If found guilty, they face sanctions ranging from a small fine to being stripped of their posts.
They range from banker masons skilled in the hand carving of stone to experts in materials testing.
These range from stained glass and masonry through to steam engines and historic aircraft.
It has developed into a full flute choir incorporating the entire flute range from piccolo to bass.
Synonyms - by, made by, done by, carried out by, caused by, from, in, of
by, made by, done by, carried out by, caused by, from, in, of
5Indicating the point at which an observer is placed.
you can see the island from here - More example sentences
More example sentences - the ability to see things from another's point of view
the ability to see things from another's point of view
Christmas arrived and with it frost and snow on the mainland mountains visible from the island.
It's amazing to see the island from the waters, all classic hazy blue layers of skyscrapers.
I guess it must take a view from afar to observe what a self serving First Minister is.
The launches were observed from both sides and have no writing or identification marks on them.
He picked the place so he could observe the convoy from up close with his optic probe.
When you look at pictures of the earth from space the effect is even greater.
If you were able to see the Great Wall from space, you'd be able to see the bloody motorway system.
I am watching this drama unfold from a distance, but in a weird way I feel so close to it.
He says you must stand back and look at the tree from a distance to get an idea how tall it is.
She got so close to her face that from a distance it could have looked like they were smooching.
Newman watched events unfold from his perch in front of the computer screens.
Eyed from a distance, the steaks look spectacular as did the rugged, chunky chips.
On occasions I have waited and watched from a distance to see if anyone comes running to answer it.
As this had been dug into limestone, the mound would have been clearly visible from a distance.
Officers believe that from a distance, the mast would appear to be a lighting column.
But a menace we have until now seen only from a distance has stepped right up to face us.
What from a distance looked as if it may be a village turned out to be a huge rubbish dump.
It means not shedding flakes that are visible to other people from a distance of two feet.
The best place to view the giant from a distance is from a wide lay-by, just outside the village.
How many people could look at power from such close quarters and not grab it with both hands?
6Indicating the raw material out of which something is manufactured.
a paint made from a natural resin - More example sentences
More example sentences - These can be manufactured from arable crops like oil seed rape and sugar beet.
These can be manufactured from arable crops like oil seed rape and sugar beet.
Here is something more than raw material from which a successful literature was forged.
7Indicating separation or removal. - the party was ousted from power after sixteen years
the party was ousted from power after sixteen years
More example sentences - It had been the longest separation from the hills I'd suffered since I broke my ankle.
It had been the longest separation from the hills I'd suffered since I broke my ankle.
They were showered in debris as the house collapsed and Amanda was separated from her party.
They were the fabulous people responsible for the removal of the ads from this page!
He is also sceptical about the removal of minimum-wage workers from the tax net.
Imagine if, in December, the Board of Deputies case results in my removal from office.
This is despite regular spraying and the removal of diseased leaves from bush and ground.
Second, there has been the removal of proposed housing from the Blackfriars area.
It's goal is the removal of individual bias from determining the nature of reality.
His removal from command of the army he had forged had a calamitous effect on the morale of his men.
What the coup plotters wanted and still want is to take power away from the people.
For nearly a decade a group of people exiled from power during the Clinton years had been making plans.
Far from devolving decision making to local communities it would take power away from them.
The unique advantage of democracy is that it can remove such people from power.
That would be a really interesting way to erode power from the nation state.
I shall be absent from this space for the next six weeks, so a happy Christmas to all of you.
I think what stands out the most from the two journeys is the attitude of the staff on the trains.
Drivers come steaming up here all the time just to cut a few minutes from their journey.
The first offense will result in disqualification of the shooter from the event.
This was a deeply formative experience, dividing the fate of the island from the mainland.
They were taken from their natural parents and put in foster care, and some were even adopted.
8Indicating prevention. - the story of how he was saved from death
the story of how he was saved from death
More example sentences - If just one child is saved from death because of such a law then it can only be a good thing.
If just one child is saved from death because of such a law then it can only be a good thing.
A top police display dog was saved from choking to death by a quick-acting vet and a fast dash in a police car.
Can she and her ex-husband save themselves and their young son from certain death?
If we want to keep on sinning after we are saved from the law of sin and death, He will allow us to do so.
The Robin Hood pub has been saved from demolition but its future as a watering hole looks uncertain.
Three brave police officers risked their lives to save a woman from drowning.
The campaign and the Trust were acclaimed for helping save City from the threat of extinction.
The injunction prohibits Helm from using the name on his Website or in any commercial context.
It follows Barbara's decision to save a greyhound from being slaughtered in Spain.
I once caught a scarf in a lift door as it closed and only just managed to heave it free and save myself from a gruesome end.
He spoke pityingly, as if saving a bewildered tourist from a cultural faux pas.
What a sad fate for the nation that saved the world from fascism just 60 years ago.
In all fairness she is saving the children from a life of poverty and misery.
A woman has thanked the hero who saved her from a fire which destroyed the family home.
Supplies of serum were needed to save the isolated community from a terrible human tragedy.
Only the lack of policy comparison saves the First Minister from the outrage he deserves.
As they work back through his memories he desperately tries to save them from being destroyed.
The agents preventing activists from boarding planes were assisted by the airlines.
All our people are forbidden from engaging in the activities prohibited by the Act.
Anything at all that could be deemed useful in arms manufacture has been prohibited from import.
9Indicating a cause. - a child suffering from asthma
a child suffering from asthma - More example sentences
More example sentences - How are you supposed to tell if a neurotic dog feels it has benefited from its treatment?
How are you supposed to tell if a neurotic dog feels it has benefited from its treatment?
Surgery is an option for the minority of women who get little benefit from medical treatment.
It was nominated by people who have benefited from its work and seen the positive effect on the community.
The residents may indeed benefit from being under the wing of Croydon Council.
Those who benefit from positive discrimination gain access, but not those who don't.
My vegetables will benefit enormously from this very kind and generous action.
This means 185 of the schools in the county are now benefiting from this technology.
He has also benefited from being given a more expansive role under the Swede.
Many small businesses believe they are the last in line to benefit from competition in telecoms.
Meanwhile, the mayor's own tsunami fund is set to benefit from a couple of large donations.
Some annuals are slow to germinate and grow and benefit from an early sowing.
I want you to know that you may benefit from the love that an animal is capable of giving.
Drug addicts would benefit from the tests once they decided to kick the habit.
They believe that these children would benefit from being in mainstream education.
A Bill will be introduced to enable more young people to benefit from higher education.
Changes in view throughout the film come more from chance events than any deeper process.
They could even resolve the problems caused by emissions from their processes.
All we ask is that the owner provides us with some photographs to show that the tree came down from natural causes.
During the late period of slavery attempts were made to prevent infant deaths from tetanus.
The high number of deaths from cholera this year has exacerbated the emergency.
10Indicating a source of knowledge or the basis for one's judgement.
information obtained from papers, books, and presentations
More example sentences - We read that what's on and where can be obtained from the tourist information centre.
We read that what's on and where can be obtained from the tourist information centre.
She was allowed to obtain information from the patient and her medical notes.
Up to now much of your farming knowledge was gleaned from your parents and teachers.
I can say from first hand knowledge that there was not a player in his side that did not hate him.
Take the knowledge from the history of a thing and apply it to The NOW, to Yourself.
In one case, a young woman was convicted of neglect on the basis of evidence from a radiographer.
Can you actually speak from medical experience to use this as a basis of comparison?
This information seems to have been obtained from file notes which were not made available to us.
As far as I could gather from the local paper, all he does is take down, put up and modify speed humps.
Should they be more discerning about the sources they draw their information from?
Their injuries were so bad that police had to identify them from their fingerprints.
He said he needed more information from carnival organisers before he could quote the cost.
The data obtained from the analysis of polar structure is illustrated in Table XIV.
You realise what you have got from it and can identify others at earlier or differing stages in the process.
Data on birth characteristics were obtained from the Danish medical birth registry.
11Indicating a distinction. - these fees are quite distinct from expenses
these fees are quite distinct from expenses - More example sentences
More example sentences - Further, this third genus is manifestly different and distinct from the second.
Further, this third genus is manifestly different and distinct from the second.
They are quite strikingly different from the faces one sees in equivalent circles in London.
Here the landscape is quite different from the interior but no less rewarding.
It's called the cost of living, and it's quite different from the rate of inflation.
The whole place has been redecorated and looks quite different from how I remember it.
This is quite different from Europe, where eating on the slopes will cost you an arm and a leg.
You may end up writing books which are quite different from what you intended to write when you started out.
The position is quite different from that which appertained in the Ireland case.
We started off quite a bit different from where we had been at the open test.
One day, you could part own quite a different company from the one you invested in many years ago.
Barley Junction was quite a different station from the one I had left in the Suburbs.
So the logical form of the second sentence is quite different from the logical form of the first.
Its quite different from the Sokal hoax, for lots of reasons, as has been pointed out.
They were quite different from what she'd seen in the parts of town she frequented.
Writers often differ quite widely from each other over ethical issues and questions.
Indeed, why should there be a history of science distinct from the history of thought and action?
Is that not what is what is happening, as distinct from what is being said to happen?
How far have its actions, as distinct from its example, contributed to that end?
Do you have any objection to being named by your name, as distinct from by an initial?
Kant warned that enjoyment of beauty was distinct from other sorts of pleasure.
Phrases - from time to time
from time to time - Occasionally.
Occasionally. - Although he is now fluent in Bulgarian, Matt still confuses the odd word from time to time.
Although he is now fluent in Bulgarian, Matt still confuses the odd word from time to time.
More example sentences - Chances are you won't get one, but I understand that you feel the need - we all do from time to time.
Chances are you won't get one, but I understand that you feel the need - we all do from time to time.
Place on a high heat and bring to the boil, stirring from time to time.
Friday night was one of those pleasant surprises the Internet throws my way from time to time.
Pack little surprises from time to time like stickers, a novelty pen or a joke.
Sadly, having had to travel on the Tube from time to time, it doesn't happen.
Yet any organisation must examine itself and the way it works from time to time.
The people who run it are hardcore music fans, they actually let us play there from time to time.
The atmosphere is chilling and symbolic imagery crops up nicely from time to time.
We always like to hear of any other gardening tips you might have and will do our best to include them from time to time in this column.
from year to year - As time passes.
As time passes. - Normally, property is all about location on presumptuously called The World, the location changes from day to day, and the sea views change by the hour.
Normally, property is all about location on presumptuously called The World, the location changes from day to day, and the sea views change by the hour.
More example sentences - It has been a time of uncertainty about the future living from day to day, week to week unable to plan for anything other than the short term.
It has been a time of uncertainty about the future living from day to day, week to week unable to plan for anything other than the short term.
Those with lupus frequently say they don't know from day to day, sometimes hour to hour, how they will feel or what they will be capable of doing.
Of course it waxes and wanes literally from hour to hour.
His actual policies fluctuate from hour to hour and have the wonderful capacity to be whatever would suit each individual voter best.
The choice, he said, would change from hour to hour, from minute to minute, so don't consider it definitive.
How many shows do we see Gloria commenting on from day to day, actually from hour to hour?
I have learned to exist with the pain and panics and live from hour to hour.
It is loyalty to the cause, however it is defined and however it changes in principle from day to day, that matters.
But one of the problems with this town's that there's very little consistency from day to day, month to month, year to year.
from on - Starting at the specified point in time and continuing into the future.
Starting at the specified point in time and continuing into the future.
from now on recipients will get their fellowships on time
More example sentences - they were friends from that day on
they were friends from that day on - The Finance Ministry made sure the prime minister shut his mouth from then on.
The Finance Ministry made sure the prime minister shut his mouth from then on.
I also had too many versions of one song in my head which also gave me trouble, but eventually I relaxed and things went much better from then on.
We resupplied our groceries and from then on provided our own kitchen staff and cooked our own meals.
Williams started hitting some outrageous winners from then on.
Oil supplies would tighten and prices would rise from then on, experts predicted.
What it did to me though is it made me allergic to shellfish from then on since my body used all its anti-bodies to fight the poison.
At the age of sixteen, his parents sent him for further schooling in the United Sates - a country where he lived from then on.
The list of weekly winners will be appearing in these columns from now on.
Not that I ever said anything of a personal nature anyway, but I think I'm going to be saying even less from now on.
His paintings from then on portrayed gigantic, sensuous and cruel women, with pouting lips, masses of wavy hair and columnar necks.
Origin - Old English fram, from, of Germanic origin; related to Old Norse fr (see fro).
Old English fram, from, of Germanic origin; related to Old Norse fr (see fro).
Are You Learning English? Here Are Our Top English Tips
A glass pane is a transparent block that can be used as a more efficient alternative to glass blocks.
Glass panes can be obtained using a tool enchanted with Silk Touch. If one is broken without a Silk Touch enchantment, it drops nothing.
Orange and red stained glass panes generate in savanna village temples. Yellow stained glass panes generate in plains and savanna village temples. Brown stained glass panes generate in abandoned villages. White stained glass panes generate in plains village temples.
Glass panes are more efficient to use than glass blocks, as six glass blocks can be crafted into sixteen glass panes, yielding 223 panes per block. Windows built using glass panes can be up to 267% (223 times) larger in area than windows built with regular glass blocks.
A single space between two glass panes results in a 21 hole, which spiders can pass through.
If placed without anything on the sides, they appear as a thin vertical shape, 22 pixels in size; but when other blocks occupy adjacent spaces, it becomes flat or turns into a or or shape depending on the items surrounding it. The collision box is identical to the shape of the pane. Therefore, two glass panes placed with one empty space in between forms a gap that is two blocks wide.
Glass panes are never oriented horizontally. Horizontal glass surfaces must be made from glass blocks.
Glass panes can be used in cartography tables to lock maps, which makes them unable to be filled again when exploring.
Apprentice-level cartographer villagers buy 11 glass panes for an emerald as part of their trades.
Glass panes can now be recovered by harvesting them with a Silk Touch-enchanted pickaxe.
The model of glass panes is now always prismatic, as opposed to the prior thick-rimmed thin panes from earlier.
The textures of stained glass panes have now been smoothed, their transparency has now been increased and their back side is now no longer showing, like in regular glass panes.
Glass panes without any connecting blocks are now 22 pixels in footprint (like a , rather than a +).
Glass panes and stained glass panes can now be used to craft hardened glass panes.
Glass panes can now be recovered by harvesting them with a Silk Touch enchanted pickaxe.
Glass panes and stained glass panes now connect to the solid back side of stairs.
Issues relating to "Glass Pane" are maintained on the bug tracker. Report issues there.
Due to its flat appearance in the inventory slot and the inventory being colored light gray, light gray stained glass panes almost appear invisible;[Java Edition only] this is intentional.[2]
Panes are thin, so it is possible for players or mobs to fit in a 121 space, which makes them useful for creating trophy displays, like this Creeper here.
Water does not flow through the holes in the panes, but the player can fit inside them.
Tools - In other languages
In other languages - This page was last edited on 11 May 2021, at 19:12.
This page was last edited on 11 May 2021, at 19:12.
Content is available under CC BY-NC-SA 3.0 unless otherwise noted. Game content and materials are trademarks and copyrights of their respective publisher and its licensors. All rights reserved. This site is a part of Fandom, Inc. and is not affiliated with the game publisher.
Types of column - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Classical stone columns
2 Classical stone columns - 3 Steel columns
3 Steel columns - 4 Slenderness ratio
4 Slenderness ratio - 5 Shape
5 Shape - 6 Reinforced concrete columns
6 Reinforced concrete columns - 7 Other types of column
7 Other types of column - 7.1 Stone column
7.1 Stone column - 7.2 Pilotis
7.2 Pilotis - 7.3 Piers
7.3 Piers - 7.4 Posts
7.4 Posts - 7.5 Knotted
7.5 Knotted - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - Introduction
Introduction - A column is a vertical structural member intended to transfer a compressive load. For example, a column might transfer loads from a ceiling, floor or roof slab or from a beam, to a floor or foundations.
A column is a vertical structural member intended to transfer a compressive load. For example, a column might transfer loads from a ceiling, floor or roof slab or from a beam, to a floor or foundations.
Columns are typically constructed from materials such as stone, brick, block, concrete, timber, steel, and so on, which have good compressive strength.
Glazing (window) - Glazing, which derives from the Middle English for 'glass', is a part of a wall or window, made of glass.[1][2] Glazing also describes the work done by a professional "glazier". Glazing is also less commonly used to describe the insertion of ophthalmic lenses into an eyeglass frame.[3]
Glazing, which derives from the Middle English for 'glass', is a part of a wall or window, made of glass.[1][2] Glazing also describes the work done by a professional "glazier". Glazing is also less commonly used to describe the insertion of ophthalmic lenses into an eyeglass frame.[3]
Common types of glazing that are used in architectural applications include clear and tinted float glass, tempered glass, and laminated glass as well as a variety of coated glasses, all of which can be glazed singly or as double, or even triple, glazing units. Ordinary clear glass has a slight green tinge[4] but special colorless glasses are offered by several manufacturers.[5]
Glazing can be mounted on the surface of a window sash or door stile, usually made of wood, aluminium or PVC. The glass is fixed into a rabbet (rebate) in the frame in a number of ways including triangular glazing points, putty, etc. Toughened and laminated glass can be glazed by bolting panes directly to a metal framework by bolts passing through drilled holes.
Glazing is commonly used in low temperature solar thermal collectors because it helps retain the collected heat.
This glass engineering or glass science related article is a stub. You can help Wikipedia by expanding it.
Beam Analysis Properties - Help
Help - Modify the analytical properties of the beam to accommodate structural analysis tools and procedures.
Modify the analytical properties of the beam to accommodate structural analysis tools and procedures.
To change structural analytical properties, select the element. In the Properties palette, select the element specific analytical properties from the Properties filter.
Name - Description
Description - Analytical Model
Analytical Model - Analyze as
Analyze as - Used by external analysis applications to determine whether beam conditions contribute to Gravity or Lateral analysis.
Used by external analysis applications to determine whether beam conditions contribute to Gravity or Lateral analysis.
Analytical Links - Either Yes, No, or From Column. A frame element that can be set to fully rigid or released in global directions. When Analytical Links are enabled, an additional analytical segment is engaged in the model between the end of the analytical model of a beam and the analytical model of a column. From Column defines the analytical link of the beam to that of its connected column.
Either Yes, No, or From Column. A frame element that can be set to fully rigid or released in global directions. When Analytical Links are enabled, an additional analytical segment is engaged in the model between the end of the analytical model of a beam and the analytical model of a column. From Column defines the analytical link of the beam to that of its connected column.
Applies to curved beams only. Select to create segment based on both the values for Maximum discretized offset and Use hard-points. See Segmented Analytical Model Parameters.
Maximum discretized offset - Applies to curved beams only. Limits the distance between a smooth curve and a line segment when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Applies to curved beams only. Limits the distance between a smooth curve and a line segment when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Use hard-points - Applies to curved beams only. Forces the segmented analytical model to have nodal points at the ends of the members attached to the curved beam when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Applies to curved beams only. Forces the segmented analytical model to have nodal points at the ends of the members attached to the curved beam when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Analytical Properties - Family Type
Family Type - The family type of the element.
The family type of the element. - Physical Material Asset
Physical Material Asset - The name of a physical asset assigned to the beam material (read-only).
The name of a physical asset assigned to the beam material (read-only).
Length - The length of the analytical model.
The length of the analytical model. - Cross-Section Rotation
Cross-Section Rotation - Displays the cross-section rotation of analytical members. The angle of rotation is measured from the work plane of the member and the direction of the center reference plane.
Displays the cross-section rotation of analytical members. The angle of rotation is measured from the work plane of the member and the direction of the center reference plane.
Analytical Alignment - Start Alignment Method
Start Alignment Method - Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam start position are automatically justified or have a defined projection.
Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam start position are automatically justified or have a defined projection.
Start y Projection - Either Location Line, Left of Element, Center of Element, Right of Element, , or . Available when Start Alignment Method is specified as Projection.
Either Location Line, Left of Element, Center of Element, Right of Element,
Specifies the horizontal location of the analytical model at the start of the beam.
Start z Projection - Either Location Line, Top of Element, Center of Element, Bottom of Element, , , or . Available when Start Alignment Method is specified as Projection.
Either Location Line, Top of Element, Center of Element, Bottom of Element,
Specifies the vertical location of the analytical model at the start of the beam.
End Alignment Method - Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam end position are automatically justified or have a defined projection.
Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam end position are automatically justified or have a defined projection.
End y Projection - Either Location Line, Left of Element, Center of Element, Right of Element, , or . Available when End Alignment Method is specified as Projection.
Either Location Line, Left of Element, Center of Element, Right of Element,
Specifies the horizontal location of the analytical model at the end of the beam.
End z Projection - Either Location Line, Top of Element, Center of Element, Bottom of Element, , , or . Available when End Alignment Method is specified as Projection.
Either Location Line, Top of Element, Center of Element, Bottom of Element,
Specifies the vertical location of the analytical model at the end of the beam.
Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Start Fx - The translational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
Start Fy - The translational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
Start Fz - The translational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
Start Mx - The rotational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
Start My - The rotational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
Start Mz - The rotational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
End Release - Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
End Fx - The translational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
End Fy - The translational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
End Fz - The translational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
End Mx - The rotational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
End My - The rotational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
End Mz - The rotational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
Member Forces - Specifies the internal forces at the start and end of the analytical beams and braces. This data communicates load information for both documentation and connection fabrication. Click Edit to enter user-defined force and moment values.
Specifies the internal forces at the start and end of the analytical beams and braces. This data communicates load information for both documentation and connection fabrication. Click Edit to enter user-defined force and moment values.
Identity Data - Member Number
Member Number - An identifier created for the analytical member. This value should be unique across Analytical Beams, Analytical Braces and Analytical Columns in a project. Revit warns you if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Review Warning Messages.
An identifier created for the analytical member. This value should be unique across Analytical Beams, Analytical Braces and Analytical Columns in a project. Revit warns you if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Review Warning Messages.
Comments - User comments.
User comments. - Phasing
Phasing - Phase Created
Phase Created - Indicates in which phase the beam was created. See Project Phasing.
Indicates in which phase the beam was created. See Project Phasing.
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About the Structural Usage of Beams - Help
Help - The Structural Usage property of a beam is typically automatically assigned based on the structural elements that support the beam. However, structural usage can be changed before or after the beam is placed.
The Structural Usage property of a beam is typically automatically assigned based on the structural elements that support the beam. However, structural usage can be changed before or after the beam is placed.
The following table lists the default automatic Structural Usage setting for beams, based on which elements are being connected:
Key. HB: Horizontal Bracing; G: Girder; J: Joist; P: Purlin; and O: Other.
Beams and their structural properties also have the following characteristics:
The default Structural Usage setting can be changed using the Properties palette.
Beams can be attached to any other structural element, including structural walls, however they will not join to non-bearing walls.
The structural usage parameter can be included in a structural framing schedule, allowing quantity calculation of girders, joists, purlins, and horizontal bracing.
The structural usage parameter value determines the line style of the beam in a coarse-scale view. Use the Object Styles dialog to change the default styles of structural usage.
Beams also have a structural usage as the chords of a structural truss.
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Run Component Instance Properties - Help
Help - Specifies the position of the run relative to the Up-direction path used to create the run. Options include:
Specifies the position of the run relative to the Up-direction path used to create the run. Options include:
Run: Center (3) - Run: Right (4)
Run: Right (4) - Specifies the base height of the run relative to the base elevation of the stair.
Specifies the base height of the run relative to the base elevation of the stair.
Relative Top Height - Specifies the top height of the run relative to the base elevation of the stair.
Specifies the top height of the run relative to the base elevation of the stair.
Run Height - Displays the calculated height of the run. (Read only)
Displays the calculated height of the run. (Read only)
Construction - Extend Below Base
Extend Below Base - Specifies a distance to extend the run below the base level of the stair. This is useful in cases where the run attaches to the face of a floor opening rather than resting on the surface of the floor. To extend the run below the floor, enter a negative number.
Specifies a distance to extend the run below the base level of the stair. This is useful in cases where the run attaches to the face of a floor opening rather than resting on the surface of the floor. To extend the run below the floor, enter a negative number.
Extend Below Base = 0 - Extend Below Base = 0' 5"
Extend Below Base = 0' 5" - Extend Below Base = -0' 2"
Extend Below Base = -0' 2"
Select to add a riser to the beginning of the run.
Clear to remove the beginning riser and position the adjacent tread at the base elevation. Clearing this option will change the number of risers in the run. You will need to manually add a riser to maintain the original height.
Note: If Begin with Riser is selected, then a notch connection method cannot be used for the run end.
End with Riser - Select to add a riser to the end of the run. Clear to remove the ending riser. Clearing this option will change the number of risers in the run. You will need to manually add or remove risers to maintain the original height.
Select to add a riser to the end of the run. Clear to remove the ending riser. Clearing this option will change the number of risers in the run. You will need to manually add or remove risers to maintain the original height.
Note: If End with Riser is selected, then a notch connection method cannot be used for the run end.
Structural - Structural
Structural - Indicates that the element has an analytical model.
Indicates that the element has an analytical model.
Winders - Note: Winder properties are valid for L-shape and U-shape winder runs.
Note: Winder properties are valid for L-shape and U-shape winder runs.
Winder Style - Specifies the calculation for the winder run steps. Choose from:
Specifies the calculation for the winder run steps. Choose from:
Balanced - Symmetrical layout style. (Default)
Single-point - Asymmetrical layout style. Winder style is calculated from a single center point.
Specifies the distance of the inside walk path from the interior boundary of the winder run. This distance specifies where to measure the Minimum Width on Inside Walk Line. (Refer to 1 in Winder Properties.)
Minimum Width on Inside Walk Line - Specifies the minimum tread depth measured at the Inside Walk Line Offset. (Read only) (Refer to 2 in Winder Properties.)
Specifies the minimum tread depth measured at the Inside Walk Line Offset. (Read only) (Refer to 2 in Winder Properties.)
Minimum Width on Inside Boundary - Specifies the minimum tread depth at the interior corners of a winder run. (Refer to 3 in Winder Properties.)
Specifies the minimum tread depth at the interior corners of a winder run. (Refer to 3 in Winder Properties.)
Fillet on Corner - Select to apply fillet geometry to the interior corner of the L-shape winder run or to both interior corners of a U-shape winder run.
Select to apply fillet geometry to the interior corner of the L-shape winder run or to both interior corners of a U-shape winder run.
Fillet Radius - Specifies the radius to be used for the fillet geometry on the interior corners of a winder run. (Refer to 4 in Winder Properties.)
Specifies the radius to be used for the fillet geometry on the interior corners of a winder run. (Refer to 4 in Winder Properties.)
Parallel Treads at Start - Specifies an optional number of uniform steps to add to the beginning of the winder run. (Refer to 5 in Winder Properties.)
Specifies an optional number of uniform steps to add to the beginning of the winder run. (Refer to 5 in Winder Properties.)
Parallel Treads at End - Specifies an optional number of uniform steps to add to the end of the winder run. (Refer to 6 in Winder Properties.)
Specifies an optional number of uniform steps to add to the end of the winder run. (Refer to 6 in Winder Properties.)
Dimensions - Actual Run Width
Actual Run Width - Specifies the value of the tread width excluding the width of independent side supports.
Specifies the value of the tread width excluding the width of independent side supports.
Actual Riser Height - Specifies the value of the riser height. (Read only)
Specifies the value of the riser height. (Read only)
Actual Tread Depth - Specifies the value of the tread depth as measured along the stair path. This is a read-only value.
Specifies the value of the tread depth as measured along the stair path. This is a read-only value.
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Door Type Properties - Help
Help - Modify door type properties to change its construction type, function, materials, dimensions, and more.
Modify door type properties to change its construction type, function, materials, dimensions, and more.
To change type properties, select an element and click Modify tabProperties panel (Type Properties). Changes to type properties apply to all instances in the project.
Name - Description
Description - Construction
Construction - Wall Closure
Wall Closure - The layer wrapping around the door. It overrides any settings in the host.
The layer wrapping around the door. It overrides any settings in the host.
Construction Type - The type of construction for the door.
The type of construction for the door. - Function
Function - Indicates whether a door is interior (default value) or exterior. Function is used in scheduling and to create filters to simplify a model when exporting.
Indicates whether a door is interior (default value) or exterior. Function is used in scheduling and to create filters to simplify a model when exporting.
Materials and Finishes - Door Material
Door Material - The material for the door (for example, metal or wood)
The material for the door (for example, metal or wood)
Add or edit the door keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
The name of the model type of the door.
Manufacturer - The name of the door manufacturer.
The name of the door manufacturer. - Description of the assembly based on the assembly code selection.
Description of the assembly based on the assembly code selection.
Assembly Code - Uniformat assembly code selected from hierarchical list.
Uniformat assembly code selected from hierarchical list. - Type Mark
Type Mark - A value to designate the particular door type. This value must be unique for each door type in a project. Revit warns you if the number is already used, but allows you to continue using it. (You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.)
A value to designate the particular door type. This value must be unique for each door type in a project. Revit warns you if the number is already used, but allows you to continue using it. (You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.)
The fire rating of the door. - Cost
Cost - The cost of the door.
The cost of the door. - The number from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
The number from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
OmniClass Title - The name from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
The name from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
IFC Parameters - Operation
Operation - The operation of the door, as defined by the current IFC description (for example, single_swing_left or double_door_double_swing). These values are case-insensitive, and underscores are optional. (SINGLE_SWING_LEFT and SingleSwingLeft are the same.)
The operation of the door, as defined by the current IFC description (for example, single_swing_left or double_door_double_swing). These values are case-insensitive, and underscores are optional. (SINGLE_SWING_LEFT and SingleSwingLeft are the same.)
Analytical Properties - Analytic Construction
Analytic Construction - Heat Transfer Coefficient (U)
Heat Transfer Coefficient (U) - Used in calculating the heat transfer, typically by convection or phase change between a fluid and a solid.
Used in calculating the heat transfer, typically by convection or phase change between a fluid and a solid.
Thermal Resistance (R) - A measure of a temperature difference, by which an object, or material, resist a heat flow (heat per time unit or thermal resistance.
A measure of a temperature difference, by which an object, or material, resist a heat flow (heat per time unit or thermal resistance.
Solar Heat Gain Coefficient - The fraction of incident solar radiation admitted through a window, both directly transmitted and absorbed and subsequently released inward.
The fraction of incident solar radiation admitted through a window, both directly transmitted and absorbed and subsequently released inward.
Visual Light Transmittance - The amount of visible light that passes through a glazing system, expressed as a percent.
The amount of visible light that passes through a glazing system, expressed as a percent.
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About Element Behavior in Revit - Help
Help - Revit uses 3 types of elements in projects: model elements, datum elements, and view-specific elements. Elements in Revit are also referred to as families. The family contains the geometric definition of the element and the parameters used by the element. Each instance of an element is defined and controlled by the family.
Revit uses 3 types of elements in projects: model elements, datum elements, and view-specific elements. Elements in Revit are also referred to as families. The family contains the geometric definition of the element and the parameters used by the element. Each instance of an element is defined and controlled by the family.
Model elements represent the actual 3D geometry of the building. They display in relevant views of the model.
Examples: - Walls, windows, doors, and roofs
Walls, windows, doors, and roofs - Structural walls, slabs, and ramps
Structural walls, slabs, and ramps - Sinks, boilers, ducts, sprinklers, and electrical panels
Sinks, boilers, ducts, sprinklers, and electrical panels
Datum elements help to define project context. For example, grids, levels, and reference planes are datum elements.
View-specific elements display only in the views in which they are placed. They help to describe or document the model. For example, dimensions are view-specific elements.
Elements for Revit - There are 2 types of model elements:
There are 2 types of model elements: - Hosts (or host elements) are generally built in place at the construction site.
Hosts (or host elements) are generally built in place at the construction site.
Examples: - Windows, doors, and cabinets
Windows, doors, and cabinets - Beams, braces, and structural columns
Beams, braces, and structural columns - Sinks, boilers, ducts, sprinklers, and electrical panels
Sinks, boilers, ducts, sprinklers, and electrical panels
There are 2 types of view-specific elements: - Annotation elements are 2D components that document the model and maintain scale on paper. For example, dimensions, tags, and keynotes are annotation elements.
Annotation elements are 2D components that document the model and maintain scale on paper. For example, dimensions, tags, and keynotes are annotation elements.
Details are 2D items that provide details about the building model in a particular view. Examples include detail lines, filled regions, and 2D detail components.
This implementation provides flexibility for designers. Revit elements are designed to be created and modified by you directly; programming is not required. If you can draw, you can define new parametric elements in Revit.
In Revit, the elements determine their behavior largely from their context in the building. The context is determined by how you draw the component and the constraint relationships that are established with other components. Often, you do nothing to establish these relationships; they are implied by what you do and how you draw. In other cases, you can explicitly control them, by locking a dimension or aligning 2 walls, for example.
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About Layer Wrapping - Help
Help - Compound wall layers can wrap at inserts and at the end caps of the wall.
Compound wall layers can wrap at inserts and at the end caps of the wall.
Select the Wraps checkbox in the Edit Assembly dialog to specify the layer of the compound wall to wrap at the ends of the wall, or when an insert (e.g., a door or window) is placed in the wall. The Wrapping at Ends and Wrapping at Inserts parameters must be specified in the type properties of the wall for individual layers to wrap.
Note: Wrapping is not enabled for roof and floor compound elements.
Wrapping at Ends - End conditions of walls can be set to Interior or Exterior to control which side of the wall the materials will wrap to. If you do not want the layers of the wall to wrap, set end conditions to None.
End conditions of walls can be set to Interior or Exterior to control which side of the wall the materials will wrap to. If you do not want the layers of the wall to wrap, set end conditions to None.
Compound wall with no end-cap wrapping - Exterior wrapping at a wall's end caps
Exterior wrapping at a wall's end caps - Interior wrapping at the end caps
Interior wrapping at the end caps - Wrapping at Inserts
Wrapping at Inserts - Wrapping at inserts can be set to wrap material on the interior, exterior, both, or none. The position of the wrap at an insert is controlled by reference planes defined as "Wall Closure" in the insert family.
Wrapping at inserts can be set to wrap material on the interior, exterior, both, or none. The position of the wrap at an insert is controlled by reference planes defined as "Wall Closure" in the insert family.
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Run Component Type Properties - Help
Help - Modify type properties to change the construction, materials, treads, and risers for a stair run family.
Modify type properties to change the construction, materials, treads, and risers for a stair run family.
Run Types - Run component types are available from 2 predefined system families:
Run component types are available from 2 predefined system families:
Monolithic Run: - Non-Monolithic Run:
Non-Monolithic Run: - Type Properties
Type Properties - To change type properties, select an element and click Modify tabProperties panel (Type Properties). Changes to type properties apply to all instances in the project.
To change type properties, select an element and click Modify tabProperties panel (Type Properties). Changes to type properties apply to all instances in the project.
Name - Description
Description - Construction
Construction - Underside Surface
Underside Surface - Specifies the style of the underside surface of the run:
Specifies the style of the underside surface of the run:
Smooth - Stepped
Stepped - Structural Depth
Structural Depth - If the Underside Surface is smooth, the Structural Depth is the dimension in the following image:
If the Underside Surface is smooth, the Structural Depth is the dimension in the following image:
If the underside Surface is stepped, the Structural Depth is the dimension in the following image:
Materials and Finishes - Monolithic Material
Monolithic Material - Click the value and then click the browse button to open the Materials dialog. See Materials.
Click the value and then click the browse button to open the Materials dialog. See Materials.
Specifies the outline shape for the edge of the tread. The default is rectangular, though a profile could be used to create wedge or angled steps.
Nosing Length - Specifies the amount of the tread depth that overhangs the next tread.
Specifies the amount of the tread depth that overhangs the next tread.
Nosing Profile - The profile for a sweep added to the front or sides of the tread, depending on the specification for the Apply Nosing Profile property described below.
The profile for a sweep added to the front or sides of the tread, depending on the specification for the Apply Nosing Profile property described below.
See Creating a Sweep. Revit has predefined profiles to use for the sweep.
Apply Nosing Profile - Specifies the nosing edges to which the nosing profile is applied.
Specifies the nosing edges to which the nosing profile is applied.
Risers - Select for slanted risers, or clear for straight risers.
Select for slanted risers, or clear for straight risers.
Riser Thickness - Specifies the thickness of the risers.
Specifies the thickness of the risers. - Riser Profile
Riser Profile - Specifies the outline shape for the edge of the riser. The default is Rectangular.
Specifies the outline shape for the edge of the riser. The default is Rectangular.
Riser to Tread Connection - Specifies the connection of the riser and tread in relation to each other.
Specifies the connection of the riser and tread in relation to each other.
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Stair by Sketch Type Properties - Help
Help - Modify type properties to change the calculation rules, stringers, risers, treads, and more for a stair by sketch family.
Modify type properties to change the calculation rules, stringers, risers, treads, and more for a stair by sketch family.
To change type properties, select an element and click Modify tabProperties panel (Type Properties). Changes to type properties apply to all instances in the project.
Extends stringers below the base level of the stair. This is useful for cases where the stringer attaches to the face of a floor opening rather than resting on the surface of a floor. To extend the stringer below the floor, enter a negative number.
Monolithic Stairs - Specifies that the stairs are to be made of one material.
Specifies that the stairs are to be made of one material.
Landing Overlap - Enabled when stairs are set to monolithic. When a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped. If it is stepped, this parameter controls the distance between the riser face and the vertical face of the corresponding step on the underside.
Enabled when stairs are set to monolithic. When a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped. If it is stepped, this parameter controls the distance between the riser face and the vertical face of the corresponding step on the underside.
Underside of Winder - Enabled when stairs are set to monolithic. If a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped.
Enabled when stairs are set to monolithic. If a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped.
Function - Indicates whether the stairs are interior (default value) or exterior. Function is used in scheduling and to create filters to simplify a model when exporting.
Indicates whether the stairs are interior (default value) or exterior. Function is used in scheduling and to create filters to simplify a model when exporting.
Graphics - Break Symbol in Plan
Break Symbol in Plan - Specifies whether the cut line of the stairs in plan view has a break line.
Specifies whether the cut line of the stairs in plan view has a break line.
Text Size - Changes the size of the UP-DN symbol in a plan view.
Changes the size of the UP-DN symbol in a plan view.
Text Font - Sets the font of the UP-DN symbol.
Sets the font of the UP-DN symbol. - Materials and Finishes
Materials and Finishes - Tread Material
Tread Material - Click the button to open the Material Browser. See Materials for more information on creating a material.
Click the button to open the Material Browser. See Materials for more information on creating a material.
Sets the initial value for the Actual Tread Depth instance parameter. If the Actual Tread Depth value exceeds this value, Revit issues a warning.
Tread Thickness - Sets the thickness of the tread.
Sets the thickness of the tread. - Nosing Length
Nosing Length - Specifies the amount of the tread depth that overhangs the next tread.
Specifies the amount of the tread depth that overhangs the next tread.
Specifies 1-sided, 2-sided, or 3-sided tread nosing.
Risers - Maximum Riser Height
Maximum Riser Height - Sets the maximum height of each riser on the staircase.
Sets the maximum height of each riser on the staircase.
Begin with Riser - If selected, Revit adds a riser to the beginning of the stairs. If you clear the check box, Revit removes the beginning riser. Note that you may receive a warning about the actual number of risers exceeding the desired number of risers if you clear this check box. To resolve this, either select End with Riser, or change the desired number of risers.
If selected, Revit adds a riser to the beginning of the stairs. If you clear the check box, Revit removes the beginning riser. Note that you may receive a warning about the actual number of risers exceeding the desired number of risers if you clear this check box. To resolve this, either select End with Riser, or change the desired number of risers.
End with Riser - If selected, Revit adds a riser to the end of the stairs. If you clear the check box, Revit removes the end riser.
If selected, Revit adds a riser to the end of the stairs. If you clear the check box, Revit removes the end riser.
Creates straight or slanted risers, or no riser.
Riser Thickness - Sets the thickness of the riser.
Sets the thickness of the riser. - Switches the connection of the riser and tread in relation to each other. The riser can extend behind the tread, or the tread can extend under the riser.
Switches the connection of the riser and tread in relation to each other. The riser can extend behind the tread, or the tread can extend under the riser.
Stringers - Trim Stringers at Top
Trim Stringers at Top - Trim Stringers at Top affects the top end of stringers on a stair run. If you select Do Not Trim, the stringer is cut with a single vertical cut resulting in a point at the top. If you select Match Level, the stringer is cut horizontally, making the top of the stringer flush with the top level. If you select Match Landing Stringer, a horizontal cut is made at the same height as the stringer top on landings. To see the effects of this parameter clearly, you may want to clear the check box for End with Riser.
Trim Stringers at Top affects the top end of stringers on a stair run. If you select Do Not Trim, the stringer is cut with a single vertical cut resulting in a point at the top. If you select Match Level, the stringer is cut horizontally, making the top of the stringer flush with the top level. If you select Match Landing Stringer, a horizontal cut is made at the same height as the stringer top on landings. To see the effects of this parameter clearly, you may want to clear the check box for End with Riser.
Right Stringer - Sets the type of stringer for the right side of the stairs. None means there is no stringer. A closed stringer encases the treads and risers. An open stringer exposes the treads and risers.
Sets the type of stringer for the right side of the stairs. None means there is no stringer. A closed stringer encases the treads and risers. An open stringer exposes the treads and risers.
Left Stringer - See description for Right Stringer.
See description for Right Stringer. - Middle Stringers
Middle Stringers - Sets the number of stringers that appear underneath the stairs between the left and right of the stairs.
Sets the number of stringers that appear underneath the stairs between the left and right of the stairs.
Sets the thickness of the stringers. - Stringer Height
Stringer Height - Sets the height of the stringers.
Sets the height of the stringers. - Enabled when the stairs have an open stringer. Moves an open stringer from side to side. For example, if you offset an open right stringer, it moves toward the left stringer.
Enabled when the stairs have an open stringer. Moves an open stringer from side to side. For example, if you offset an open right stringer, it moves toward the left stringer.
Stringer Carriage Height - Controls the relationship between the side stringers and treads. If you increase the number, the stringer moves down from the treads. Treads do not move. Railings do not change height relative to treads, but the balusters extend down to meet the stringer top. This height is measured from the tread end (lower corner) to the bottom side of the stringer, perpendicular to the stringer.
Controls the relationship between the side stringers and treads. If you increase the number, the stringer moves down from the treads. Treads do not move. Railings do not change height relative to treads, but the balusters extend down to meet the stringer top. This height is measured from the tread end (lower corner) to the bottom side of the stringer, perpendicular to the stringer.
Landing Carriage Height - Allows stringers to have a different height relationship to landings than they do to sloped runs. For example, it lowers a horizontal stringer toward a landing on u-shaped stairs.
Allows stringers to have a different height relationship to landings than they do to sloped runs. For example, it lowers a horizontal stringer toward a landing on u-shaped stairs.
Identity Data - Type Mark
Type Mark - A value to designate the particular stairs. Useful if you need to identify more than one set of staircases. This value must be unique for each stairway in a project. Revit warns you if the number is already used but allows you to continue using it. (You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.)
A value to designate the particular stairs. Useful if you need to identify more than one set of staircases. This value must be unique for each stairway in a project. Revit warns you if the number is already used but allows you to continue using it. (You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.)
Keynote - Adds or edits the stairs keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
Adds or edits the stairs keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
Model - The model type for the stairs. May not be applicable.
The model type for the stairs. May not be applicable.
Manufacturer - Manufacturer for the stair materials. May not be applicable.
Manufacturer for the stair materials. May not be applicable.
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Video: Layer Wrapping at Wall Ends - Help
Help - Define how each layer of a compound wall will finish at the end.
Define how each layer of a compound wall will finish at the end.
This video demonstrates the following: - Setting view properties so wrapping can be seen.
Setting view properties so wrapping can be seen.
Setting wall layers to wrap form the exterior.
Change the wrapping behavior for specific layers. - Note: This video was recorded using Revit 2020. When using a newer software release, you may notice differences in functionality and user interface.
Note: This video was recorded using Revit 2020. When using a newer software release, you may notice differences in functionality and user interface.
Transcript - The Wrapping at Ends parameter in a wall type is the primary control used to determine the way material layers wrap at the ends of walls. There are other settings in the wall structure that can affect the wrapping behavior.
The Wrapping at Ends parameter in a wall type is the primary control used to determine the way material layers wrap at the ends of walls. There are other settings in the wall structure that can affect the wrapping behavior.
To see how changes affect wrapping, set the view style to Shaded, then change the scale. On the View tab, turn on Thin Lines. Currently, the wall has a number of layers, but none are set to wrap.
To wrap the layers at the ends, select the wall and click Edit Type on the Properties palette. The wrapping at the ends can be set to wrap material from the exterior to the interior, or from the interior to the exterior. In this example, we want the brick to wrap around the ends of the wall, so we choose Exterior and click Apply.
You can see that the brick, air space, and the insulation were all wrapped. In this wall, only the brick should wrap. Edit the structure of the wall. In the Edit Assembly dialog, clear the check mark under Wraps heading for the air and insulation layers of the wall.
The layer function and position can also affect the wrapping behavior. For example, if the function of the gyp. board is changed to match the function of the brick, the brick will wrap to the gyp. board. If the furring and the gypsum board are moved into the core, the brick will wrap the entire wall end.
Modify wall wrapping to illustrate different conditions in your model.
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Using Justification Parameters - Help
Help - The justification parameters reposition the geometry of the element in relation to the location line. You can justify a beam or brace in both y and z directions.
The justification parameters reposition the geometry of the element in relation to the location line. You can justify a beam or brace in both y and z directions.
To justify a beam or brace - Select either a beam or brace. The location line of the element becomes active.
Select either a beam or brace. The location line of the element becomes active.
On the Properties palette under Geometric Position you can adjust the following justification parameters:
For y Justification, select Origin, Left, Center, or Right.
This repositioning is dependent on how the element was drawn and based on the directions of axes of the coordinate system of the element. The following beam was drawn from the top (start point) to bottom (end point).
y Justification Left - y Justification Right
y Justification Right - For z Justification, select Origin, Top, Center, or Bottom.
For z Justification, select Origin, Top, Center, or Bottom.
Tip: If you want to justify the start and the end of a beam or brace independently, select Independent for the yz Justification parameter. The justification parameters are then available for either end of a beam or brace.
The physical model of the beam is moved in reference to its location line.
The blue dot in the following examples represents the location line in an elevation view of the beam.
y Justification with the z Justification at center.
Center/Origin - Left
Left - Right
Right - z Justification with the y Justification at center.
z Justification with the y Justification at center.
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Analytical Model - Essential Skill - Help
Help - Learn how to work with the analytical model for structural analysis and design.
Learn how to work with the analytical model for structural analysis and design.
The analytical model, created automatically by Revit as you build the physical model, is used to perform the structural analysis and design. You export the analytical model to the analysis and design software.
Terms and Concepts - Term/Concept
Term/Concept - Definition
Definition - Analytical Model
Analytical Model - A representation of the structural physical model consisting of analytical elements, geometry, material properties, and loads. It is created automatically while creating the physical model. You export the analytical model to the structural analysis and design software.
A representation of the structural physical model consisting of analytical elements, geometry, material properties, and loads. It is created automatically while creating the physical model. You export the analytical model to the structural analysis and design software.
Analytical Element Properties - Instance parameters of an analytical element. They also display some properties directly from the physical element related to the selected analytical element.
Instance parameters of an analytical element. They also display some properties directly from the physical element related to the selected analytical element.
Analytical Edit Mode - An environment that allows you to adjust analytical elements by direct manipulation. When you enter this mode, the ribbon displays the tools needed to make adjustments to a selected analytical element.
An environment that allows you to adjust analytical elements by direct manipulation. When you enter this mode, the ribbon displays the tools needed to make adjustments to a selected analytical element.
Analytical Alignment Properties - The instance parameters that you can use to adjust the location of an analytical element. If the Alignment Method is set to Auto-Detect, the analytical model is adjusted based on the tolerance settings. If the Alignment Method is set to Projection, you can select the location of the analytical model from the available projection options.
The instance parameters that you can use to adjust the location of an analytical element. If the Alignment Method is set to Auto-Detect, the analytical model is adjusted based on the tolerance settings. If the Alignment Method is set to Projection, you can select the location of the analytical model from the available projection options.
Auto-Detect - The mechanism ensuring consistency of the analytical model; it connects analytical elements based on their proximity. You can specify Auto-Detect tolerance settings.
The mechanism ensuring consistency of the analytical model; it connects analytical elements based on their proximity. You can specify Auto-Detect tolerance settings.
Structural Settings - The dialog where you can add load cases and load combinations, and define settings for boundary conditions (supports) and analytical model settings.
The dialog where you can add load cases and load combinations, and define settings for boundary conditions (supports) and analytical model settings.
Analytical Model Settings - The tab in the Structural Settings dialog where you can define the tolerances for Auto-Detect and Analytical/Physical Model Consistency Check, and a list of Consistency Check criteria.
The tab in the Structural Settings dialog where you can define the tolerances for Auto-Detect and Analytical/Physical Model Consistency Check, and a list of Consistency Check criteria.
Video - This video demonstrates the following:
This video demonstrates the following: - Display the analytical model of a structure.
Display the analytical model of a structure. - Display analytical element properties.
Display analytical element properties. - Use the tools for adjusting the analytical model.
Use the tools for adjusting the analytical model.
Transcript - This view represents the physical model of a building. The analytical model is a representation of the building required for structural analysis and design. To see the analytical model in a view, click the Show Analytical Model tool on the View Control Bar.
This view represents the physical model of a building. The analytical model is a representation of the building required for structural analysis and design. To see the analytical model in a view, click the Show Analytical Model tool on the View Control Bar.
To work on the analytical model, open the Analytical Model view from the Project Browser. When you select an analytical element, instance properties display on the Properties palette. Use the drop-down list to display physical properties for the selected element.
The Analyze tab contains tools for defining loads and boundary conditions, and adjusting the analytical model. Click the dialog launcher to open the Structural Settings dialog. Use the Analytical Model Settings tab to specify auto-detect and consistency check tolerances.
To manually adjust the analytical model, click Analytical Adjust. Select an analytical element to display its direct manipulation controls. To make further adjustments, use the Modify tools: Align, Move, Pin and Delete. After you have completed adjusting the analytical element, click Finish to save changes.
You can reset an analytical element to its original shape or location by clicking Analytical Reset and selecting the element.
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Wall Instance Properties - Help
Help - Change wall instance properties to modify its location line, base and top constraints, height, and more.
Change wall instance properties to modify its location line, base and top constraints, height, and more.
A location line for the wall at the specified plane. The wall location line remains the same for that wall, even if the type changes.
Location Line Offset (for walls used as panels only)
Offsets the wall panel the specified distance and in a direction perpendicular to the face of the curtain wall.
Base Constraint - The base level of the wall. For example, Level 1.
The base level of the wall. For example, Level 1.
Base Offset - The wall's height from its base constraint. This property is available only when the Base Constraint is set to a level.
The wall's height from its base constraint. This property is available only when the Base Constraint is set to a level.
Base Is Attached - Indicates whether the base of the wall is attached to another model component, such as a floor (read-only).
Indicates whether the base of the wall is attached to another model component, such as a floor (read-only).
Base Extension Distance - The distance you have moved the base of the layers in a wall. See Compound Structure. This parameter is enabled when layers of a wall are extendable.
The distance you have moved the base of the layers in a wall. See Compound Structure. This parameter is enabled when layers of a wall are extendable.
Top Constraint - Wall height extends to the value specified in Unconnected Height.
Wall height extends to the value specified in Unconnected Height.
Unconnected Height - The height of the wall when it is sketched, measured upwards from its base.
The height of the wall when it is sketched, measured upwards from its base.
Top Offset - The offset of the wall from the top level. This parameter is enabled only when the Top Constraint is set to a level.
The offset of the wall from the top level. This parameter is enabled only when the Top Constraint is set to a level.
Top is Attached - Indicates whether the wall top is attached to another model component, such as a roof or ceiling (read-only).
Indicates whether the wall top is attached to another model component, such as a roof or ceiling (read-only).
Top Extension Distance - The distance you have moved the top of the layers in a wall. See Compound Structure. This parameter is enabled when layers of a wall are extendable.
The distance you have moved the top of the layers in a wall. See Compound Structure. This parameter is enabled when layers of a wall are extendable.
Room Bounding - If selected, the wall is part of a room boundary. If cleared, the wall is not part of a room boundary. This property is read-only before creating a wall. After you draw the wall, you can select it and then modify this property.
If selected, the wall is part of a room boundary. If cleared, the wall is not part of a room boundary. This property is read-only before creating a wall. After you draw the wall, you can select it and then modify this property.
Related to Mass - Indicates that the element was created from a mass element. This is a read-only value.
Indicates that the element was created from a mass element. This is a read-only value.
Structural - Structural Usage
Structural Usage - The structural usage of the wall. This property is read-only before creating a wall. After you draw the wall, you can select it and then modify this property.
The structural usage of the wall. This property is read-only before creating a wall. After you draw the wall, you can select it and then modify this property.
A label applied to a wall. Usually a numeric value. This value must be unique for each wall in a project. Revit warns you if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Reviewing Warning Messages.
Categorize as - Indicates whether the wall panel should schedule as a curtain panel or a wall.
Indicates whether the wall panel should schedule as a curtain panel or a wall.
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Historic preservation - This article is about the preservation of cultural heritage. For cultural heritage as a concept, see Cultural heritage. For vocation and practice of managing cultural heritage, see Cultural heritage management.
This article is about the preservation of cultural heritage. For cultural heritage as a concept, see Cultural heritage. For vocation and practice of managing cultural heritage, see Cultural heritage management.
Demolition of the former Penn Station concourse raised public awareness about preservation.
Historic preservation (US), heritage preservation or heritage conservation (UK), is an endeavor that seeks to preserve, conserve and protect buildings, objects, landscapes or other artifacts of historical significance. It is a philosophical concept that became popular in the twentieth century, which maintains that cities as products of centuries development should be obligated to protect their patrimonial legacy.[1] The term refers specifically to the preservation of the built environment, and not to preservation of, for example, primeval forests or wilderness.[2]
The ruins of Berkhamsted castle (viewed from its Norman motte) and Berkhamsted Common were the location of two successful early preservation events in the nineteenth century. (Enlarged: A train passes Berkhamsted castle, on an embankment that was once part of the castle's outer defences.)
Many historic sites were damaged as the railways began to spread across the UK; including Trinity Hospital and its church in Edinburgh, Furness Abbey, Berwick and Northampton Castle, and the ancient walls of York, Chester and Newcastle. In 1833 Berkhamsted Castle became the first historic site in England officially protected by statute under the London and Birmingham Railway Acts of 18331837, though the new railway line in 1834 did demolish the castle's gatehouse and outer earthworks to the south.[3]
Another early preservation event also occurred at Berkhamsted. In 1866, Lord Brownlow who lived at Ashridge, tried to enclose the adjoining Berkhamsted Common with 5-foot (2 m) steel fences in an attempt to claim it as part of his estate. In England from early Anglo-Saxon times, Common land was an area of land which the local community could use as a resource. Across England between 1660 and 1845, 7 million acres of Common land had been enclosed by private land owners by application to parliament. On the night of 6 March 1866, Augustus Smith MP led gangs of local folk and hired men from London's East End in direct action to break the enclosure fences and protect Berkhamsted Common for the people of Berkhamsted in what became known nationally as the Battle of Berkhamsted Common.[4][5][6] In 1870, Sir Robert Hunter (later co-founder of the National Trust in 1895) and the Commons Preservation Society succeed in legal action that ensured protection of Berkhamsted Common and other open spaces threatened with enclosure. In 1926 the common was acquired by the National Trust.[7][8][9]
John Lubbock, MP was a moving force behind the implementation of the Ancient Monuments Protection Act 1882.
By the mid 19th century, much of Britain's unprotected cultural heritage was being slowly destroyed. Even well-meaning archaeologists like William Greenwell excavated sites with virtually no attempt at their preservation, Stonehenge came under increasing threat by the 1870s. Tourists were chipping off parts of the stones or carving their initials into the rock. The private owners of the monument decided to sell the land to the London and South-Western Railway who stated that the monument was "not the slightest use to anyone now".[10] John Lubbock, an MP and botanist emerged as the champion of the country's national heritage. In 1872 he personally bought private land that housed ancient monuments in Avebury, Silbury Hill and elsewhere, from the owners who were threatening to have them cleared away to make room for housing. Soon, he began campaigning in Parliament for legislation to protect monuments from destruction. This finally led to the legislative milestone under the Liberal government of William Gladstone of the Ancient Monuments Protection Act 1882. The first government appointed inspector for this job was the archaeologist Augustus Pitt-Rivers. This legislation was regarded by conservative political elements as a grave assault on the individual rights of property of the owner, and consequently, the inspector only had the power to identify endangered landmarks and offer to purchase them from the owner with his consent. The Act only covered ancient monuments and explicitly did not cover historic buildings or structures. In 1877 the Society for the Protection of Ancient Buildings was founded by the Arts and Crafts designer William Morris to prevent the destruction of historic buildings, followed by the National Trust in 1895 that bought estates from their owners for preservation.[11]
Tattershall Castle, Lincolnshire, a medieval manor house had been put up for sale in 1910 with its greatest treasures, the huge medieval fireplaces, still intact. However, when an American bought the house they were ripped out and packaged up for shipping. The former viceroy of India, George Curzon, 1st Marquess Curzon of Kedleston, was outraged at this cultural destruction and stepped in to buy back the castle and reinstall the fireplaces. After a nationwide hunt for them they were finally found in London and returned.[12] He restored the castle[13] and left it to the National Trust on his death in 1925. His experience at Tattershall influenced Lord Curzon to push for tougher heritage protection laws in Britain, which saw passage as the Ancient Monuments Consolidation and Amendment Act 1913.
The new structure involved the creation of the Ancient Monuments Board to oversee the protection of such monuments. Powers were given for the board, with Parliamentary approval, to issue preservation orders to protect monuments, and extended the public right of access to these. The term "monument" was extended to include the lands around it, allowing the protection of the wider landscape.[14]
The preservation for the benefit of the Nation of lands and tenements (including buildings) of beauty or historic interest and, as regards lands, for the preservation of their natural aspect, features and animal and plant life. Also the preservation of furniture, pictures and chattels of any description having national and historic or artistic interest.[15]
In the early days, the Trust was concerned primarily with protecting open spaces and a variety of threatened buildings; its first property was Alfriston Clergy House and its first nature reserve was Wicken Fen. Its first archaeological monument was White Barrow. The focus on country houses and gardens, which now comprise the majority of its most visited properties, came about in the mid 20th century, when it was realised that the private owners of many of these properties were no longer able to afford to maintain them.
English Heritage formed in 1983, is a registered charity that looks after the National Heritage Collection in England.[17] This comprises over 400 of England's historic buildings, monuments and sites spanning more than 5,000 years of history. Within its portfolio are Stonehenge, Dover Castle, Tintagel Castle and the best preserved parts of Hadrian's Wall.
Originally English Heritage was the operating name of an executive non-departmental public body of the British Government, officially titled the Historic Buildings and Monuments Commission for England, that ran the national system of heritage protection and managed a range of historic properties.[18] It was created to combine the roles of existing bodies that had emerged from a long period of state involvement in heritage protection. In 1999 the organisation merged with the Royal Commission on the Historical Monuments of England and the National Monuments Record (England), bringing together resources for the identification and survey of England's historic environment. On 1 April 2015, English Heritage was divided into two parts: Historic England, which inherited the statutory and protection functions of the old organisation, and the new English Heritage Trust, a charity that would operate the historic properties, and which took on the English Heritage operating name and logo.[17][18][19] The British government gave the new charity an 80 million grant to help establish it as an independent trust, although the historic properties remained in the ownership of the state.
In the United States one of the first historic preservation efforts was the Washington's Headquarters State Historic Site, in Newburgh, New York. This property has the distinction of being the first-ever property designated and operated as a historic site by a U.S. state, having been so since 1850.
Another early historic preservation undertaking was that of George Washington's Mount Vernon in 1858.[20] Founded in 1889, the Richmond, Virginia-based Preservation Virginia (formerly known as the Association for the Preservation of Virginia Antiquities) was the United States' first statewide historic preservation group.[21][22] The American Scenic and Historic Preservation Society was formed in 1895 as the first American organization of its kind in the United States that did not limit its activities to a single historic place or object. The Society operated as a national organization to: protect the natural scenery and the preservation of historic landmarks; to preserve landmarks and records of the past or present; to erect memorials and promote appreciation of the scenic beauty of America.[23]
The architectural firm of Simons & Lapham (Albert Simons and Samuel Lapham) was an influential supporter of the nation's first historic preservation ordinance in Charleston, South Carolina in 1930, affording that city a regulatory means by which to prevent the destruction of its historic building stock. In 1925, efforts to preserve the historic buildings of the French Quarter in New Orleans led to the creation of the Vieux Carr Commission and later, to the adoption of a historic preservation ordinance.[24][25]
The preservation of this historic building in Washington, D.C., resulted in an award for Excellence in Historic Preservation by the local government.[26]
The US National Trust for Historic Preservation, another privately funded non-profit organization, began in 1949 with a handful of structures and has developed goals that provide "leadership, education, advocacy, and resources to save America's diverse historic places and revitalize our communities" according to the Trust's mission statement. In 1951 the Trust assumed responsibility for its first museum property, Woodlawn Plantation in northern Virginia. Twenty-eight sites in all have subsequently become part of the National Trust, representing the cultural diversity of American history. In New York City, the destruction of Pennsylvania Station in 1964 shocked many nationwide into supporting preservation. The 1960s proved advantageous with new laws and international agreements extending preservation "from ancient monuments to whole districts and buildings a few decades old."[27] On an international level, the New York-based World Monuments Fund was founded in 1965 to preserve historic sites all over the world.
Under the direction of James Marston Fitch, the first advanced-degree historic preservation program began at Columbia University in 1964.[28] It became the model on which most other graduate historic preservation programs were created.[29] Many other programs were to follow before 1980: M.A. in Preservation Planning from Cornell (1975); M.S. in Historic Preservation from the University of Vermont (1975); M.S. in Historic Preservation Studies from Boston University (1976); M.S. in Historic Preservation from Eastern Michigan University (1979) and M.F.A. in Historic Preservation was one of the original programs at Savannah College of Art & Design. James Marston Fitch also offered guidance and support towards the founding of the Master of Preservation Studies Degree within the Tulane School of Architecture[30] in 1996.[31] The M.Sc. in Building Conservation degree program is offered by the School of Architecture at Rensselaer Polytechnic Institute in Troy, New York. In 2005, Clemson University and the College of Charleston created an M.S. degree program based in Charleston, SC. The first undergraduate programs (B.A.) appeared in 1977 from Goucher College and Roger Williams University (then called Roger Williams College), followed by Mary Washington College in 1979.[32] As of 2013[update] there were more than fifty historic preservation programs offering certificates, associate, bachelor's, and master's degrees in the United States.[33] Under the direction of Jorge Otero-Pailos, the first PhD in Historic Preservation in the United States was founded at Columbia Graduate School of Architecture, Planning and Preservation in 2018.[34]
All of Austalia's major cities have had historic or heritage preservation establishments and legislation in place since the mid to late 1970s, though destruction or outright demolition of historic buildings continues in most Australian cities to this day, subject to council or planning approval, particularly outside of the city centres in historic neighbourhoods.[35][36] Melbourne was founded in 1835 and grew enormously in wealth and prosperity following the 1850s gold rush, which resulted in a construction boom: large edifices were erected to serve as public buildings such as libraries, court houses, schools, churches, and offices. This led to a period where Melbourne became known as "Marvellous Melbourne", boasting the largest collection of Victorian architecture outside of England. However, in the years that followed, and as the thousands of Australian soldiers arrived back from the battlefields following the end of World War I there emerged a sense of renewed pride and a willingness to forget the dark days of war and distance Australian from its Victorian origins, considered "unfashionable" or "outdated" by some. The Council of the City of Melbourne was no doubt buoyed by this new nationalistic pride and put in place schemes to modernize the city which included increasing the building height limit and removing some of the Victorian era cast ironwork. In the years leading up to World War II the Whelan the Wrecker firm had already pulled down thousands of structures in both the city and surrounding suburbs, as Melbourne became particularly conscious of International Modernism. James Paul Whelan's obituary of 1938 suggests that his company had the task of demolishing up to 98% of buildings marked for removal in the city alone.[37] The rise of this International Modernism saw a new approach that valued replacing older, elaborate inefficient buildings with new ones. An early example of this was a City of Melbourne by-law in 1954 that mandated the demolition of all posted cast-iron verandas,[38] thought to be dangerous as well as old fashioned, in order to 'clean up' the city before the 1956 Summer Olympics.
Sydney (Australia's oldest city) was also affected by the International Modernism period and also suffered an extensive loss of its Victorian architecture, something that subsisted well into the 1980s. From the 1950s onwards, many of Sydney's handsome sandstone and masonry buildings were wiped away by architects and developers who built "brown concrete monstrosities" in their place. The 1980s saw "uncomfortable pastiches of facades with no coherence and little artistic merit".[39] Green bans in Australian cities such as Sydney and Melbourne came into effect in the 1970s and the Australian Heritage Commission (AHS), was established by the Federal Government in 1975 by the Australian Heritage Commission Act 1975 as the first body to manage natural and cultural heritage in Australia until its demise in 2004.[40] It was responsible for the Register of the National Estate. The Australian National Heritage List was established in 2003. Controversy arose in 2016 in Melbourne after the historic Corkman Irish Pub was illegally demolished overnight, resulting in the State Planning Minister pursuing an order (via the Victorian Administrative Appeals Tribunal) for the two-storey pub to be rebuilt.[41] The site owners were fined AUD$1.325 million after pleading guilty to the process.
In the city of Adelaide, large public protests erupted in the 1980s regarding the 1983 campaign to save the Aurora Hotel in Hindmarsh Square, which had been recommended for listing on the city heritage register but refused because the site was to be redeveloped.[42] The protest led to the emergence of Aurora Heritage Action, Inc. (AHA), which became the most vocal heritage lobby group in Adelaide during the decade, often working in cooperation with residents' associations and later the National Trust. While governments were urged to protect the traditional character of Adelaide, capital became more widely available for development. The large increase in property development from 1987 increased opposition to further demolition of Adelaide's historic buildings. Local councils and lobbyists alike aimed to expand the horizon of heritage to protect historic precincts across the city, even if buildings within those precincts did not warrant heritage listing. The Bannon government slowly responded to public demand and introduced historic (conservation) zones through a revision to the Planning Act (1982) in 1989. Not regulated by the Planning Act, the City of Adelaide endeavoured to create on a similar scheme, which became known as the townscape initiative, facilitating one of the most destructive political debates in the council's history.
In Canada, the phrase "heritage preservation" is sometimes seen as a specific approach to the treatment of historic places and sites, rather than a general concept of conservation. "Conservation" is taken as the more general term, referring to all actions or processes that are aimed at safeguarding the character-defining elements of a cultural resource so as to retain its heritage value and extend its physical life.
Victor de Stuers is widely considered the man who started historic preservation in the Netherlands. In 1875 the first national department for conservation was established[43] and de Stuers was appointed as the first legal secretary at the Ministry of Home Affairs as chief of the brand new Department of Arts and Sciences. He was the driving force behind Monumentenzorg (Foundation for Historic Preservation), helped found the Rijksmuseum (National Museum) and the Rijksarchief (National Archives).[44][45]
However, it was not until the 20th century that there was national legislation on historic preservation. In 1961 the Monumentenwet (Monuments Act) was passed. It defined that any physical building or space that was at least fifty years old and which are of general interest because of their beauty, their meaning to science or their social value and must thus be preserved.[46][47] In 1988 this Act was replaced by the Monumentenwet 1988 (Monuments Act 1988)[48] and in 2015 by the Erfgoedwet (Heritage Law).[49]
In 1973, the NGO Monumentenwacht (Monument Watch) was founded with the purpose of providing preventative measures of maintenance for historic buildings. As the majority of the historic preservation programs in the Netherlands, this program is decentralized, managed on the provincial level.[50] Owners of heritage buildings can subscribe to the services of Monumentenwacht and receive regular visits for inspection. The costs are covered through a combination of national and provincial subsidies.[51]
A special kind of preservation that takes place in the Netherlands is the preservation of maritime heritage. Maritime trade was the Dutch specialty which shaped much of their culture and as a country that is 50% under sea level the Dutch history is closely intertwined with water.[52] There are maritime museums in both Amsterdam and Rotterdam that tell the story of the Dutch maritime heritage, but there is not much legal documentation on how to preserve it. For example, according to Sarah Dromgoole,[53] shipwrecks from The Dutch East India Company are found all around the world, which are still property of the Netherlands, but the Dutch government rarely takes responsibility for this property that is found outside of their territory.[54]
In North Macedonia, historic preservation falls under the overarching category of cultural heritage preservation according to the Law on Protection of Cultural Heritage ( ). According to this law, which the Macedonian Parliament approved in March 2004, there are three types of cultural heritage: immovable, movable, and intangible. Historical preservation is represented by the protection of monuments and monumental entireties under immovable cultural heritage, and historical items under movable cultural heritage.[55]
Although this Law was the first nation-wide establishment of regulations for historic preservation since North Macedonia gained independence from Yugoslavia on September 8, 1991, several organizations throughout the 20th century have encompassed efforts of historic preservation.
The Central office for protection of cultural monuments and natural rarities of the Socialist Republic of Macedonia has existed since 1949. In 1960, the Central Office was renamed to National office for protection of cultural monuments, and granted the status of an independent cultural institution, with authority to execute activities of historic preservation. After the establishment of the Law on Protection of Cultural Heritage in 2004, the Ministry of Culture once again renamed the office to National center for conservation and narrowed down its responsibilities to dealing solely with preservation of immovable cultural heritage.[56]
Other organizations which have contributed to the efforts of historic preservation are the Macedonian National Committee of ICOMOS and the NI Institute for Protection of Monuments of Culture and Museum-Ohrid.
The International Council on Monuments and Sites (ICOMOS) established their branch in North Macedonia in 1995 through the initiative of 43 conservationists from Macedonia. The guiding principles of the Macedonian National Committee of ICOMOS are raising the national consciousness about the importance of historic and cultural heritage, decentralization of the discourse about heritage, and effective monitoring of the status of cultural and historic heritage in the country.[57]
The NI Institute for Protection of Monuments of Culture and Museum - Ohrid is the second oldest institutions for historical preservation established in 1952. In 1956 the institute was granted authority to protect movable and immovable cultural and historic heritage in the Ohrid region. The institute has since executed numerous efforts for historic preservation, most notably aiding the recognition of the city of Ohrid as a UNESCO site of cultural heritage in 1979.[58]
Today, the main authority for historic preservation is the Cultural Heritage Protection Office ( ). The Office is an independent governmental organization under the Ministry of Culture, divided into three departments:
Identification, Protection and Use of Cultural Heritage - Prevention and Supervision
Prevention and Supervision - Documentation, International Cooperation and Administrative Affairs[59]
Documentation, International Cooperation and Administrative Affairs[59]
However, these laws are not comprehensive and limited in scope: the Antiquities Law only applies itself to buildings or artifacts dated before 1700 BC. So while efforts discovering and protecting anything older than 1700 BC are well protected, anything from later historical periods is not under the protection of this law. The Planning and Building Law discusses the overall management and regulation of land use in Israel. It has been through several changes and amendments specifically regarding preservation,[62] but over the years it hasn't been enforced and many historical sites were destroyed, as the state was prioritizing developmental and economic interests.
During the 1960s, the issue of preservation was gaining public awareness, and as a response to the destruction of Herzliya Hebrew Gymnasium (one of the first educational institutions in Israel) in 1959, a wave of shock and anger led to extensive public debate.[63]
In 1984, The Council for Conservation of Heritage Sites in Israel was established, at the recommendation of the Knesset and the Committee of Education. Its aims include locating remains of historic settlements, protect and conserve them as well as developing conservation principles that are specific to Israel's historic situations and are aligned with international standards.[64] The council used to operate under the Society for the Protection of Nature in Israel but in 2008 registers as an independent non-profit. Today, it is the organization responsible for the most historical preservation endeavors as well as efforts to add amendments to existing laws to provide a comprehensive and effective framework for preservation in Israel.[65]
A different, separate effort in preservation comes from the Israeli Defense Force (IDF). The IDF surveyed 94 military bases and found that about 80 of them include sites worth preserving, and for each of these bases there is a preservation plan.[66] The IDF is working towards maintaining these building as well as communicating their value to the soldiers in these bases. Buildings include Knights Templar sites, old military bases used by the British or German or buildings from the Ottoman period.
A historic district in the United States is a group of buildings, properties, or sites that have been designated by one of several entities on different levels as historically or architecturally significant. Buildings, structures, objects and sites within a historic district are normally divided into two categories, contributing and non-contributing. Districts greatly vary in size, some having hundreds of structures while others have just a few.
The U.S. federal government designates historic districts through the U.S. Department of Interior, under the auspices of the National Park Service. Federally designated historic districts are listed on the National Register of Historic Places.[67] Historic districts allows rural areas to preserve their characters through historic preservation programs. These include "Main Street" programs that can be used to redevelop rural downtowns. Using historic preservation programs as an economic development tool for local governments in rural areas has enabled some of those areas to take advantage of their history and develop a tourism market that in turn provides funds for maintaining an economic stability that these areas would not have seen otherwise.[68][69]
In 1835, the English poet William Wordsworth described the Lake District as a "sort of national property, in which every man has a right and interest who has an eye to perceive and a heart to enjoy."[70]
It was, however, the United States that led the world in the creation of National Parks, areas of unspoiled natural wilderness, where the intrusion of civilization are intentionally minimal.[citation needed]
The Department of the Interior designated several areas of Morristown, New Jersey as the first historic park in the United States national park system. It became designated as the Morristown National Historical Park.[71] The community had permanent settlements that date to 1715, is termed the military capital of the American Revolution, and contains many designations of sites and locations. The park includes three major sites in Morristown.
According to UNESCO's 1972 World Heritage Convention, landscapes and sites of outstanding universal value can be designated as World Heritage Sites. The World Heritage Convention encompasses historic preservation under the category of cultural heritage. According to Article 1 of the convention, monuments, groups of buildings, and sites which are of outstanding universal value from the point of view of history, art or science are to be designated cultural heritage.
A requirement of such designation is that the designating nation has appropriate legal, scientific, technical, administrative and financial measures in place to identify, protect, conserve, present, and rehabilitate world heritage sites. However, according to Article 6 of the convention, while sovereignty of the State where the site is located is not to be compromised, the State acknowledges that protection of heritage sites is a duty of the entire international community.[73]
The World Heritage convention's counterpart, The World Heritage Committee,[74] is the body responsible for the practical implementation of the convention as well as managing and deciding how to use the World Heritage Fund. The committee also gets to have the final say when determining whether a property will be included in the World Heritage List.
The Committee meets once a year and includes representatives from 21 states that are part of the States Parties. Yearly reports are available to the public on the World Heritage website and include outlines of decisions made, outcomes, working documents and various reports.[75]
International partner of UNESCO is Blue Shield International. From a national and international perspective, there are many cooperations with Blue Shield organizations and with United Nations peacekeeping to ensure the sustainable existence of cultural assets.[76][77][78][79]
The historic experience of females has been overlooked for a majority of human history. Since the 1990s, more effort has been put forth to improve the presentation of women's history. "Guidebooks to women's landmarks have sometimes failed to distinguish between the presence of historic resources and subsequent construction on sites of significance in women's history, making an actual visit to the site a somewhat disappointing experience for visitors."[80]
Although preservation efforts can have benefits for the owners of historical buildings, such as tax cuts and subsidies, there are also drawbacks.
One such drawback is that after a neighborhood has been designated to be historically preserved, there is less construction. On the long term this can affect the value of property and investment in housing, both in the neighborhood itself and the neighborhoods directly surrounding it.[81]
A second concern that has been raised is that buildings that need to be historically preserved are sometimes still inhabited. In some cases their inability to make changes to the building can lead to dangerous or unhealthy situations for residents.[82]
It is not true that nothing could be changed or renovated, but the owner of the building would need to ask permission at the appropriate preservation society, slowing the process down severely. The exact policies are country dependent.[83]
Eugne Viollet-le-Duc (1814-1879): French architect who restored Gothic buildings and believed that restoration could improve on the past.
Ann Pamela Cunningham (18161875): influential in saving Mount Vernon (plantation) from demolition and founding the Mount Vernon Ladies' Association, one of the first preservation organizations in the United States (est. 1854).[84]
John Ruskin (1819-1900): English art critic who established the basic theory of preservation (retention of status quo).
Augustus Pitt Rivers (18271900): Britain's first Inspector of Ancient Monuments.
John Lubbock (1834-1913): campaigned for legal protection for ancient monuments and saved Avebury from destruction at the hand of its private owners.
Camillo Boito (1836-1914): Italian architect who tried to reconcile the conflicting views of Viollet-le-Duc and Ruskin, inspiring modern legislation on restoration in several countries
Victor de Stuers (1843-1916): Dutch art historian, lawyer, civil servant and politician. First legal secretary at the Ministry of Home Affairs as chief of the brand new Department of Arts and Sciences.
William Sumner Appleton (1874-1947): Founder of the Society for the Preservation of New England Antiquities (now Historic New England) in 1910, and widely considered as the U.S.'s first professional preservationist.
Charles E. Peterson (19062004): considered to be the "founding father" of historic preservation in the United States.
James Marston Fitch (1909-2000): educator, author, critic and design practitioner made a major contribution to the philosophical basis of the modern preservation movement and trained and inspired generations of preservationists.
William J. Murtagh: first Keeper of the National Register of Historic Places in the United States and significant contributor to the literature of the discipline.[85]
Lee H. Nelson: worked for Charles E. Peterson at the National Park Service's Historic American Buildings Survey and helped to formulate national policies on historic preservation.
Walter Muir Whitehill: Chairman of the Whitehill Report in the late 1960s, which established the first guidelines for higher education historic preservation programs.
Harriet Tubman (1822-1913): purchased 25 acres to erect a Home for the elderly, this site would eventually serve as a memorial to her legacy.[86]
Mary McLeod Bethune (1875-1955): involved in many efforts to preserve Afro-American historic sites, established an archive on Afro-American women's history, and provided funds to key organizations with similar goals.[86]
Madam C.J. Walker (1867-1919): gave the single largest contribution for the preservation of the Frederick Douglas Home.[86]
Although volunteers continue to play a large role in historic preservation activities, the field has seen an increased level of professionalization. Today, there are many career options in historic preservation in the public, non-profit and private sectors. Institutes of secondary education (universities, colleges, etc.) in the United States offer both certificate and degree (A.A.S, B.A., B.F.A., B.S., M.A., M.F.A., M.D.S, M.H.P., M.S., and PhD) programs in historic preservation. Some pupilsat schools with such programmes availablechoose to enroll in "joint degree" programs, earning a degree in historic preservation along with one in another, related subject, often an MArch, MUP or JD degree.
Possible career fields include: - Architectural conservator
Architectural conservator - Focus specifically on the physical conservation of building materials.
Focus specifically on the physical conservation of building materials.
Architectural historian/historian - Primarily researches and writes statements expressing the historical significance of sites.
Primarily researches and writes statements expressing the historical significance of sites.
Historic preservation planner - Most are employed by local, county, state or federal government planning agencies to administer tax abatement programs, ensure compliance with local ordinances and state and Federal legislation, and conduct design reviews to ensure that proposed projects will not harm historic and archaeological resources. At the state level, they are known as a State Historic Preservation Officer while at other levels of government they may be known as a Federal or Tribal Historic Preservation Officer. Some may also serve as consultants to local governments, conducting Section 106 reviews in accordance with the National Historic Preservation Act of 1966.
Most are employed by local, county, state or federal government planning agencies to administer tax abatement programs, ensure compliance with local ordinances and state and Federal legislation, and conduct design reviews to ensure that proposed projects will not harm historic and archaeological resources. At the state level, they are known as a State Historic Preservation Officer while at other levels of government they may be known as a Federal or Tribal Historic Preservation Officer. Some may also serve as consultants to local governments, conducting Section 106 reviews in accordance with the National Historic Preservation Act of 1966.
Preservation architect - Design and develop architectural conservation plans and work specifications in consultation with Engineers, Historians and Planners, ensuring compliance with local design guidelines to protect sensitive historic building fabric. Most are employed by private architecture firms though some find work with government agencies.
Design and develop architectural conservation plans and work specifications in consultation with Engineers, Historians and Planners, ensuring compliance with local design guidelines to protect sensitive historic building fabric. Most are employed by private architecture firms though some find work with government agencies.
Employs knowledge of traditional building techniques and contemporary conservation technologies to complete the conservation, repair or restoration of historic buildings.
Preservation engineer - Work with Architects to devise conservation solutions of a structural or material -specific nature. Most are employed by private architecture and/or engineering firms.
Work with Architects to devise conservation solutions of a structural or material -specific nature. Most are employed by private architecture and/or engineering firms.
Most are employed by government agencies and private foundations to interpret the significance of historic resources for the general public.
Engage in a variety of activities concerned with historic preservation advocacy, easements, and private foundations at the local, regional, statewide, or national levels.
Ship of Theseus, a philosophical problem regarding identity of preservation and replacement
^ "Mr. Shaw-Lefevre on the Preservation of Commons". The Times. 11 December 1886. p. 10.
^ Bryson, Bill. "At Home: A Short History of Private Life" Transworld Publishers, 2010
^ Adrian Pettifer (2002). English Castles: A Guide by Counties. Boydell & Brewer. pp. 1457.
^ a b "Our History". English Heritage. English Heritage Trust. Retrieved 6 April 2015.
^ Lea, Diane. "America's Preservation Ethos: A Tribute to Enduring Ideals." A Richer Heritage: Historic Preservation in the Twenty-First Century. ed. Robert Stipe. Chapel Hill: University of North Carolina Press, 2003. p.2
^ Lindgren, James Michael. Preserving the Old Dominion: historic preservation and Virginia traditionalism. Charlottesville: University Press of Virginia, 1993. 3. Print.
^ "Scenic and Historic America: Bulletin of the American Scenic and Historic Preservation Society." ASHPS 2.1 (March 1930):3.
^ Blevins, Documentation of the Architecture of the Architecture of Samuel Lapham and the Firm of Simons & Lapham, Masters of Fine Arts in Historic Preservation Thesis, Savannah College of Art & Design, 2001
^ Ellis, Scott S. (2010). Madame Vieux Carr: the French Quarter in the Twentieth Century. University of Mississippi. p. 43.
^ Murtagh, William J. Keeping Time: The History and Theory of Preservation in America. New York: Sterling Publishing, Co., 1997.
^ Michael Tomlan. "Historic Preservation Education: Alongside Architecture in Academia." Journal of Architectural Education, Vol. 47, No. 4. (1994): 187-196.
^ "Home Page". 13 September 2015. Archived from the original on 15 August 2013. Retrieved 13 December 2013.
^ Doyle, Helen (2011). Thematic History A history of the City of Melbourne's urban environment. Context, Brunswick
^ Butler, Katelin; Bruhn, Cameron (2017). The Apartment House. Thames & Hudson. p. 100. ISBN 978-0-500-50104-7.
^ Bouwer, L.M.; Vellinga, P. (20 October 2018). Flood Risk Management in Europe. Springer Netherlands. pp. 469484. doi:10.1007/978-1-4020-4200-3_24.
^ Roger OKeefe, Camille Pron, Tofig Musayev, Gianluca Ferrari: Protection of Cultural Property. Military Manual. UNESCO, 2016.
^ Corine Wegener, Marjan Otter "Cultural Property at War: Protecting Heritage during Armed Conflict" in The Getty Conservation Institute, Newsletter 23.1, Spring 2008.
^ Li, C. (2012). The politics and heritage of race and space in San Franciscos Chinatown. In D. F. Ruggles (Ed.), On location (pp. 3759). New York, NY: Springer.
^ Barrett, J. (2016). Getting Away From "No": Straight Talk to Local Advocates. Forum Journal 30(2), 46-49. National Trust for Historic Preservation. Retrieved November 7, 2017, from Project MUSE database.
Birtchnell, Percy (1988). Short History of Berkhamsted. Berkhamsted: Book Stack. ISBN 978-187137200-7.
Cobb, John Wolstenholme. Two Lectures on the History and Antiquities of Berkhamsted. London, UK: Nichols and Sons * Jokilehto, Jukka. A History of Architectural Conservation. Oxford, UK: Butterwort/Heinemann, 1999.
Fitch, James Marston. Historic Preservation: Curatorial Management of the Built World. Charlottesville, VA: University Press of Virginia, 1990.* Munoz Vinas, Salvador. Contemporary Theory of Conservation. Amsterdam: Elsevier/Butterworth Heinemann, 2005.
Page, Max & Randall Mason (eds.). Giving Preservation a History. New York: Routledge, 2004.
Price, Nicholas Stanley et al. (eds.). Historical and Philosophical Issues in the Conservation of Cultural Heritage. Los Angeles: The Getty Conservation Institute, 1996.
Ruskin, John. The Seven Lamps of Architecture. New York: Dover Publications, 1989. Originally published, 1880. Important for preservation theory introduced in the section, "The Lamp of Memory."
Sherwood, Jennifer. "Influences on the Growth of Medieval and Early Modern Berkhamsted". In Wheeler, Michael (ed.). A County of Small Towns: the Development of Hertfordshire's Urban Landscape to 1800. Hatfied, UK: Hertfordshire.
Stipe, Robert E. (ed.). A Richer Heritage: Historic Preservation in the Twenty-First Century. Chapel Hill, NC: The University of North Carolina Press, 2003.
Tyler, Norman, Ted J. Ligibel, and Ilene R. Tyler. [2]Historic Preservation: An Introduction to its History, Principles, and Practice. New York: W.W. Norton & Company, 2018.
Viollet-le-Duc, Eugne Emmanuel. The Foundations of Architecture; Selections from the Dictionnaire Raisonn. New York: George Braziller, 1990. Originally published, 1854. Important for its introduction of restoration theory.
A label (as distinct from signage) is a piece of paper, plastic film, cloth, metal, or other material affixed to a container or product, on which is written or printed information or symbols about the product or item. Information printed directly on a container or article can also be considered labelling.
Labels have many uses, including promotion and providing information on a product's origin, manufacturer (e.g., brand name), use, shelf-life and disposal, some or all of which may be governed by legislation such as that for food in the UK[1] or United States.[2] Methods of production and attachment to packaging are many and various and may also be subject to internationally recognised standards. In many countries, hazardous products such as poisons or flammable liquids must have a warning label.
Fire extinguisher with permanent and temporary labels - Labels may be used for any combination of identification, information, warning, instructions for use, environmental advice or advertising. They may be stickers, permanent or temporary labels or printed packaging.
Labels may be used for any combination of identification, information, warning, instructions for use, environmental advice or advertising. They may be stickers, permanent or temporary labels or printed packaging.
Permanent product identification by a label is commonplace; labels need to remain secure throughout the life of the product. For example, a VIN plate on an automobile must be resistant to heat, oils and tampering; similarly, a food label must endure until the food has been used. Removable product labels need to bond until they are removed. For example, a label on a new refrigerator has installation, usage and environmental information: the label needs to be able to be removed cleanly and easily from the unit once installed.
Labels for food and beverages typically include critical information pertinent to the contents or ingredients used in a product, and may also call out to certain allergy risks such as the presence of gluten or soy. The FDA also provides standards to regulate the information provided on the labels and packaging of wine and spirits. These labels include information like brand name, class and type designation, and alcohol content.[3]
Packaging may have labeling attached to or integral with the package. These may carry pricing, barcodes, UPC identification, usage guidance, addresses, advertising, recipes, and so on. They also may be used to help resist or indicate tampering or pilferage.
In industrial or military environments, asset labeling is used to clearly identify assets for maintenance and operational purposes. Such labels are frequently made of engraved Traffolyte or a similar material.[4] They are usually tamper-evident, permanent or frangible and usually contain a barcode for electronic identification using readers. For example, the US Military uses a UID system for its assets.
Garments normally carry separate care/treatment labels which, in some regions, are subject to legislation.[5][6] These labels typically indicate how the item should be washed (e.g., machine washed vs. dry cleaning), whether bleach can be used. Textile labels may be woven into the garment or attached, and may be heat resistant (so survivable in hot-air dryers and when pressed), colorfast (so does not bleed onto the garment), washable, leather or PVC/Plastic. Printed labels are an alternative to woven labels. Some upholstered furniture and mattresses have labels that are required by law, describing the contents of the stuffing.
Textiles containing pesticides as an ingredient may also require government approval and compulsory labeling. In the USA, for example, labels have to state the pesticide registration number, statement of ingredients, storage and disposal information, and the following statement: "It is a violation of Federal Law to use this product in a manner inconsistent with its labeling. A label including a company name or identification number and a material content list may also be required.[7]
Mailing labels identify the addressee, the sender and any other information which may be useful in transit. Many software packages such as word processor and contact manager programs produce standardized mailing labels from a data set that comply with postal standards. These labels may also include routing barcodes and special handling requirements to expedite delivery.
Notebook labels are mainly used for identifying the owner and purpose of the notebook. Some information on a label may include name, contents, and date started.
Piggyback labels are made from combining two layers of adhesive substrate. The bottom layer forms the backing for the top. The label can be applied to any object as normal, the top layer can be a removable label that can be applied elsewhere, which may change the message or marking on the remaining label underneath. Often used on Express mail envelopes. Other applications include price change labels where when being scanned at the till, the till assistant can peel back the price-reduction label and scan the original barcode enabling stock flow management. These labels are also seen on magazine subscription renewals, allowing customers to re-subscribe to the magazine with an easy peel and stick label sent back.[8] Also, as the retained label is adhesive free it prevents customers from re-applying the cheaper priced labels to premium products.
Blockout labels are not see-through at all, concealing what lies underneath with a strong gray adhesive.
Laser or printer labels are generally die cut on 8.5" x 11" (US letter) or A4 sized sheets, and come in many different shapes, sizes,[9] formats and materials. Laser label material is a nonporous stock made to withstand the intense heat of laser printers and copiers. A drawback of laser labels is that the entire sheet needs to be printed before any labels are used; once labels have been removed the sheet cannot be put through the printer again without damaging the printing mechanism. Inkjet label material is a porous stock made to accept ink and dye from an inkjet printer. One of the more modern inkjet label material stocks is waterproof printable inkjet material commonly used for soap or shower gel containers.
Security labels are used for anti-counterfeiting, brand protection, tamper-evident seals and anti-pilferage seals. These combine a number of overt and covert features to make reproduction difficult. The use of security printing, holography, embossing, barcodes, RFID chips, custom printing and weak (or weakened) backings is common. They are used for authentication, theft reduction, and protection against counterfeit and are commonly used on ID cards, credit cards, packaging, and products from CDs to electronics to clothing.
Antimicrobial labels. With the growth in hospital acquired infections such as MRSA and E-Coli the use of antimicrobial labels in infection sensitive areas of hospitals are helping in combating these types of microbes.
Fold-out labels, also known as booklet, multi-page, multi-layer, or extended labels, or lablets (combined label + leaflet). Where the pack is not large enough for a single label to carry all the required information, fold-out labels are often preferred to separate leaflets, which can easily be lost. These labels are frequently seen on agricultural chemicals and consumer pharmaceuticals.
Barcode labels A large proportion of labels produced today carry barcodes, either for product identification, for traceability in items such as freight packages, and on items requiring brand authentication and protection. There are many different formats of barcodes found on labels, but one of the most commonly distributed formats is the International Article Number (EAN). This is the code used to identify retail products worldwide, and is found on almost all consumer level packaging labels.
Shrink Sleeve labels provide full 360 degree coverage on a container or bottle. Polyvinyl chloride (PVC) and Polyethylene Terephthalate Glycol-modified (PETG) are two commonly used shrink sleeve materials. Shrink sleeves can be applied to uniquely shaped bottles or standard containers and can be printed with metallic features, textured/raised features, UV inks, and Matte or Glossy texture finishes.
Label "stock" is the carrier which is commonly coated on one side with adhesive and printed on the other, and can be:
Paper - a variety of papers and paperboards can be used as labels
Latex a lithographic stock with some added latex allows the label to be much more flexible and form around certain curved objects more easily than standard paper;
Labels on a laptop. - Plastics such as acetate, vinyl, and PET film allow a variety of features, such as greater strength, stiffness, transparency and resistance to tearing. They typically require special equipment and printing methods (ultra-violet curing is common) as they do not normally print well with conventional ink. A bumper sticker is usually a vinyl label with a very strong, durable adhesive and lightfast inks. Embossing tape is "printed" by pressing raised elements similar to printing type onto it, which produces raised glyphs that look white due to discoloration of the plastic. A type known as 'destructible vinyl' is commonly used for asset labels. It combines a very thin frangible face stock with a very strong high tack adhesive, thus making the label impossible to remove without damaging it. Engraved multi-layer Traffolyte labels are frequently used in industrial situations due to their durability;
Plastics such as acetate, vinyl, and PET film allow a variety of features, such as greater strength, stiffness, transparency and resistance to tearing. They typically require special equipment and printing methods (ultra-violet curing is common) as they do not normally print well with conventional ink. A bumper sticker is usually a vinyl label with a very strong, durable adhesive and lightfast inks. Embossing tape is "printed" by pressing raised elements similar to printing type onto it, which produces raised glyphs that look white due to discoloration of the plastic. A type known as 'destructible vinyl' is commonly used for asset labels. It combines a very thin frangible face stock with a very strong high tack adhesive, thus making the label impossible to remove without damaging it. Engraved multi-layer Traffolyte labels are frequently used in industrial situations due to their durability;
Foil Aluminum foil and vapor-coated plastic films are often chosen for the bright reflective characteristics;
Thermal direct thermal label stock will change color (usually black) when heated. A heating element in the shape of letters or images can be used to create an image on the label. Custom labels can be easily be made on location in this way. A disadvantage is durability, because another heat source can ruin or obscure the image, or it may fade completely over time;
Thermal transfer for applications that cannot use thermal (thermal direct) label material because of heat source proximity or short label life, a more widely used material is the thermal transfer label printer. This material has the advantage of a much longer readable life and does not fade with time or heat. Most major manufacturers of thermal printers can be used for either thermal transfer (TT) or thermal (DT) labels. A thermal transfer ribbon will be required to print the labels. The cost of the ribbons + TT labels is similar to that of the DT labels on their own;
Thermal transfer ribbon types: - Wax is the most popular as it has some smudge resistance, and is suitable for matte and semi-gloss paper labels;
Wax is the most popular as it has some smudge resistance, and is suitable for matte and semi-gloss paper labels;
Wax and resin are smudge resistant, suitable for semi-gloss paper and some synthetic labels;
Resin is scratch and chemical resistant, suitable for coated synthetic labels;
None labels can be printed directly on adhesive without using a substrate. Labels made in this manner are extremely fragile, however, and have been rendered virtually obsolete by other printing methods such as silk screen;
The stock type will affect the types of ink that will print well on them. Corona treating or flame treating some plastics makes them more receptive to inks, coatings, and other substrates by reducing surface tension and improving overall adhesion of the plastics.
An alternative method of labelling is weaving the text directly into fabric.
Heat activated adhesives: for example, "in-mold labeling" can be part of blow molding containers and employs heat activated adhesives. Hot melt adhesives are also used.
Pressure-sensitive adhesives (also called PSA or self-stick) are applied with light pressure without activation or heat. PSA labels often have release liners which protect the adhesive and assist label handling.
Rivets used to attach information plates to industrial equipment.
Shrink wrap for printed shrinkable labels placed over packages and then heated to shrink them.
Sewing for fabrics such as clothing, tents, mattresses and industrial sacks.
Wet glue such as starch, dextrin, PVA or water moistenable gummed adhesive.
Static cling, where "stickers" have a static charge enabling them to attach without adhesive to smooth surfaces such as glass.
Pressure-sensitive label adhesives are commonly made from water-based acrylic adhesives, with a smaller volume made using solvent-based adhesives and hotmelt adhesives. The most common adhesive types are:
Permanent Typically not designed to be removed without tearing the stock, damaging the surface, or using solvents. The adhesion strength and speed can also be varied. For example, full adhesion can be nearly instant, or the label can be almost removable for a short period with full adhesion developing in minutes or hours (known as respositionable adhesives).
Peelable Adhesion is fairly strong and will not fall off in normal circumstances, but the label can be removed relatively easily without tearing the base stock or leaving adhesive behind on the old surface. The adhesive is usually strong enough to be applied again elsewhere. This type is frequently known as 'removable'. There are many different types of removable adhesives, some are almost permanent, some are almost 'ultra peelable'.
Ultra-peelable Designed principally for use on book covers and glass, when removed these adhesives labels do not leave any residue whatsoever. Adhesion is weak and only suitable for light duty applications. Normally these labels have very little adhesion to anything once they've been removed.
Freezer or frost fix Most permanent and peelable adhesives have a service temperature limit of -10 degrees Celsius, whereas freezer (otherwise known as frost fix) adhesives have a service temperature -40 degrees Celsius and are suitable for deep freeze use.
High tack A type of permanent adhesive that exhibits a high initial grab to the application surfaces, and is commonly used at higher coat weights to enable labels to adhere strongly to difficult, rough or dirty surfaces.
Labels may be supplied separately or on a roll or sheet. Many labels are pre-printed by the manufacturer. Others have printing applied manually or automatically at the time of application. Specialized high speed label printer applicators may be used to apply labels to packages; these and other methods may be subject to recognized standards.[10][11] Some labels have protective overcoats, laminates, or tape to cover them after the final print is applied. This is sometimes before application and sometimes after. Labels are often difficult to peel and apply. A label dispenser can speed up this task.
Aspects such as legibility, literacy and interpretation come into play for users of labels, and label writers therefore need some degree of professional writing skill.[12] Depending upon country or region, international standards may be applied.[13] Where literacy may be an issue, pictograms may feature alongside text, such as those advanced by CropLife International in their Responsible Use manual.[14] Labels or printed packaging may include Braille to aid users with visual impairment.
Criticism of label readability is not uncommon; for example, Canadian researchers found that medicine labels did not consistently follow legibility guidelines.[15] In some countries and industries, for example the UK (food)[16] and EU (medicines)[17] label guidelines are not legally binding (the latter using phrases such as "The type size should be as large as possible to aid readers...") and thus are unenforceable. On the other hand, countries may stipulate legal minima for readability, such as the USA's FDA on nutritional information[18] and Australia/New Zealand's code for food labels and packs.[19]
Labels may affect the environment during manufacture, use, and post-use. Choice of backings, coatings, adhesives, and liners can be strong factors. Environmental regulations and guidelines can come from many sources. Users of labels on packaging may consider some of the sustainable packaging guidelines. Based on the solid waste hierarchy, the quantity and size of labels should be minimized without reducing necessary functionality. Material content of a label should comply with applicable regulations. Life cycle assessments of the item being labeled and of the label itself are useful to identify and improve possible environmental effects. For example, reuse or recycling are sometimes aided by a label being removable from a surface.
If a label remains on an item during recycling, a label should be chosen which does not hinder the recyclability of the item.[20][21] For example, when labeled corrugated boxes are recycled, wet strength paper labels do not hinder box recycling: the PSA adhesive stays with the backing and is easily removed. Paper backings without wet strength may release their adhesives, potentially contaminating recycling efforts.[22][23] Labels can aid in recycling and reuse by communicating the material content of the item, instructions for disassembly or recycling directions. An eco-label is used on consumer products (including foods) to identify products that may be less damaging to the environment and/or humans than other related products, such as sustainable seafood encouraged by Friend of the Sea.[24]
Ink and base stock color choices commonly conform to the Pantone Matching System (PMS) colors. The Pantone system is very dominant in the label printing industry. Additionally specialty inks such as metallic, UV ink, magnetic ink, and more are available. Ink is usually transparent however it can be made opaque. It has been known for certain companies to patent "their own" color. Digital labels use process colors to replicate Pantone solid colors.
Collecting labels is a worldwide phenomenon, from labels used on matchboxes and foodstuffs (e.g., cheese), wine, to printed packages. Collectors are attracted to labels both for their influence on artistic design and the history of retailing.[25]
^ ASTM D5375 Standard Test Methods for Liner removal at High Speeds from Pressure-Sensitive Label Stock. ASTM
^ ASTM D6252 Standard Test Method for Peel Adhesion of Pressure Sensitive Label Stocks at 90 deg Angle. ASTM
^ Gold, Karen (13 June 1992). If all else fails, read the instructions. New Scientist.
^ ASTM D7298-06 Standard Test Method for Measurement of Comparative Legibility by Means of Polarizing Filter Instrumentation. ASTM
^ Gruenewald, L. E.; Sheehan, R. L. (1997). "Consider box closures when considering recycling". J. Applied Manufacturing Systems. St Thomas Technology Press. 9 (1): 2729. ISSN 0899-0956.
^ Opie, Robert (1987). The Art of the Label. Simon & Schuster. p. 140. ISBN 0671654411.
Fairley M, "Encyclopedia of Label Technology". 2nd Edition, Tarsus Publishing, 2014,ISBN 978-1910507001,
Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6
Holkham, T., "Label Writing and Planning A guide to good customer communication", Chapman & Hall 1995, ISBN 0-7514-0361-X
ASTM D7932 Standard Specification for Printed, Pressure-Sensitive Adhesive Labels for Use in Extreme Distribution Environments
Tag: lateral justification - Many projects require the offsetting of structural framing members in the horizontal direction and Revit Structure provides only one tool to enable the Horizontal offset of a structural frame. This is called lateral justification and is often quite limiting as it only offsets the member about the analytical line and does not allow full control.
Many projects require the offsetting of structural framing members in the horizontal direction and Revit Structure provides only one tool to enable the Horizontal offset of a structural frame. This is called lateral justification and is often quite limiting as it only offsets the member about the analytical line and does not allow full control.
You can try this by selecting a universal beam and choosing lateral justification and setting Centre, Side 1 and Side 2 and see the results. Make sure that you have the analytical model switched on so you can see the physical and analytical positions.
It is possible to create your own parameter to control the horizontal offset of the physical framing member whilst keeping the analytical model unchanged. Of course, you can edit the analytical model if necessary.
To begin, select your universal beam and choose edit family from the right click menu. This will open the family editor. You will see the 3D model of your beam. You are actually seeing two 3D sweeps, one model for the medium level of detail without a root fillet radius and the fine model which contains the root fillet.
Select both models as shown below and then choose the associate family parameter command.
In the associate family parameter dialog box, choose Add parameter. Add a parameter called Horizontal Offset, make it an instance parameter and group this under Constraints as shown below.
Click OK to both dialog boxes and then load this into your current project. Select a universal beam and you will now be able to control the horizontal offset as shown below.
Note that you will also have to edit the symbolic lines (Hidden detail) to make the beam look correct in a plan view. I will create a video at a later point to show this process.
Oxford English and Spanish Dictionary, Synonyms, and Spanish to English Translator
Main meanings of mark in English - mark1
mark1 - Pronunciation /mk/
Pronunciation /mk/ - noun
noun - 1. Mark:A small area on a surface having a different colour from its surroundings, typically one caused by damage or dirt.
1. Mark:A small area on a surface having a different colour from its surroundings, typically one caused by damage or dirt.
the blow left a red mark down one side of her face
More example sentences - The yellow sponged raked over the arm viciously causing a deep red scuff marks to surface.
The yellow sponged raked over the arm viciously causing a deep red scuff marks to surface.
Looking up, she saw several holes dotted along its surface, burned scorch marks surrounding the edges.
Oh boy did I do a lot of damage his whole face was either covered in red marks or a bruise.
Always carefully check goods in the shop for damage, tears or marks, particularly if the item is in a sale.
Splotched with marks of dirt and even blood, it looked filthy and gave her a conscious feeling of someone living in the gutters.
The films are not well preserved, so there are plenty of scratches and burn marks, and dirt on the prints.
This hypothesis well explains why even the same cave has different patterns of calving and different chisel marks.
The bullet holes and blood seem even more disturbing when they are left as white marks on a dark surface.
I observed her curiously as she hesitantly took off her coat, wincing as she did so; my eyes were called to her neck which was flawed mercilessly with red marks around the left side.
William sat back, sulking at the red mark on the side of his cheek.
I also noticed tire marks in dirt on the right side of the road.
He was left with puncture marks and a severe gash on his nose and severe damage to his top lip.
The lower screen on the one I've got here is scratched, but they're only surface marks - it's not as though the screen is really damaged, just the covering.
She lifted her right hand and lightly ran a finger over the red marks on her cheeks which she knew were the result of frostbite.
Grain is present throughout the feature as well as lots of dirt, reel marks, and scratches.
There are also creams available at make up counters that reduce the look of red or purplish marks (it is usually green or purple in the bottle).
Is the blanket showing any signs of damage such as scorch marks, broken ties, or do any of the wires inside the blanket feel like they are broken or unevenly spaced?
Improvements in the technology behind its production mean that many papers are now more resistant to grubby marks and other damage.
I must warn you though that your wheels will leave marks on the surface you're sliding on.
No tool marks survive on the surface of the boat as a result of repeated scourings by wind, sand and water.
1.1A spot, area, or feature on a person's or animal's body by which they may be identified or recognized.
he was five feet nine, with no distinguishing marks
More example sentences - I recognized individuals by natural marks such as black spots on the back or head and their toe-clip pattern.
I recognized individuals by natural marks such as black spots on the back or head and their toe-clip pattern.
He had no tattoos or other distinguishing body marks but he had two crowns on teeth to the front of his right upper jaw, possibly suggesting an accident or sporting injury.
The man was not immediately identified as the former Iraqi leader but marks on his body and other undisclosed information quickly indicated they had their man.
Even identifying marks will now be included on that state's register.
These marks included distinctive spots and stripes on the back, shoulders, hips, hind legs, and rump of the gerbils.
2. Mark: a line, figure, or symbol made as an indication or record of something.
the first syllable has a stress mark - More example sentences
More example sentences - Here are some useful sites for anyone needing to display diacritical marks, mathematical symbols, etc.
Here are some useful sites for anyone needing to display diacritical marks, mathematical symbols, etc.
The stress marks might seem quaint to us; but McGuffey believed that rhythm and harmony have not only an aesthetic but also a moral value.
Although most of the headstones are severely weathered and illegible, cemetery staff will record all legible marks and inscriptions before removing the stones.
EcoRI sites determined by restriction mapping are shown as tick marks on the genomic clones and as half-tick marks below the top line.
At the same time, line up the center marks on the template with your center axis mark on the ski.
Using the edge of your workbench as a straightedge for the square, draw a set of nice black lines across the mounting marks, so you have a good visual reference.
The skaters may be placed in the correct order, which is all that counts at the bottom line, but the marks are now totally meaningless.
Okay, you've got both skis mounted with the toe units, they're epoxied and the boot-heel center marks line up perfectly with those on your skis.
This section measures knowledge of spelling rules and stress marks in Spanish.
Line the mark on your stock up with the doweling jig that corresponds to the size of the dowel you are using.
Google ignores most punctuation, except apostrophes, hyphens and quote marks.
Ancient stories are handed down from the days before we learned to store our thoughts in marks on paper or lines carved in stone, and the Gods live in these stories.
As these marks are studied and recorded they can be of great assistance with accurate dating, particularly where company records still exist.
Bach, of course, left very few indications or interpretive marks as to how his music should go.
The mark looked like the symbol for life that the mystics had created years ago.
Accented and umlauted vowels, and diacritical marks on consonants must be avoided, because they act as roadblocks and break the speed of a typist.
As much as it pains me to admit it, there may not be an important moral argument for using an apostrophe rather than a tick mark.
It was a confusing mass of symbols and half-familiar marks.
So the fact that this building is expensive is a mark of its quality.
Somehow, the brand of the magazine becomes the mark of quality rather than the individual work in it.
Flags were flying at half mast as a mark of respect for the Duke of Norfolk who died two days ago at the age of 86, the Arundel ground being part of the Duke's estate.
An impressed stamp on the blade tang is usually the mark of a lower quality blade.
If the mark of a quality referee is to pass unnoticed, then Poll succeeded, albeit with the complicity of a set of almost angelic players.
The rehabilitation of the bridges and roads should be a mark of quality for lengthy life of the facilities.
The red and white ballon flag flew at half mast as a mark of respect to the two people who had earlier died in a horrible crash.
It is also right that flags in the city should be at half mast, as a mark of respect to the dead and their families.
Corus corporate flags at plants across Britain and Europe are flying at half mast as a mark of respect.
Marching is a mark of respect, especially to those who gave their lives.
And as a mark of respect for the victims of the tsunami the national flag will be flown at half mast on civic buildings next week.
Both sides of the crossing were covered with flowers by mourners, who left bouquets and countless soft toys as a mark of respect.
As a mark of respect all club activities have been cancelled this weekend.
He ran a haulage firm and wanted me to take over, but I never fancied it so I named my butcher's shop after his firm as a mark of respect.
The wonderful guard of honour formed by both these groups was a fitting mark of respect and was well deserved.
As a mark of respect and in order to allow students to attend the service, all lectures and classes in Italian were cancelled.
So every time I was in a bar after that, I would add a Jameson on to my order and leave it on the bar as a mark of respect for a mate who couldn't have a drink.
But a raid of her house and seizure of her property is the mark of an out of control incipient police state.
WiFi in airport departure lines is the mark of civilised countries.
There are lists of what to do in the event of arrest - and also guides to getting arrested as this is the mark of a high quality protester.
2.2A written symbol made on a document in place of a signature by someone who cannot write.
He might have obtained better results simply by taking the differences in the lanes' staggered starting marks for an appropriate track event.
More example sentences - He pocketed the penultimate race even after having to re-round the starting mark as he had jumped the start.
He pocketed the penultimate race even after having to re-round the starting mark as he had jumped the start.
The handicapper's job is to make the race as competitive as possible by giving each competitor a mark off which to run.
The runners now toed this mark, each competitor leaning forward with his eye on the farther end of the platform.
2.4Nautical A piece of material or a knot used to indicate a depth on a sounding line.
2.5Telecommunications One of two possible states of a signal in certain systems.
2.6A level or stage that is considered significant.
unemployment had passed the two million mark - More example sentences
More example sentences - The day's only climb, a fourth category rise over the Cote de Boutancourt, comes early in the stage at the 8.5km mark.
The day's only climb, a fourth category rise over the Cote de Boutancourt, comes early in the stage at the 8.5km mark.
Richard Virenque takes the third climb at the halfway mark of the stage.
Today sales are steering towards the three-quarters of a million mark.
The million mark is actually quite an achievement.
Recent employment data showed the number of people over retirement age who are back in work has risen above the million mark for the first time.
Information technology has passed the million mark - and it's a statistic the sector is far from happy with.
The million mark for private cars was reached in Britain in 1930, with 10 million by 1967.
Botero was part of a group of seven which made a decisive break shortly after the 80 km mark of the stage.
With another busy five months to go, things are looking good for Cork Airport to pass the two million passenger mark for the first time.
This album, at worst, is going to take me over the 40 million quid mark.
Manchester Airport is back on course to break the 20 million passengers-a-year mark for the first time.
The trio made their initial attack at the 22 km mark and at one stage pulled out a 5m 20s advantage.
Who Wants to be a Millionaire did a little better but failed to top the million viewer mark.
This would see them hit the crucial five million mark.
Worldwide, estimates top the one trillion mark - almost two million a minute.
I did point out to the minion who rang me that come next spring we were likely to be in a position to have a balance somewhere around the quarter million mark.
Presumably she judged that once the death toll passed the quarter million mark, it became fair game for a bit of a snicker.
He began at one and he continues counting on a new canvas, beginning with the number he ended his last work on, reaching by now well past the five million mark.
We reached the mark of one million visitors just a few moments ago.
Hundreds of people are continuing to sign up each day to our petition to save Terry's, with the number of signatures now flying past the 3,000 mark.
2.7British A particular temperature level in a gas oven.
preheat the oven to Gas Mark 5 - More example sentences
More example sentences - Now tip the mix into the warm souffl dish and stick the result in an oven at gas mark six.
Now tip the mix into the warm souffl dish and stick the result in an oven at gas mark six.
3British A point awarded for a correct answer or for proficiency in an examination or competition.
many candidates lose marks because they don't read the questions carefully
More example sentences - full marks to them for highlighting the threat to the rainforest
full marks to them for highlighting the threat to the rainforest
There will be no marks awarded for the answer They both write historical fantasy.
It is possible to discourage guessing by allocating one mark for a correct answer and minus one for an incorrect answer.
Although the paper is 80 marks / answer all questions, there is some consolation in that several questions are perennial.
Make sure the answer sheet is stapled to your answer book or else you could lose a lot of marks if your answer sheet gets lost, he said.
It is surely also the case that some students lose a few marks here and there because of this.
Government proposals could mean pupils who can't spell lose marks in GCSE and A level exams.
Extra marks are awarded for neatness, good spelling and strict adherence to the curriculum.
I have to admit that Slovenia lost marks in my book for its food, despite the fact that it was much cheaper than in neighbouring Italy or Austria.
If fields, houses, gates, fences, derelict houses are untidy, then we lose marks.
The eleven marks were lost despite the village being cleaned up every morning of the week.
They got to a tie-breaker for third position, but were unfortunate to lose by a mark.
Students are awarded marks out of seven for each paper, and get a final overall score.
I know of a professor who was in the habit of deducting marks in examinations for bad spelling, poor grammar or clumsy sentences.
A lot of marks are lost because people misread the questions.
The villages provide the judges with a map and description of the area, and then they go around different sections giving marks out of 25.
For 45 marks, he was asked to write an essay of about 40 lines on the advantages of a cheerful disposition.
Again, students would write a report on completion of an assignment, marks being gained as before.
I sincerely hope I've done better than a U in French writing this time and I hope I've got enough marks in Chemistry so that I don't need to take any more exams for it in the summer.
You're not going to get negative marks for writing down something wrong, nor will marks be deducted from another question.
Stats and Maths papers were structured with 120 possible marks.
3.1A figure or letter representing the total number of marks awarded in an examination or competition and signifying a person's score.
the highest mark was 98 per cent - More example sentences
More example sentences - These are some of the terms used to describe children unable to learn or more importantly who score poor marks in their examinations.
These are some of the terms used to describe children unable to learn or more importantly who score poor marks in their examinations.
Researchers discovered that different academics gave different marks for the same essays.
The problems in the evaluation system is not limited to the disparity in marks between different universities.
A high-flying young Chorley scientist is focusing on a career path which could help save thousands of lives after receiving record marks in her degree.
Other Hampshire schools and colleges were toasting record marks.
We can all see that schooling has grown to mean exams, marks, stress, and tension for the parents, tuitions.
The modular approach to A-levels should, if anything, be extended but marks should be formally recorded for each module rather than hidden under an overall grade.
She usually stressed about her academic marks when she wasn't depressed and morbid.
Probably most interesting out of the whole debacle is the notion that science students can't get good marks if they can't write well.
In other words, essays attributed to children with popular names were given higher marks than essays purportedly written by children with unusual names.
I thought about taking it before exams, but then again, I never ever got good marks, when I wrote smart things, so I didn't.
At the University of Calgary, he hopped from fine arts in his first year to drama in his second, working hard to improve his marks and writing skills.
Last summer there were around 52,000 protests against A-level marks, of which about 10% resulted in an overall grade change.
This summer she received 4 grade As at A-level, achieving top marks in several papers.
A student gets to prepare his own report card, adding explanatory paragraphs that put the best possible spin on his marks.
This led to a broader approach to teaching programmes and abolished the link between Proficiency marks and secondary education.
He awarded marks ranging from six to ten, with his six favourites all receiving the ten mark.
This comprises writing comments for sight, colour, nose and palate of each drink, and then awarding a mark out of ten.
The continuing upward trend in results has prompted calls for the marks awarded to each exam to be published rather than a grade, so students' performances can be differentiated more easily.
At the end of the course of study, candidates receive a mark from one to seven in each subject.
3.2Horse Racing An official assessment of a horse's form, expressed as a figure between 0 and 140 and used as the basis for calculating the weight the horse has to carry in a race.
horses tend to run off a higher mark over fences than they would over hurdles
More example sentences - He has work to do off his revised handicap mark, but Medison never got the chance to show what he could do in two subsequent starts as he made a bad error at Aintree and was over the top for the campaign at Sandown.
He has work to do off his revised handicap mark, but Medison never got the chance to show what he could do in two subsequent starts as he made a bad error at Aintree and was over the top for the campaign at Sandown.
The William Haggas-trained gelding has progressed nicely this season and still looks to figure on a competitive handicap mark.
If their horse finishes anywhere near the good ones, his handicap mark will be ruined and he could go two seasons without winning another race.
Their stablemate War At Sea could be a bit better than his handicap mark suggests here.
Ettrick Water races off a mark just 2lb higher in the Scotland the Brand Scottish Trophy Stakes and he looks the one they all have to beat.
3.3(especially in athletics) a time or distance achieved by a competitor, especially one which represents a record or personal best.
he blasted away from the field during the second lap to knock a second off the existing mark
More example sentences - He also helped set three relay world records and lowered his own mark in the 400 freestyle.
He also helped set three relay world records and lowered his own mark in the 400 freestyle.
Thorpe is the current Olympic and triple world champion in the 400 meters and holds three world marks in freestyle distances.
In these she recorded marks of 12. 53s and 1. 51m to put her in an overall 14th place.
But her marks are in the record books and appear set to stay there for a good while longer yet.
She set a British under-20 indoor pentathlon record, bettering the marks of two who would become Olympic champions, Denise Lewis and Sally Gunnell.
Synonyms - required standard, standard, norm, par, level, criterion, gauge, yardstick, rule, measure, scale
required standard, standard, norm, par, level, criterion, gauge, yardstick, rule, measure, scale
a Mark 10 Jaguar - 5A target.
5A target. - few bullets could have missed their mark
few bullets could have missed their mark - She threw the last knife she was holding at the target in frustration, not hitting far off from the target mark.
She threw the last knife she was holding at the target in frustration, not hitting far off from the target mark.
This makes it difficult to say when a particular quatrain has missed or hits its mark.
As she develops she should be able to reach out and grab an object, even though she often misses the mark on the first try.
Someone attempting to be ironic: some points hit a mark, some are hateful and off target.
So far, the Democrats seem to have hit all their marks.
As for post-1947, Ganguly hits all the major marks of the conflict and lucidly backs his theories up with carefully researched facts.
When a History Channel doc makes you think, then the writers and researchers have done their job, they're hitting their marks as well as can be.
The writing is clever, witty, crisp, Arquette is very good, and the whole production is bright and hits all the right marks.
The emphasis on hitting your marks was not nearly as pronounced.
I'm always hitting marks, and saying the jokes, and having a good time.
As one arrow after the next misses its mark, all the boys immediately run for cover, but secret crushes soon rise to the surface.
These assaults, and their implicit criticism of the active VP, miss the mark.
I think his answer is - or I should say, proposal, if indeed we can call it that, misses the mark.
They may very well have this evidence, but everything that's being leaked right now is kind of missing the mark.
However, it seems to be missing the mark, and I'd argue it is because of the way we purchase music currently.
Someone's attempt at a clever analogy perhaps; it rather missed the mark.
Whichever way you look at it, the scheme was misconceived, miscalculated and entirely missed the mark.
She may miss the mark sometimes, but you've gotta applaud her sense of adventure.
And with hummable lyrics and soulful tunes, she seems to have hit the right mark once again.
This is where the current public policies around work-life balance seem to miss the mark.
5.1US informal A person who is easily deceived or taken advantage of.
More example sentences - they figure I'm an easy mark
they figure I'm an easy mark - She thereby revealed herself to be a patsy, a mark, a victim of the Big Con.
She thereby revealed herself to be a patsy, a mark, a victim of the Big Con.
The American salesman, everyone concedes, is the American salesman's easiest mark.
She actually felt sorry for her; Scott was the worst person to work with when there was a major mark on the line.
6Rugby The act of cleanly catching the ball direct from a kick, knock-on, or forward throw by an opponent, on or behind one's own 22-metre line, and exclaiming Mark, after which a free kick can be taken by the catcher.
Free kicks and marks could be required to be taken as kicks, as the name suggests.
More example sentences - This was followed by the referee then allowing a Tigers' player to interfere with Copeland taking a quick free-kick after a mark.
This was followed by the referee then allowing a Tigers' player to interfere with Copeland taking a quick free-kick after a mark.
Dropped marks in the forward line proved costly for the Bears and when the whistle blew to mark the end of the final quarter, Albatross had won 11-6.
6.1Australian Rules Football An act of catching a ball that has been kicked at least fifteen metres before it reaches the ground, or the spot from which the subsequent kick is taken.
More example sentences - David Loats takes a strong mark in the forward line in front of a few Eagles' defenders.
David Loats takes a strong mark in the forward line in front of a few Eagles' defenders.
verb - [with object]
[with object] - 1Make a visible impression or stain on.
1Make a visible impression or stain on. - he fingered the photograph gently, careful not to mark it
he fingered the photograph gently, careful not to mark it
More example sentences - They were faded, some stained by water from rain and a few marked by mud or beer.
They were faded, some stained by water from rain and a few marked by mud or beer.
Her gray dress was torn and dirty, marked more so by several spots of blood.
She turned a corner and stopped before colliding into a little boy, face marked with tears.
Around 10 flag stones, each around a metre square in size, had been taken from the site, leaving others broken and the steps marked and scratched.
I lingered on the bruise that marked most of his cheek.
As we walked, we passed from grass and mud to stone-paved road, wet and dirty and marked with wheel tracks.
Angie woke up to dried tears in her eyes and her face marked by the carpet since she remained there all night without moving to her actual bed.
The latter is clearly marked with close-spaced lines where it has pressed against the gills of the immature cap.
With a sharp instrument, mark the two holes indicated on the edge and the face of the door.
they're made from a woven surface which doesn't mark or tear
2Write a word or symbol on (an object) in order to give information.
she marked all her possessions with her name - More example sentences
More example sentences - an envelope marked private and confidential
an envelope marked private and confidential - They have placed it in a sealed envelope marked private and confidential.
They have placed it in a sealed envelope marked private and confidential.
Written references should always be marked private personal and confidential and should be sent in a sealed envelope by post or courier.
Anyone without a bank account can make a cash donation by placing it in an envelope marked Christmas Care and give it to reception at the Information Centre.
Seven columns in each ring have been marked with strange symbols, forming a huge seven-pointed star.
These days most of them have to go in blue and red envelopes marked Par Avion.
Any solution that only can be administered topically should be marked clearly with that information.
When all is said and done, this case file can be marked High School Confidential!
Synonyms - put one's name on, name, initial, put one's seal on, label, tag, hallmark, watermark, brand, stamp, earmark
put one's name on, name, initial, put one's seal on, label, tag, hallmark, watermark, brand, stamp, earmark
indicate, label, flag, tab, show the position of, show, identify, designate, delineate, denote
2.1Write or draw (a word, symbol, line, etc.) on an object.
she marked the date down on a card - More example sentences
More example sentences - He turned his wrist over and revealed a series of code symbols marked on his arm.
He turned his wrist over and revealed a series of code symbols marked on his arm.
3Indicate the position of. - the top of the pass marks the border between Alaska and the Yukon
the top of the pass marks the border between Alaska and the Yukon
More example sentences - we have marked the area with red stones
we have marked the area with red stones - We moored to the buoy that marks the Haven's position, and Gino put the decompression station in place.
We moored to the buoy that marks the Haven's position, and Gino put the decompression station in place.
The position of each station will be marked by a cross.
Two large stones also stand almost due east and west to mark the local equinoctial positions of the sun.
It has marked the dividing line between North and South Korea ever since.
The lamp, which would originally have been a gas lamp, marked a dividing line in the town.
The two people in question were driving their car out to Coney Island when they veered off the line of concrete markers which marks the route.
In one part of the complex, crosses mark an area which has been designated as a graveyard.
Under an azure sky at Almondvale, horizontal trenches marked the areas where undersoil heating was being installed.
These sills mark areas at the coast where low relief makes it possible for a glacier to spread out and thus lose its erosional power.
Gaps themselves mark the areas of vulnerability and show the mechanism by which complexity flows through health care to individual patients.
Synonyms - put one's name on, name, initial, put one's seal on, label, tag, hallmark, watermark, brand, stamp, earmark
put one's name on, name, initial, put one's seal on, label, tag, hallmark, watermark, brand, stamp, earmark
3.1(of a particular quality or feature) distinguish (someone or something) from other people or things.
his brand of theatrical pop has marked him as one of modern music 's most innovative talents
More example sentences - Good distribution allied with his pace and defensive qualities mark him out as a fine prospect.
Good distribution allied with his pace and defensive qualities mark him out as a fine prospect.
It doesn't make you part of a family, hanging out in the Apple store marks you out as a computer geek, not a trendsetter.
Synonyms - set apart, separate, single out, differentiate, distinguish
set apart, separate, single out, differentiate, distinguish
3.2Acknowledge or celebrate (an important event) with a particular action.
to mark its fiftieth birthday the charity held a fashion show
More example sentences - Plans are being formulated to hold a celebration event to mark the 10th anniversary of the club next April.
Plans are being formulated to hold a celebration event to mark the 10th anniversary of the club next April.
This ceremony is supposed to mark an important event in the life of the eunuchs, when they realise their dream of marrying for once.
It was the highlight of a series of events held last week to mark the beginning of six months of celebrations to marks the Quakers' important anniversary.
Graduation from high school and from college are seen as important events that mark the beginning of adulthood.
I'll ask him why he's boycotting tomorrow's anniversary celebration in Moscow marking the end of World War Two.
It was all of 21 years since the team had won the Mayo and Connacht honours and some members felt the time to hold a celebration to mark the event.
Celebrations to mark the big event were on a grand scale and went on for three nights.
This ritual together with tonight's celebrations are all that mark an event which has now become pretty meaningless to British society.
The good weather added to the spectacle and everyone involved should be very proud of the celebrations to mark the Feast Day of our Patron Saint.
The celebrations marking the 60th anniversary of the event have been unprecedented in scope.
And when they came to the end of their trek their achievement was marked with celebrations.
Four generations of the Salt family gathered in a building constructed by their ancestor to mark a festival celebrating Sir Titus Salt.
A church celebrating its 50th anniversary is to mark the occasion with two special events.
The event also marked the beginning of Pattaya's St. Valentine's Day celebrations.
The bravery and resourcefulness of British prisoners of war will be celebrated in an exhibition marking the 60th anniversary of the Great Escape.
Friends of Reuben was formed last February 23 and they will hold a celebration to mark its achievements on its first anniversary next week.
The celebrations marking the end of the Great Patriotic War are underway in Moscow.
The finished design marks the 400th anniversary of the 1605 gunpowder plot, led by infamous York son Guy Fawkes.
The week beginning July 8 would be marked by a flag ceremony.
A presentation was made to both earlier this year to mark the 50th anniversary of their position.
Synonyms - celebrate, observe, recognize, acknowledge, keep, honour, solemnize, pay tribute to, salute, commemorate, remember, memorialize
celebrate, observe, recognize, acknowledge, keep, honour, solemnize, pay tribute to, salute, commemorate, remember, memorialize
3.3Be an indication of (a significant event or stage)
the incidents marked a new phase in the terrorist campaign
More example sentences - the move to the new Globe theatre marked a new phase in Shakespeares writing career
the move to the new Globe theatre marked a new phase in Shakespeares writing career
The stage victory marked a reversal of fortunes for the 26-year-old who lost the prologue when his chain came off close to the finish.
Because the unit can be traced over several tens of kilometres, we suggest it marks a sub-regionally significant event in the Emeishan Province as basalt production terminated.
Ms McGreal said the event marked the end of the talking phase for women in agriculture.
If the Erskine scheme comes to pass, it will mark a significant change in fortunes for similar proposals.
The legislation marks a significant change in US policy and means that food aid can be used directly as a weapon of war.
The 1930s marked a significant change in the Soviet approach to retail trade.
This event marked the start of the defeat of the reform movement.
The move marked a significant change in US policy and means that food aid can be used directly for military purposes.
That event surely marked the end of the world as we have known it.
This marks a significant increase on previous years, with some very serious incidents requiring hospitalisation.
Sleep researchers generally agree that Stage 1 marks the transition from waking to sleeping states.
Hartstein's decision marks a significant change in the direction of the company.
This event marked the humble beginning of what would become the US Air Force.
The Japanese responded at once, and these events marked the true beginning of the Sino-Japanese war.
This event marked a downfall of popularity for the hot air balloon, and an increase in popularity, ironically, in hydrogen.
This event marked a major change in the temper of the civil rights movement.
There are some defining events in the life of a nation - events that mark a major change of direction.
For me, this event clearly marks the end of the happy, carefree years of my childhood.
While the figure was down on that for March, lending was 16% higher than in April 2005 and marks six months of record lending figures.
The Supreme Court opens today, marking our full judicial independence from Britain.
Synonyms - represent, signify, be an indication of, be a sign of, indicate, herald
represent, signify, be an indication of, be a sign of, indicate, herald
3.4usually be marked byBe a noteworthy quality or feature of.
the reaction to these developments has been marked by a note of hysteria
More example sentences - Sargent's work is marked by its exceptional lucidity, its exactness of expression and by the decisiveness of her results.
Sargent's work is marked by its exceptional lucidity, its exactness of expression and by the decisiveness of her results.
Clough's early works are marked by a subdued palette of largely browns, greys and greens.
His subsequent work was marked by an offbeat intensity.
In every case his works are marked by a high level of technical skill and surfaces of great animation.
Dwelling as they did in clusters of local self-sufficiency, marked by a low standard of living, the people were ever threatened by famine.
The media had under-rated his dad, Barry felt, and his career has been marked by a ruthless determination to correct that historical injustice.
Some critics discerned a falling away of powers in his later work, marked by a tendency towards inflated rhetoric, but to others he remained a commanding figure to the end.
So what does 2000 offer the mid-market fashion retail sector after another bleak Christmas marked by early sales notices?
Above all, he prepared mounts that were marked by meticulous attention to detail and precise labeling.
Seemingly interminable rallies are marked by players pounding the ball at one another in games that go hours at a time.
Her career had been marked by close defeats and valiant efforts.
A quarterback's first season with a team is almost always marked by struggles fitting in with his new offense.
Both rider and vet would have been conscious of the risks they were taking so close to a games that was marked by a hunt for drug cheats.
Paddle is largely a doubles game, marked by rapid volleying at the net.
But apart from a few minor concessions, her term in office has been marked by close collaboration with business.
From lack of talent to utter indiscipline, the team has suffered on many fronts and the slide has been marked by a shocking indifference among the players.
3.5British (of a clock or watch) show (a certain time)
his watch marked five past eight - More example sentences
More example sentences - The next cut finds him waiting for the second hand on the clock to mark 5.00 pm and thus the banal end to his career.
The next cut finds him waiting for the second hand on the clock to mark 5.00 pm and thus the banal end to his career.
Sure enough, as the clock marked 8.30 am, Neptune's special police arrived on the Bridge.
4British (of a teacher or examiner) assess the standard of (written work) by assigning points for proficiency or correct answers.
the examiner may have hundreds of scripts to mark
More example sentences - Work has been set for him and as far as I'm concerned it's being marked by teachers.
Work has been set for him and as far as I'm concerned it's being marked by teachers.
She says the programme involved properly supported unit standards marked by trained teachers and assessed to the standard.
It also says the initial measurement for seven-year-olds is unreliable as it is marked by teachers rather than external examiners.
She suffered a series of literary knockbacks until her work was marked by an external examiner during a creative writing course.
One was assessing the candidate's driving, while the other was assessing the examiner's marking.
The exam papers were marked by teachers and then sent to external moderators.
Exams in Scotland are supervised by non-teachers but the papers are marked by teachers.
He felt that having to sit and write an essay that the teacher would mark so that another tick could be put in another box was a waste of time and time was a precious commodity.
We were encouraged to mark our own work by referring to the answer books that were always readily available.
The establishment will be marking their assignments, writing their job references, and checking their credit ratings.
It needs to be well lit, warm, not too noisy and have a table - work is often marked for neatness and a steady surface helps with writing and drawing.
It's a very good point, which is why more and more academic work is marked by continuous assessment.
The examiner then marked it and explained why he had given the marks he had.
Next September teachers will be guaranteed time to plan, prepare and mark work as part of a national deal.
By the time I've finished seeing students, marking their work, preparing classes, doing the admin etc. etc. that more than doubles.
Without a tutor to mark your work, how will you know if you got it right?
Miss Piper began to call out the answers as the whole class followed and marked their own work.
Throughout each term homework was set by the subject teacher to a timetable and at the end of term an exam was also set and marked by the same teacher.
At 15 per child, the mock will be fully supervised under exam conditions and papers will be marked anonymously.
They were not the ones who did first year Geo-morphology at nine o'clock on a Monday morning, or marked a hundred scripts in two days.
Marin didn't seem to notice, marking something on the paper in front of him.
Synonyms - take heed of, pay heed to, heed, listen to, take note of, take notice of, pay attention to, attend to, note, mind, bear in mind, give thought to, give a thought to, take into consideration, take to heart
take heed of, pay heed to, heed, listen to, take note of, take notice of, pay attention to, attend to, note, mind, bear in mind, give thought to, give a thought to, take into consideration, take to heart
6British (of a player in a team game) stay close to (an opponent) in order to prevent them getting or passing the ball.
each central defender marks one attacker - More example sentences
More example sentences - Harrogate were camped in their half for the entire game and despite marking Elliot Dowley ferociously were not able to match his pace and he put away a winner in the nick of time.
Harrogate were camped in their half for the entire game and despite marking Elliot Dowley ferociously were not able to match his pace and he put away a winner in the nick of time.
If he is assigned a player to mark throughout a game, it is almost guaranteed that that player will not have a large impact on the game.
Lorraine Pugh had her best performance in the game against Glynn as she was marking their best player Anne-Marie Moloney.
That means that the full-backs are tied, and the three central defenders are marking one striker.
Silsden eventually came into the game but their front men, Hoyle and Hedges were tightly marked throughout the game and had to play much of the time with their backs to goal.
Players are marking better now than they have been since the seventies.
Since he would be closely marked by the opponents, other strikers would get more open space to play.
Meanwhile, Is it too late to add Shaquille O'Neal to the squad to mark Koller?
6.1Australian Rules Football Catch (the ball) from a kick of at least ten metres.
I did well at marking the ball - More example sentences
More example sentences - Opening 52 Seconds: Bombers win the ball from the opening bounce and Lucas marks at centre half forward.
Opening 52 Seconds: Bombers win the ball from the opening bounce and Lucas marks at centre half forward.
But in fact, it makes it almost impossible to see which player is marking the ball, as other players swarm around you.
Phrases - close to the mark
close to the mark - Almost accurate.
Almost accurate. - according to him, $10 billion is closer to the mark
according to him, $10 billion is closer to the mark
More example sentences - to say he was their legal adviser would be nearer the mark
to say he was their legal adviser would be nearer the mark
Mr Sheridan said claims indicate their initial estimates that close to 4m will be required to compensate investors will be very close to the mark.
Although descriptions of Clarke as the next Waugh appeared trite, they are starting to look eerily close to the mark.
Caddell is not alone among the anti-Bush who acknowledge that some Bush attacks are uncomfortably close to the mark.
The anti-Communist series is still pretty close to the mark.
Well, today's New York Times adds some new information that makes it look like Clinton was pretty close to the mark.
My Landlord was fine about it surprisingly - which makes me think my earlier suspicion of him wanting us all out anyhow is close to the mark.
This is an overly simplified explanation, but very close to the mark nonetheless.
What these numbskulls in power call Christianity doesn't even come close to the mark.
Even allowing for a little poetic license, this statement is perhaps close to the mark.
That is putting it pretty strongly, and there are admirable exceptions, but it is embarrassingly close to the mark.
on your marks - Used to instruct competitors in a race to prepare themselves in the correct starting position.
Used to instruct competitors in a race to prepare themselves in the correct starting position.
1A long way from an intended target. - More example sentences
More example sentences - most of his shots went wide of the mark
most of his shots went wide of the mark
past demographic projections have been way off the mark
More example sentences - The Atkins diet may turn out to be completely off the mark, but it shouldn't be dismissed yet.
The Atkins diet may turn out to be completely off the mark, but it shouldn't be dismissed yet.
The analogy with a Chelsea footballer or a classical pianist is completely off the mark.
Readers are welcome to put me in my place and show me that I'm completely off the mark!
It appears that the invasion scares promoted by publications over the last few years were not completely off the mark.
When the US State Department issued its damning report, again he was late and off the mark.
He was disturbed himself at the result of a report that was so far off the mark.
I think claims that there's too much oil out there today are just simply off the mark.
But in seeing such engagements as determining our future development, they are way off the mark.
He also indulged in a bit of illicit breaking and entering, but most true professionals reckon he was way off the mark.
on the mark - Correct; accurate.
Correct; accurate. - his forecast for the weekend is right on the mark
his forecast for the weekend is right on the mark
More example sentences - That said, I voted for John Edwards because I'm a bit of a contrarian and because I think he's on the mark when he talks about two Americas.
That said, I voted for John Edwards because I'm a bit of a contrarian and because I think he's on the mark when he talks about two Americas.
In a call for appropriate content for an audience, it sounds like this is on the mark.
I'd check back occasionally, and Jonas would always be on the mark with whatever analysis or discussion he was having.
Some of these items are trivial or irrelevant, but many are on the mark.
He is certainly on the mark with such judgments, but he might have made them with more humor and less earnestness.
Obviously, only one of the myriad of warnings he received throughout his four years in office was on the mark.
Am I on the mark in thinking of you as mainly a political stirrer?
Your comments on illegal immigration were right on the mark and very brave.
But his political analysis was on the mark, even if he falls short of the presidency.
Stalin was on the mark in saying that one death is a milestone, a million is a statistic.
make one's mark - Attain recognition or distinction.
Attain recognition or distinction. - it took four years of struggle before we managed to make our mark
it took four years of struggle before we managed to make our mark
More example sentences - The BBC will televise the second day of competition, and Brewer underlined the importance of new prospects making their mark if financial patronage is to be restored.
The BBC will televise the second day of competition, and Brewer underlined the importance of new prospects making their mark if financial patronage is to be restored.
That women entrepreneurs and managers are making their mark in a world of men, even if recognition comes by way of separate women's awards.
First, his distinction is quite exceptional and we don't have to wait for it to be generally recognized that he has made his mark.
In 1989, she was trying to make her mark as a singer in London but had succeeded only in eking out a living, playing tiny gigs and taking the odd bit-part acting job.
Professionally, the 21-year-old Long Island native is already making her mark as one of the most distinctive character actors of her generation.
It gives the illusion of doing something permanent, making your mark on the world.
It is about the thousands of highly-qualified young people making their mark in responsible jobs in Germany, France, Netherlands, Belgium and elsewhere across the EU.
I am not quite sure who to propose, but maybe there is someone out there who feels confident enough to list 10 women in contemporary graphic design currently making their mark.
In the ten years of this sale close on 3,000 heifers have been sold and it is evident by the number of repeat buyers that these heifers are clearly making their mark in the suckler herds of Ireland.
The range of soloists offers a blend of the experience of established performers for many years with the talent of some our finest young musicians who are now making their mark here and abroad.
get off the mark British - Get started.
Get started. - he took an hour to get off the mark but finished with 101 runs
he took an hour to get off the mark but finished with 101 runs
More example sentences - He will be approaching national companies in a bid to get some high-profile backing and has already got off the mark by selling his first perimeter board advert in his first week.
He will be approaching national companies in a bid to get some high-profile backing and has already got off the mark by selling his first perimeter board advert in his first week.
be slow off the mark British - Be slow in responding to a situation or understanding something.
Be slow in responding to a situation or understanding something.
More example sentences - clearing trucks were slow off the mark, leaving angry shopkeepers to shovel their pavements
clearing trucks were slow off the mark, leaving angry shopkeepers to shovel their pavements
mark you British - Used to emphasize a statement.
Used to emphasize a statement. - I was persuaded, against my better judgement, mark you, to vote for him
I was persuaded, against my better judgement, mark you, to vote for him
More example sentences - This statement, mark you, is made by a man who is described at the foot of the article as the Washington Post's book critic.
This statement, mark you, is made by a man who is described at the foot of the article as the Washington Post's book critic.
I suppose if I were to take a full time teaching post then I could have a nice hefty mortgage and afford a house of decent proportions not on the salary, mark you, but on the combination of salary and equity from this house.
Yet we expect officials to train themselves, prepare themselves and make the important decisions week in and week out for #310 a game - and that, mark you, is for the top referees.
Hitchens's article takes the form of a review of The John Hopkins Guide to Literary Theory and Criticism; in its second edition, mark you, so the thing must be a really hot seller.
This, mark you, was his opinion at a time when the number of books published in the UK in a year was somewhere around 10% of today's figure.
And this, mark you, in a business which is largely based in London.
Not, mark you, setting out to prove there is none, but determined to prove that there is.
And all this, mark you, before a date for the general election has even been set.
These are the same people, mark you, that would have bought every single song they downloaded if the alternative was to go without - according the the recording industry's claims for the impact of downloading, that is.
This, mark you, is my first interview in six months.
of mark dated - Having importance or distinction.
Having importance or distinction. - he had been a man of mark
he had been a man of mark - More example sentences
More example sentences - In 1607 he was apprenticed to his uncle Sir William Herrick, goldsmith, a man of mark who was MP for Leicester, owned land in 13 counties, and had been knighted in 1605.
In 1607 he was apprenticed to his uncle Sir William Herrick, goldsmith, a man of mark who was MP for Leicester, owned land in 13 counties, and had been knighted in 1605.
There was also the prospect of becoming a man of mark back home when the volunteer's term was up.
be quick off the mark British - Be fast in responding to a situation or understanding something.
Be fast in responding to a situation or understanding something.
he was quick off the mark with girls - More example sentences
More example sentences - Police were quick off the mark and they were here really fast.
Police were quick off the mark and they were here really fast.
The Left has been slow off the mark in identifying the obvious American responsibility for that event.
Ford, too, has been slow off the mark but is catching up fast after it recently licensed hybrid technology from Toyota, while also giving a bit of its own technology back.
The city's snow - clearing trucks were slow off the mark, leaving angry shopkeepers to shovel their pavements.
Some filling stations in Galway were quick off the mark on Budget night when they immediately at 12 midnight increased the price as stipulated in the Budget.
Although Banbridge were quick off the mark with their scoring, the Burren boys were just as quick to get back into the game and soon took control for the remainder of the match.
Of course being the day that it was, local papers were quick off the mark and Serena was asked to sign a consent form so that the hospital could give details of the birth to the press.
They'll be glad they were quick off the mark because the practice has now been stopped by the director of New York's office of emergency management.
So, as soon as he made a serious gaffe - as he did - they were quick off the mark to call for his ouster.
mark time - 1(of troops) march on the spot without moving forward.
1(of troops) march on the spot without moving forward.
I had them mark time and started them off marching down the trail that led to the football field.
More example sentences - He blew his whistle, signaling for the band to mark time.
He blew his whistle, signaling for the band to mark time.
Still, some steps are better than just marking time in place, right?
1.1Pass one's time in routine activities until a more interesting opportunity presents itself.
we're all just marking time, waiting for Wednesday
More example sentences - But he's only marking time until he can return to New Orleans.
But he's only marking time until he can return to New Orleans.
In the short term the markets are still nervous and will mark time until the outlook for the US becomes more certain.
The secondary has to find out and the kids with a high-level D have to mark time until those without catch up.
It was as if they just wanted to mark time until the final whistle and take the win.
The response confirmed to him that the crowd was enjoying what the augmented DJs were doing and there was no sense that everyone was just marking time until the headliners came on.
Do you love what you're doing or are you just marking time until that record deal goes through?
It's also probably bad news for developers, because they'll have to mark time until whenever early is.
At her worst, Gilda comes off as a whinier Lucille Ball, and we mark time until the next skit.
Black can't improve his position so he marks time.
I would mark time during ballet, jazz, and acrobatics and wait for tap, she says.
leave one's mark - Have a lasting or significant effect.
Have a lasting or significant effect. - he left his mark on English football
he left his mark on English football - More example sentences
More example sentences - He penned pamphlets of protest, left his mark on Philadelphia's most significant free black institutions, and produced a moving spiritual autobiography.
He penned pamphlets of protest, left his mark on Philadelphia's most significant free black institutions, and produced a moving spiritual autobiography.
Not all of us will get to do that, but you can with the self-assurance that you have indeed left your mark.
Today's Indian cuisine is certainly not exactly what it was thousands of years ago as invasions, migrations and travel have left their mark on the sub-continent.
We must never forget the day when the terrorists left their mark of murder on our nation.
It wasn't a game for cowards, as some bone-crunching hits, and a mass brawl in a bad-tempered first-half, left their mark physically on both sets of players.
Here are the three affairs that truly left their mark in history.
Incursions into the country, successively by the Persians, Byzantines, Mongols and Turks are all said to have left their mark on the cuisine.
During the Cold War, it was the Russians who left their mark.
Few people have so left their mark upon the world.
The riots of a year ago, have however, left their mark.
up to the mark - 1British Up to the required standard.
1British Up to the required standard. - concern has been growing that economic forecasts are not up to the mark
concern has been growing that economic forecasts are not up to the mark
More example sentences - He held several senior positions at the infirmary, notably chairman of a committee which makes sure clinical standards are up to the mark.
He held several senior positions at the infirmary, notably chairman of a committee which makes sure clinical standards are up to the mark.
Good firms tend to have demanding customers, which stands to reason: picky customers keep you up to the mark by requiring value for money and telling you if you don't give it.
Even so, the TV audio quality was not up to the mark.
If quality was not up to the mark, it was taken away.
About half the Irish food businesses applying for a hygiene excellence scheme are not up to the mark.
However, with mediapersons carrying video and digital cameras, the quality of transmission was not up to the mark.
It provides full wireless connectivity, easy synchronization with other wireless devices, high performance, up to the mark video and audio quality.
So, yes, the DVD content is well worth your attention, but is Artisan's presentation up to the mark?
Inadequacy in bowling was another, the side's batting was not up to the mark and the team did not possess a quality all-rounder either.
Quality of the recording was not up to the mark as well.
1.1usually with negative (of a person) as healthy or as cheerful as usual.
More example sentences - Johnny's not feeling up to the mark at the moment
Johnny's not feeling up to the mark at the moment
Something which is particularly typical of or suitable for someone.
More example sentences - I took you out. To a motel! That's just about your mark!
I took you out. To a motel! That's just about your mark!
Phrasal Verbs - mark off
mark off - 1mark something off, mark off somethingPut a line by or through something written or printed to indicate that it has passed or been dealt with.
1mark something off, mark off somethingPut a line by or through something written or printed to indicate that it has passed or been dealt with.
he marked off their names in a ledger - More example sentences
More example sentences - As we laboriously went through each box, we marked them off in our spreadsheet.
As we laboriously went through each box, we marked them off in our spreadsheet.
We'd mark them off on a sheet displayed proudly on the refrigerator, until the sheet was filled and we'd read the required number of books to win the prize. I don't remember now what any of the prizes were.
The child marks the item off the list with help from his/her mother.
As soon as they had all settled themselves well enough in it, the teacher began taking their names and marking them off on a list he had on a clipboard.
There she refers to a friend who refuses to believe that committee work is just about marking items off an agenda.
I hadn't exactly been marking the days off between meetings but occasionally his handsome face had flitted through my thoughts.
The receptionist looked them up and marked them off as present.
To pass the time he began to count, telling each one to lay down as he marked them off.
She unconsciously marked each day off on her desk calendar in her office.
He simply took the little blue tardy notice and marked something off on his clip board.
The homeroom instructor, however, simply shrugged and marked her off.
Or you might keep a checklist of all your nighttime and morning tasks and have family members mark them off as each one is completed.
In fact, you can rip up the ballot if you want - all you need to do is go to the polling booth on election day and mark your name off the register.
Make lists (daily/weekly) and mark things off as they're accomplished.
2mark something off, mark off somethingSeparate or delineate a particular section or area.
More example sentences - cones marked off the excluded areas
cones marked off the excluded areas - 2.1(of a particular quality or feature) distinguish someone or something from other people or things of the same type.
2.1(of a particular quality or feature) distinguish someone or something from other people or things of the same type.
each of London's districts possessed an individuality that marked it off from its neighbours
More example sentences - what marked him off from other naturalists was his theory about the causes of evolution
what marked him off from other naturalists was his theory about the causes of evolution
mark up - 1mark something up, mark up something(of a retailer) add a certain amount to the cost of goods to cover overhead and profit.
1mark something up, mark up something(of a retailer) add a certain amount to the cost of goods to cover overhead and profit.
More example sentences - he marks up prized garments by at least 50 per cent
he marks up prized garments by at least 50 per cent
2mark something up, mark up somethingAnnotate or correct text for printing, keying, or typesetting.
they retyped the articles after the subeditors had marked them up in pencil
More example sentences - These files would be mostly text files, but they would be marked up with a tag language (a subset of SGML called Hypertext Markup language, or HTML).
These files would be mostly text files, but they would be marked up with a tag language (a subset of SGML called Hypertext Markup language, or HTML).
In the mid '70s, I got involved on the tail end of a really sexy project in publishing, creating a system that allowed editors to take text and mark it up on screen.
I had remembered to bring my copy, but I had already marked it up with all the comments I was going to make during the talk.
By the time the copy editor got back, marked it up, and sent it down to the subs, it was 10 pm.
I can make the addresses and so on machine readable, I just need to know how to mark them up.
The contents of the file can be marked up, such as adding color around words.
In addition, a copy of the draft lease was marked up with the proposed changes and returned to the hotel.
If you needed a brochure, you'd type it on a typewriter, and then literally mark it up with a red pen to tell the typesetter what you wanted it to look like.
I was not in a position to mark it up or to start working on it because I had to check it for correctness.
This new capability will eliminate the need to communicate changes by printing out a copy, marking it up, and faxing it back.
Everyone works with a single document, marking it up with their personal highlighting, notes, and edits.
And he would put in time reading your stuff and marking it up and making comments on it and so on, which was very useful.
Previously, Eminent sent 150-to 500-page study-protocol documents to participating physicians and regulators, who marked them up and mailed them back.
mark out - 1mark something out, mark out somethingSeparate or delineate a particular section or area.
1mark something out, mark out somethingSeparate or delineate a particular section or area.
More example sentences - you need to mark out the part of the garden where the sun lingers longest
you need to mark out the part of the garden where the sun lingers longest
2mark someone or something out, mark out someone or somethingBritish (of a particular quality or feature) distinguish someone or something.
his sword marked him out as an officer - More example sentences
More example sentences - her outstanding ability marked her out for rapid promotione
her outstanding ability marked her out for rapid promotione
mark down - 1mark something down, mark down something(of a retailer) reduce the indicated price of an item.
1mark something down, mark down something(of a retailer) reduce the indicated price of an item.
ties are marked down by at least 25 per cent
More example sentences - It has also led to spot shortages of fuel in the economically busiest areas of China, according to the China Securities News, with black-market speculators marking prices up 30% above levels set by the state-controlled pricing system.
It has also led to spot shortages of fuel in the economically busiest areas of China, according to the China Securities News, with black-market speculators marking prices up 30% above levels set by the state-controlled pricing system.
All I am getting is a couple more horrible sweets and they have clearly factored such thefts into their prices and marked them up by about 10,000%.
The price of blatberries had been marked down again at Mumlat's Market.
If a broker sells a municipal bond to a customer from the firm's own portfolio, for example, he or she need not tell the customer how much its price was marked up.
Anyway, prices were marked down to fifty, even seventy percent, and I got carried away and bought stuff, too.
But remember the old rule, he who shops best haggles the most, so just bargain till the prices are marked down to suit your budget.
Meanwhile, in America, we just put water in bottles with shiny stamps, mark the price up a thousand percent or more, advertise the hell out of the product, and consumers guzzle it down.
Steel prices had been marked up by a handful of producers in view of the rising exports to China and a few other countries.
Police opened the investigation following reports from several employees who said that the land price had been marked up to conceal the presence of the remaining funds.
I later notice that it has been marked down several times, indicating that nobody in this whole community knows what a Frette sheet is.
If the suit does not fit perfectly, do not buy it, even if it is marked down for a large discount.
The regular price was $180 and they were marked down to $49.
That was probably a $10 bottle of wine and they marked it up $30.
A survey by the Daily Mail revealed that apples in the superstores were marked up by as much as 198 per cent, while eggs commanded prices up to 439 per cent higher than were paid to the farmers.
In addition to what Tom says, purely observationally, you walk into Iceland or a variety of other shops and there are always two for one deals on freezer food while fresh vegetables are marked up.
However, staff predicted that the rush would start on Christmas Eve when a number of selected items would be marked down for their sale.
Bargain-hunters head downstairs to Filene's Basement, where items are marked down by 25% after 14 days, 50% after 21 days and 75% after 28 days.
2mark someone or something down, mark down someone or somethingBritish (of a teacher or examiner) reduce the number of marks awarded to a person or their work.
teachers marked down work containing poor grammar - More example sentences
More example sentences - I was marked down for having skipped the last essay question
I was marked down for having skipped the last essay question
In addition, Mid Yorkshire was marked down for not ensuring at least 98 per cent of patients with suspected cancer were seen within two weeks.
Like the Queen Elizabeth Hospital, Lewisham has been marked down for missing its four-hour A&E waiting time target for 2004 / 5.
A Merit would suffice, heck even a Pass would do as I know she's going to mark me down anyway because I slacked big time on the photography bit, but that was a different unit.
Then he was marked down again for the shocking shiny suit he was wearing and ended up without very much going for him at all.
Upon hearing that he had been marked down for wandering, Levrone fumed, I didn't know you could be marked down for walking offstage.
Asked why she felt she was marked down by the judges, she said: You better ask them.
Appraisal time is upon us, and all team leaders will have been instructed to find the slightest excuse to mark people down.
Even when made aware of bullying, Ofsted inspectors won't mark a school down for it now, either.
3mark someone down as something, mark down someone as somethingJudge someone to be a particular type of person.
she had marked him down as a dangerous liberal
More example sentences - In the reviews section, the very similar Joss Stone is marked down as an artist in it for the long haul.
In the reviews section, the very similar Joss Stone is marked down as an artist in it for the long haul.
An old school report marked Clary down as languid and superior.
Whatever else happens at these world championships, Paris will be marked down as notable the moment that Haile Gebrselassie toes the start-line for the 10,000-metres final in the Stade de France tonight.
Despite her lack of years and inches, Wood has been marked down as the Next Big Thing in Scottish curling for several years.
Collapsing with a fit of the jitters, she was marked down as a choker, not to be bothered with.
I gave my usual response, which is to smile politely and shake my head in an I-dooon't-think-so kinda way, whilst wondering, since I wasn't smoking at the time, how she'd marked me down as a smoker.
The police obviously marked me down as a criminal because next time I was at a French auction I was surrounded by gun-toting gendarmes who arrested me again.
Confounding those who had marked him down as a Eurosceptic, he declared: I believe in Europe as a political project.
If that's being a do-gooder, then mark me down as a proud one.
He may know nothing about Rangers, but they will already know enough about him to mark him down as a serious threat.
Cohen has little time for these critics, marking them down as unable to appreciate what Churchill's leadership really meant and too ready to discount the value of his ability to inspire and take charge.
Even if it helps me in the hunt, I don't like someone marking me down as an easy target, especially when he's wearing a bullseye himself and doesn't know it.
I hated playing musical scales and those stupid nursery rhymes set to music that piano students had to play, but I guess Dad marked me down as a loser in music, too.
The promoter, who also officiates on the junior grasstrack scene, spotted Complin several years ago and marked him down as one for the future.
The Austrian authorities soon marked him down as a troublemaker as he encouraged trade unions and attacked the Catholic Church.
She says she has no idea why the officer marked her down as owner being same as driver.
They were both dressed so that it was easy to mark them down as gypsy kin, their faded but bright clothes easy to spot amongst the normal gray drab of the peasants.
I look forward to a time when I can serve my country without wondering if history will mark me down as a participant in something disgraceful.
If this sort of scheduling - off days in mid-series and two-game series - is the result of Interleague Play, then mark me down as a baseball purist.
He was no longer just a gifted midfield player at the biggest club in the land - he was marked down as a player of immense potential, one on whom much of the international team's future success could be fashioned and shaped.
Origin - Old English mearc, gemerce (noun), mearcian (verb), of Germanic origin; from an Indo-European root shared by Latin margo margin.
Old English mearc, gemerce (noun), mearcian (verb), of Germanic origin; from an Indo-European root shared by Latin margo margin.
Main meanings of mark in English - mark2
mark2 - Pronunciation /mk/
Pronunciation /mk/ - noun
noun - 1(until the introduction of the euro in 2002) the basic monetary unit of Germany, equal to 100 pfennig; a Deutschmark.
1(until the introduction of the euro in 2002) the basic monetary unit of Germany, equal to 100 pfennig; a Deutschmark.
Germany spent billions of marks to save the French franc from speculators
More example sentences - Moreover, the budget was burdened annually to the tune of over 10 billion German marks by the war against the Kurds.
Moreover, the budget was burdened annually to the tune of over 10 billion German marks by the war against the Kurds.
Some 7.5 billion of German marks are frozen in state banks.
This in turn is equal to 1.95583 German marks, or 6.55957 French francs, or 166.386 Spanish pesetas, and so on.
The avowed aim of the Treasury is to reduce new debt from the present 50 billion German marks to zero by the year 2006.
A billion marks are to be saved annually through the sale of equipment, vehicles, land and buildings.
The German mark was introduced as a parallel currency to the Yugoslav dinar and then the euro.
The euro, which replaces the old francs, marks, guilders, pesetas, escudos, drachmas, and lire of the European Union, is not yet five years old.
Now that protection from future legal actions is in place, the 1.8 billion marks still missing from German business will probably trickle in.
Two billion German marks have been invested in the area's shipbuilding but the figures still show South Korea forging ahead.
The plan aims to implement cuts of 30 billion German marks, about 50 percent of which is to be raised by attacks on pensioners and unemployed.
The resort obviously is geared for the overseas market and while prices won't make a huge dent in sterling, marks, euros or yen, in rand terms they might appear expensive.
One of the reasons is that there were three different currencies in use in Germany during the war - the thaler, the mark and the gulden.
In the same survey, of 100 goods that were checked, an incredible 86 per cent of them had increased in price when moving from marks to euros.
That means the debt is likely to rise to 80 billion marks It's way too high.
Some 1 billion marks will be used to build a plant for the manufacture of synthetic materials in Shanghai.
She lived through the terrible poverty of the Weimar years, when the price of a loaf of bread soared to more than 50 million marks.
Thankfully, for 5.3 million marks, you can buy a hell of a lot of visual thunder, which is why you should see this movie in the first place.
When he called the next day, he said he was faxing Leeds an offer of a million marks.
Braeutigam called on lawyers to forego part of their 125 million marks in fees to help pay the additional compensation.
Brahms continued to mobilise support for him, and himself paid him an allowance of some thousand marks a year, while doing his best to remain an anonymous donor.
2A former English and Scottish money of account, equal to thirteen shillings and four pence in the currency of the day.
Sir William left 500 marks for repairing the road to Cambridge
More example sentences - Mrs Burdett was to be paid in marks, which is an archaic form of English currency (20 marks was quite a generous amount).
Mrs Burdett was to be paid in marks, which is an archaic form of English currency (20 marks was quite a generous amount).
In 1189 King William had taken advantage of Richard's financial needs to buy his freedom from English allegiance for 10,000 marks.
2.1A denomination of weight for gold and silver, formerly used throughout western Europe and typically equal to 8 ounces (226.8 grams).
Inside there were about two hundred gold marks.
More example sentences - If that lord fails to do this, that lord must pay me 46 marks of silver.
If that lord fails to do this, that lord must pay me 46 marks of silver.
He produces a silver mark from his purse and holds it up for the man to see.
My prices vary, but most are around fifty gold marks.
Russia was also obliged to pay 6 billion gold marks in reparations.
3 - (also marka)
(also marka) - The basic monetary unit of Bosnia and Herzegovina, equal to 100 fening.
The basic monetary unit of Bosnia and Herzegovina, equal to 100 fening.
When the new government took over, they issued a new currency, the Bosnian Convertible Marka, and tied it to the German Mark.
More example sentences - It is not fair that such cuts apply equally to veterans with compensation for their wartime service of only 250 Bosnian marka ($177/month).
It is not fair that such cuts apply equally to veterans with compensation for their wartime service of only 250 Bosnian marka ($177/month).
Origin - Old English marc, from Old Norse mrk; probably related to mark.
Old English marc, from Old Norse mrk; probably related to mark.
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Rail - Cross members of panel doors or of a sash. Also, a wall or open balustrade placed at the edge of a staircase, walkway bridge, or elevated surface to prevent people from falling off. Any relatively lightweight horizontal element, especially those found in fences (split rail).
Cross members of panel doors or of a sash. Also, a wall or open balustrade placed at the edge of a staircase, walkway bridge, or elevated surface to prevent people from falling off. Any relatively lightweight horizontal element, especially those found in fences (split rail).
Railroad tie - - Black, tar and preservative impregnated, 6" X 8" and 6'-8' long wooden timber that was used to hold railroad track in place. Normally used as a member of a retaining wall.
- Black, tar and preservative impregnated, 6" X 8" and 6'-8' long wooden timber that was used to hold railroad track in place. Normally used as a member of a retaining wall.
Number - A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, 4, and so forth.[1] Numbers can be represented in language with number words. More universally, individual numbers can be represented by symbols, called numerals; for example, "5" is a numeral that represents the number five. As only a relatively small number of symbols can be memorized, basic numerals are commonly organized in a numeral system, which is an organized way to represent any number. The most common numeral system is the HinduArabic numeral system, which allows for the representation of any number using a combination of ten fundamental numeric symbols, called digits.[2][3] In addition to their use in counting and measuring, numerals are often used for labels (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, a numeral is not clearly distinguished from the number that it represents.
A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, 4, and so forth.[1] Numbers can be represented in language with number words. More universally, individual numbers can be represented by symbols, called numerals; for example, "5" is a numeral that represents the number five. As only a relatively small number of symbols can be memorized, basic numerals are commonly organized in a numeral system, which is an organized way to represent any number. The most common numeral system is the HinduArabic numeral system, which allows for the representation of any number using a combination of ten fundamental numeric symbols, called digits.[2][3] In addition to their use in counting and measuring, numerals are often used for labels (as with telephone numbers), for ordering (as with serial numbers), and for codes (as with ISBNs). In common usage, a numeral is not clearly distinguished from the number that it represents.
Besides their practical uses, numbers have cultural significance throughout the world.[8][9] For example, in Western society, the number 13 is often regarded as unlucky, and "a million" may signify "a lot" rather than an exact quantity.[8] Though it is now regarded as pseudoscience, belief in a mystical significance of numbers, known as numerology, permeated ancient and medieval thought.[10] Numerology heavily influenced the development of Greek mathematics, stimulating the investigation of many problems in number theory which are still of interest today.[10]
During the 19th century, mathematicians began to develop many different abstractions which share certain properties of numbers, and may be seen as extending the concept. Among the first were the hypercomplex numbers, which consist of various extensions or modifications of the complex number system. In modern mathematics, number systems (sets) are considered important special examples of more general categories such as rings and fields, and the application of the term "number" is a matter of convention, without fundamental significance.[11]
Numerals - Numbers should be distinguished from numerals, the symbols used to represent numbers. The Egyptians invented the first ciphered numeral system, and the Greeks followed by mapping their counting numbers onto Ionian and Doric alphabets.[12] Roman numerals, a system that used combinations of letters from the Roman alphabet, remained dominant in Europe until the spread of the superior HinduArabic numeral system around the late 14th century, and the HinduArabic numeral system remains the most common system for representing numbers in the world today.[13] The key to the effectiveness of the system was the symbol for zero, which was developed by ancient Indian mathematicians around 500 AD.[13]
Numbers should be distinguished from numerals, the symbols used to represent numbers. The Egyptians invented the first ciphered numeral system, and the Greeks followed by mapping their counting numbers onto Ionian and Doric alphabets.[12] Roman numerals, a system that used combinations of letters from the Roman alphabet, remained dominant in Europe until the spread of the superior HinduArabic numeral system around the late 14th century, and the HinduArabic numeral system remains the most common system for representing numbers in the world today.[13] The key to the effectiveness of the system was the symbol for zero, which was developed by ancient Indian mathematicians around 500 AD.[13]
First use of numbers - Bones and other artifacts have been discovered with marks cut into them that many believe are tally marks.[14] These tally marks may have been used for counting elapsed time, such as numbers of days, lunar cycles or keeping records of quantities, such as of animals.
Bones and other artifacts have been discovered with marks cut into them that many believe are tally marks.[14] These tally marks may have been used for counting elapsed time, such as numbers of days, lunar cycles or keeping records of quantities, such as of animals.
A tallying system has no concept of place value (as in modern decimal notation), which limits its representation of large numbers. Nonetheless tallying systems are considered the first kind of abstract numeral system.
The first known system with place value was the Mesopotamian base 60 system (c. 3400 BC) and the earliest known base 10 system dates to 3100 BC in Egypt.[15]
Zero - The first known documented use of zero dates to AD 628, and appeared in the Brhmasphuasiddhnta, the main work of the Indian mathematician Brahmagupta. He treated 0 as a number and discussed operations involving it, including division. By this time (the 7th century) the concept had clearly reached Cambodia as Khmer numerals, and documentation shows the idea later spreading to China and the Islamic world.
The first known documented use of zero dates to AD 628, and appeared in the Brhmasphuasiddhnta, the main work of the Indian mathematician Brahmagupta. He treated 0 as a number and discussed operations involving it, including division. By this time (the 7th century) the concept had clearly reached Cambodia as Khmer numerals, and documentation shows the idea later spreading to China and the Islamic world.
The number 605 in Khmer numerals, from an inscription from 683 AD. Early use of zero as a decimal figure.
Brahmagupta's Brhmasphuasiddhnta is the first book that mentions zero as a number, hence Brahmagupta is usually considered the first to formulate the concept of zero. He gave rules of using zero with negative and positive numbers, such as "zero plus a positive number is a positive number, and a negative number plus zero is the negative number." The Brhmasphuasiddhnta is the earliest known text to treat zero as a number in its own right, rather than as simply a placeholder digit in representing another number as was done by the Babylonians or as a symbol for a lack of quantity as was done by Ptolemy and the Romans.
The use of 0 as a number should be distinguished from its use as a placeholder numeral in place-value systems. Many ancient texts used 0. Babylonian and Egyptian texts used it. Egyptians used the word nfr to denote zero balance in double entry accounting. Indian texts used a Sanskrit word Shunye or shunya to refer to the concept of void. In mathematics texts this word often refers to the number zero.[16] In a similar vein, Pini (5th century BC) used the null (zero) operator in the Ashtadhyayi, an early example of an algebraic grammar for the Sanskrit language (also see Pingala).
There are other uses of zero before Brahmagupta, though the documentation is not as complete as it is in the Brhmasphuasiddhnta.
Records show that the Ancient Greeks seemed unsure about the status of 0 as a number: they asked themselves "how can 'nothing' be something?" leading to interesting philosophical and, by the Medieval period, religious arguments about the nature and existence of 0 and the vacuum. The paradoxes of Zeno of Elea depend in part on the uncertain interpretation of 0. (The ancient Greeks even questioned whether 1 was a number.)
The late Olmec people of south-central Mexico began to use a symbol for zero, a shell glyph, in the New World, possibly by the 4th century BC but certainly by 40 BC, which became an integral part of Maya numerals and the Maya calendar. Maya arithmetic used base 4 and base 5 written as base 20. George I. Snchez in 1961 reported a base 4, base 5 "finger" abacus.[17][better source needed]
By 130 AD, Ptolemy, influenced by Hipparchus and the Babylonians, was using a symbol for 0 (a small circle with a long overbar) within a sexagesimal numeral system otherwise using alphabetic Greek numerals. Because it was used alone, not as just a placeholder, this Hellenistic zero was the first documented use of a true zero in the Old World. In later Byzantine manuscripts of his Syntaxis Mathematica (Almagest), the Hellenistic zero had morphed into the Greek letter Omicron (otherwise meaning 70).
Another true zero was used in tables alongside Roman numerals by 525 (first known use by Dionysius Exiguus), but as a word, nulla meaning nothing, not as a symbol. When division produced 0 as a remainder, nihil, also meaning nothing, was used. These medieval zeros were used by all future medieval computists (calculators of Easter). An isolated use of their initial, N, was used in a table of Roman numerals by Bede or a colleague about 725, a true zero symbol.
Negative numbers - The abstract concept of negative numbers was recognized as early as 10050 BC in China. The Nine Chapters on the Mathematical Art contains methods for finding the areas of figures; red rods were used to denote positive coefficients, black for negative.[18] The first reference in a Western work was in the 3rd century AD in Greece. Diophantus referred to the equation equivalent to 4x + 20 = 0 (the solution is negative) in Arithmetica, saying that the equation gave an absurd result.
The abstract concept of negative numbers was recognized as early as 10050 BC in China. The Nine Chapters on the Mathematical Art contains methods for finding the areas of figures; red rods were used to denote positive coefficients, black for negative.[18] The first reference in a Western work was in the 3rd century AD in Greece. Diophantus referred to the equation equivalent to 4x + 20 = 0 (the solution is negative) in Arithmetica, saying that the equation gave an absurd result.
During the 600s, negative numbers were in use in India to represent debts. Diophantus' previous reference was discussed more explicitly by Indian mathematician Brahmagupta, in Brhmasphuasiddhnta in 628, who used negative numbers to produce the general form quadratic formula that remains in use today. However, in the 12th century in India, Bhaskara gives negative roots for quadratic equations but says the negative value "is in this case not to be taken, for it is inadequate; people do not approve of negative roots".
European mathematicians, for the most part, resisted the concept of negative numbers until the 17th century, although Fibonacci allowed negative solutions in financial problems where they could be interpreted as debts (chapter 13 of Liber Abaci, 1202) and later as losses (in Flos). At the same time, the Chinese were indicating negative numbers by drawing a diagonal stroke through the right-most non-zero digit of the corresponding positive number's numeral.[19] The first use of negative numbers in a European work was by Nicolas Chuquet during the 15th century. He used them as exponents, but referred to them as "absurd numbers".
As recently as the 18th century, it was common practice to ignore any negative results returned by equations on the assumption that they were meaningless, just as Ren Descartes did with negative solutions in a Cartesian coordinate system.
Rational numbers - It is likely that the concept of fractional numbers dates to prehistoric times. The Ancient Egyptians used their Egyptian fraction notation for rational numbers in mathematical texts such as the Rhind Mathematical Papyrus and the Kahun Papyrus. Classical Greek and Indian mathematicians made studies of the theory of rational numbers, as part of the general study of number theory.[citation needed] The best known of these is Euclid's Elements, dating to roughly 300 BC. Of the Indian texts, the most relevant is the Sthananga Sutra, which also covers number theory as part of a general study of mathematics.
It is likely that the concept of fractional numbers dates to prehistoric times. The Ancient Egyptians used their Egyptian fraction notation for rational numbers in mathematical texts such as the Rhind Mathematical Papyrus and the Kahun Papyrus. Classical Greek and Indian mathematicians made studies of the theory of rational numbers, as part of the general study of number theory.[citation needed] The best known of these is Euclid's Elements, dating to roughly 300 BC. Of the Indian texts, the most relevant is the Sthananga Sutra, which also covers number theory as part of a general study of mathematics.
The concept of decimal fractions is closely linked with decimal place-value notation; the two seem to have developed in tandem. For example, it is common for the Jain math sutra to include calculations of decimal-fraction approximations to pi or the square root of 2.[citation needed] Similarly, Babylonian math texts used sexagesimal (base 60) fractions with great frequency.
Irrational numbers - The earliest known use of irrational numbers was in the Indian Sulba Sutras composed between 800 and 500 BC.[20][better source needed] The first existence proofs of irrational numbers is usually attributed to Pythagoras, more specifically to the Pythagorean Hippasus of Metapontum, who produced a (most likely geometrical) proof of the irrationality of the square root of 2. The story goes that Hippasus discovered irrational numbers when trying to represent the square root of 2 as a fraction. However, Pythagoras believed in the absoluteness of numbers, and could not accept the existence of irrational numbers. He could not disprove their existence through logic, but he could not accept irrational numbers, and so, allegedly and frequently reported, he sentenced Hippasus to death by drowning, to impede spreading of this disconcerting news.[21][better source needed]
The earliest known use of irrational numbers was in the Indian Sulba Sutras composed between 800 and 500 BC.[20][better source needed] The first existence proofs of irrational numbers is usually attributed to Pythagoras, more specifically to the Pythagorean Hippasus of Metapontum, who produced a (most likely geometrical) proof of the irrationality of the square root of 2. The story goes that Hippasus discovered irrational numbers when trying to represent the square root of 2 as a fraction. However, Pythagoras believed in the absoluteness of numbers, and could not accept the existence of irrational numbers. He could not disprove their existence through logic, but he could not accept irrational numbers, and so, allegedly and frequently reported, he sentenced Hippasus to death by drowning, to impede spreading of this disconcerting news.[21][better source needed]
The 16th century brought final European acceptance of negative integral and fractional numbers. By the 17th century, mathematicians generally used decimal fractions with modern notation. It was not, however, until the 19th century that mathematicians separated irrationals into algebraic and transcendental parts, and once more undertook the scientific study of irrationals. It had remained almost dormant since Euclid. In 1872, the publication of the theories of Karl Weierstrass (by his pupil E. Kossak), Eduard Heine,[22] Georg Cantor,[23] and Richard Dedekind[24] was brought about. In 1869, Charles Mray had taken the same point of departure as Heine, but the theory is generally referred to the year 1872. Weierstrass's method was completely set forth by Salvatore Pincherle (1880), and Dedekind's has received additional prominence through the author's later work (1888) and endorsement by Paul Tannery (1894). Weierstrass, Cantor, and Heine base their theories on infinite series, while Dedekind founds his on the idea of a cut (Schnitt) in the system of real numbers, separating all rational numbers into two groups having certain characteristic properties. The subject has received later contributions at the hands of Weierstrass, Kronecker,[25] and Mray.
The search for roots of quintic and higher degree equations was an important development, the AbelRuffini theorem (Ruffini 1799, Abel 1824) showed that they could not be solved by radicals (formulas involving only arithmetical operations and roots). Hence it was necessary to consider the wider set of algebraic numbers (all solutions to polynomial equations). Galois (1832) linked polynomial equations to group theory giving rise to the field of Galois theory.
Continued fractions, closely related to irrational numbers (and due to Cataldi, 1613), received attention at the hands of Euler,[26] and at the opening of the 19th century were brought into prominence through the writings of Joseph Louis Lagrange. Other noteworthy contributions have been made by Druckenmller (1837), Kunze (1857), Lemke (1870), and Gnther (1872). Ramus[27] first connected the subject with determinants, resulting, with the subsequent contributions of Heine,[28] Mbius, and Gnther,[29] in the theory of Kettenbruchdeterminanten.
Infinity and infinitesimals - The earliest known conception of mathematical infinity appears in the Yajur Veda, an ancient Indian script, which at one point states, "If you remove a part from infinity or add a part to infinity, still what remains is infinity." Infinity was a popular topic of philosophical study among the Jain mathematicians c. 400 BC. They distinguished between five types of infinity: infinite in one and two directions, infinite in area, infinite everywhere, and infinite perpetually. The symbol {\displaystyle {\text{}}} is often used to represent an infinite quantity.
The earliest known conception of mathematical infinity appears in the Yajur Veda, an ancient Indian script, which at one point states, "If you remove a part from infinity or add a part to infinity, still what remains is infinity." Infinity was a popular topic of philosophical study among the Jain mathematicians c. 400 BC. They distinguished between five types of infinity: infinite in one and two directions, infinite in area, infinite everywhere, and infinite perpetually. The symbol {\displaystyle {\text{}}} is often used to represent an infinite quantity.
In the 1960s, Abraham Robinson showed how infinitely large and infinitesimal numbers can be rigorously defined and used to develop the field of nonstandard analysis. The system of hyperreal numbers represents a rigorous method of treating the ideas about infinite and infinitesimal numbers that had been used casually by mathematicians, scientists, and engineers ever since the invention of infinitesimal calculus by Newton and Leibniz.
A modern geometrical version of infinity is given by projective geometry, which introduces "ideal points at infinity", one for each spatial direction. Each family of parallel lines in a given direction is postulated to converge to the corresponding ideal point. This is closely related to the idea of vanishing points in perspective drawing.
Complex numbers - The earliest fleeting reference to square roots of negative numbers occurred in the work of the mathematician and inventor Heron of Alexandria in the 1st century AD, when he considered the volume of an impossible frustum of a pyramid. They became more prominent when in the 16th century closed formulas for the roots of third and fourth degree polynomials were discovered by Italian mathematicians such as Niccol Fontana Tartaglia and Gerolamo Cardano. It was soon realized that these formulas, even if one was only interested in real solutions, sometimes required the manipulation of square roots of negative numbers.
The earliest fleeting reference to square roots of negative numbers occurred in the work of the mathematician and inventor Heron of Alexandria in the 1st century AD, when he considered the volume of an impossible frustum of a pyramid. They became more prominent when in the 16th century closed formulas for the roots of third and fourth degree polynomials were discovered by Italian mathematicians such as Niccol Fontana Tartaglia and Gerolamo Cardano. It was soon realized that these formulas, even if one was only interested in real solutions, sometimes required the manipulation of square roots of negative numbers.
This was doubly unsettling since they did not even consider negative numbers to be on firm ground at the time. When Ren Descartes coined the term "imaginary" for these quantities in 1637, he intended it as derogatory. (See imaginary number for a discussion of the "reality" of complex numbers.) A further source of confusion was that the equation
seemed capriciously inconsistent with the algebraic identity - a b = a b , {\displaystyle {\sqrt {a}}{\sqrt {b}}={\sqrt {ab}},}
a b = a b , {\displaystyle {\sqrt {a}}{\sqrt {b}}={\sqrt {ab}},}
which is valid for positive real numbers a and b, and was also used in complex number calculations with one of a, b positive and the other negative. The incorrect use of this identity, and the related identity
1 a = 1 a {\displaystyle {\frac {1}{\sqrt {a}}}={\sqrt {\frac {1}{a}}}}
in the case when both a and b are negative even bedeviled Euler. This difficulty eventually led him to the convention of using the special symbol i in place of 1 {\displaystyle {\sqrt {-1}}} to guard against this mistake.
cos + i sin = e i . {\displaystyle \cos \theta +i\sin \theta =e^{i\theta }.}
The existence of complex numbers was not completely accepted until Caspar Wessel described the geometrical interpretation in 1799. Carl Friedrich Gauss rediscovered and popularized it several years later, and as a result the theory of complex numbers received a notable expansion. The idea of the graphic representation of complex numbers had appeared, however, as early as 1685, in Wallis's De algebra tractatus.
Also in 1799, Gauss provided the first generally accepted proof of the fundamental theorem of algebra, showing that every polynomial over the complex numbers has a full set of solutions in that realm. The general acceptance of the theory of complex numbers is due to the labors of Augustin Louis Cauchy and Niels Henrik Abel, and especially the latter, who was the first to boldly use complex numbers with a success that is well known.[peacock term]
Gauss studied complex numbers of the form a + bi, where a and b are integral, or rational (and i is one of the two roots of x2 + 1 = 0). His student, Gotthold Eisenstein, studied the type a + b, where is a complex root of x3 1 = 0. Other such classes (called cyclotomic fields) of complex numbers derive from the roots of unity xk 1 = 0 for higher values of k. This generalization is largely due to Ernst Kummer, who also invented ideal numbers, which were expressed as geometrical entities by Felix Klein in 1893.
In 1796, Adrien-Marie Legendre conjectured the prime number theorem, describing the asymptotic distribution of primes. Other results concerning the distribution of the primes include Euler's proof that the sum of the reciprocals of the primes diverges, and the Goldbach conjecture, which claims that any sufficiently large even number is the sum of two primes. Yet another conjecture related to the distribution of prime numbers is the Riemann hypothesis, formulated by Bernhard Riemann in 1859. The prime number theorem was finally proved by Jacques Hadamard and Charles de la Valle-Poussin in 1896. Goldbach and Riemann's conjectures remain unproven and unrefuted.
Main classification - "Number system" redirects here. For systems for expressing numbers, see Numeral system.
"Number system" redirects here. For systems for expressing numbers, see Numeral system.
Numbers can be classified into sets, called number systems, such as the natural numbers and the real numbers.[31] The major categories of numbers are as follows:
N 0 {\displaystyle \mathbb {N} _{0}} or N 1 {\displaystyle \mathbb {N} _{1}} are sometimes used.
a + bi where a and b are real numbers and i is a formal square root of 1
There is generally no problem in identifying each number system with a proper subset of the next one (by abuse of notation), because each of these number systems is canonically isomorphic to a proper subset of the next one.[citation needed] The resulting hierarchy allows, for example, to talk, formally correctly, about real numbers that are rational numbers, and is expressed symbolically by writing
Natural numbers - The most familiar numbers are the natural numbers (sometimes called whole numbers or counting numbers): 1, 2, 3, and so on. Traditionally, the sequence of natural numbers started with 1 (0 was not even considered a number for the Ancient Greeks.) However, in the 19th century, set theorists and other mathematicians started including 0 (cardinality of the empty set, i.e. 0 elements, where 0 is thus the smallest cardinal number) in the set of natural numbers.[32][33] Today, different mathematicians use the term to describe both sets, including 0 or not. The mathematical symbol for the set of all natural numbers is N, also written N {\displaystyle \mathbb {N} } , and sometimes N 0 {\displaystyle \mathbb {N} _{0}} or N 1 {\displaystyle \mathbb {N} _{1}} when it is necessary to indicate whether the set should start with 0 or 1, respectively.
The most familiar numbers are the natural numbers (sometimes called whole numbers or counting numbers): 1, 2, 3, and so on. Traditionally, the sequence of natural numbers started with 1 (0 was not even considered a number for the Ancient Greeks.) However, in the 19th century, set theorists and other mathematicians started including 0 (cardinality of the empty set, i.e. 0 elements, where 0 is thus the smallest cardinal number) in the set of natural numbers.[32][33] Today, different mathematicians use the term to describe both sets, including 0 or not. The mathematical symbol for the set of all natural numbers is N, also written N {\displaystyle \mathbb {N} } , and sometimes N 0 {\displaystyle \mathbb {N} _{0}} or N 1 {\displaystyle \mathbb {N} _{1}} when it is necessary to indicate whether the set should start with 0 or 1, respectively.
In the base 10 numeral system, in almost universal use today for mathematical operations, the symbols for natural numbers are written using ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. The radix or base is the number of unique numerical digits, including zero, that a numeral system uses to represent numbers (for the decimal system, the radix is 10). In this base 10 system, the rightmost digit of a natural number has a place value of 1, and every other digit has a place value ten times that of the place value of the digit to its right.
In set theory, which is capable of acting as an axiomatic foundation for modern mathematics,[34] natural numbers can be represented by classes of equivalent sets. For instance, the number 3 can be represented as the class of all sets that have exactly three elements. Alternatively, in Peano Arithmetic, the number 3 is represented as sss0, where s is the "successor" function (i.e., 3 is the third successor of 0). Many different representations are possible; all that is needed to formally represent 3 is to inscribe a certain symbol or pattern of symbols three times.
Integers - The negative of a positive integer is defined as a number that produces 0 when it is added to the corresponding positive integer. Negative numbers are usually written with a negative sign (a minus sign). As an example, the negative of 7 is written 7, and 7 + (7) = 0. When the set of negative numbers is combined with the set of natural numbers (including 0), the result is defined as the set of integers, Z also written Z {\displaystyle \mathbb {Z} } . Here the letter Z comes from German Zahl 'number'. The set of integers forms a ring with the operations addition and multiplication.[35]
The negative of a positive integer is defined as a number that produces 0 when it is added to the corresponding positive integer. Negative numbers are usually written with a negative sign (a minus sign). As an example, the negative of 7 is written 7, and 7 + (7) = 0. When the set of negative numbers is combined with the set of natural numbers (including 0), the result is defined as the set of integers, Z also written Z {\displaystyle \mathbb {Z} } . Here the letter Z comes from German Zahl 'number'. The set of integers forms a ring with the operations addition and multiplication.[35]
The natural numbers form a subset of the integers. As there is no common standard for the inclusion or not of zero in the natural numbers, the natural numbers without zero are commonly referred to as positive integers, and the natural numbers with zero are referred to as non-negative integers.
Rational numbers - A rational number is a number that can be expressed as a fraction with an integer numerator and a positive integer denominator. Negative denominators are allowed, but are commonly avoided, as every rational number is equal to a fraction with positive denominator. Fractions are written as two integers, the numerator and the denominator, with a dividing bar between them. The fraction m/n represents m parts of a whole divided into n equal parts. Two different fractions may correspond to the same rational number; for example 1/2 and 2/4 are equal, that is:
A rational number is a number that can be expressed as a fraction with an integer numerator and a positive integer denominator. Negative denominators are allowed, but are commonly avoided, as every rational number is equal to a fraction with positive denominator. Fractions are written as two integers, the numerator and the denominator, with a dividing bar between them. The fraction m/n represents m parts of a whole divided into n equal parts. Two different fractions may correspond to the same rational number; for example 1/2 and 2/4 are equal, that is:
a b = c d {\displaystyle {a \over b}={c \over d}} if and only if a d = c b . {\displaystyle {a\times d}={c\times b}.}
If the absolute value of m is greater than n (supposed to be positive), then the absolute value of the fraction is greater than 1. Fractions can be greater than, less than, or equal to 1 and can also be positive, negative, or 0. The set of all rational numbers includes the integers since every integer can be written as a fraction with denominator 1. For example 7 can be written 7/1. The symbol for the rational numbers is Q (for quotient), also written Q {\displaystyle \mathbb {Q} } .
Real numbers - The symbol for the real numbers is R, also written as R . {\displaystyle \mathbb {R} .} They include all the measuring numbers. Every real number corresponds to a point on the number line. The following paragraph will focus primarily on positive real numbers. The treatment of negative real numbers is according to the general rules of arithmetic and their denotation is simply prefixing the corresponding positive numeral by a minus sign, e.g. 123.456.
The symbol for the real numbers is R, also written as R . {\displaystyle \mathbb {R} .} They include all the measuring numbers. Every real number corresponds to a point on the number line. The following paragraph will focus primarily on positive real numbers. The treatment of negative real numbers is according to the general rules of arithmetic and their denotation is simply prefixing the corresponding positive numeral by a minus sign, e.g. 123.456.
Most real numbers can only be approximated by decimal numerals, in which a decimal point is placed to the right of the digit with place value 1. Each digit to the right of the decimal point has a place value one-tenth of the place value of the digit to its left. For example, 123.456 represents 123456/1000, or, in words, one hundred, two tens, three ones, four tenths, five hundredths, and six thousandths. A real number can be expressed by a finite number of decimal digits only if it is rational and its fractional part has a denominator whose prime factors are 2 or 5 or both, because these are the prime factors of 10, the base of the decimal system. Thus, for example, one half is 0.5, one fifth is 0.2, one-tenth is 0.1, and one fiftieth is 0.02. Representing other real numbers as decimals would require an infinite sequence of digits to the right of the decimal point. If this infinite sequence of digits follows a pattern, it can be written with an ellipsis or another notation that indicates the repeating pattern. Such a decimal is called a repeating decimal. Thus 1/3 can be written as 0.333..., with an ellipsis to indicate that the pattern continues. Forever repeating 3s are also written as 0.3.[36]
It turns out that these repeating decimals (including the repetition of zeroes) denote exactly the rational numbers, i.e., all rational numbers are also real numbers, but it is not the case that every real number is rational. A real number that is not rational is called irrational. A famous irrational real number is the number , the ratio of the circumference of any circle to its diameter. When pi is written as
as it sometimes is, the ellipsis does not mean that the decimals repeat (they do not), but rather that there is no end to them. It has been proved that is irrational. Another well-known number, proven to be an irrational real number, is
the square root of 2, that is, the unique positive real number whose square is 2. Both these numbers have been approximated (by computer) to trillions ( 1 trillion = 1012 = 1,000,000,000,000 ) of digits.
Not only these prominent examples but almost all real numbers are irrational and therefore have no repeating patterns and hence no corresponding decimal numeral. They can only be approximated by decimal numerals, denoting rounded or truncated real numbers. Any rounded or truncated number is necessarily a rational number, of which there are only countably many. All measurements are, by their nature, approximations, and always have a margin of error. Thus 123.456 is considered an approximation of any real number greater or equal to 1234555/10000 and strictly less than 1234565/10000 (rounding to 3 decimals), or of any real number greater or equal to 123456/1000 and strictly less than 123457/1000 (truncation after the 3. decimal). Digits that suggest a greater accuracy than the measurement itself does, should be removed. The remaining digits are then called significant digits. For example, measurements with a ruler can seldom be made without a margin of error of at least 0.001 m. If the sides of a rectangle are measured as 1.23 m and 4.56 m, then multiplication gives an area for the rectangle between 5.614591 m2 and 5.603011 m2. Since not even the second digit after the decimal place is preserved, the following digits are not significant. Therefore, the result is usually rounded to 5.61.
Just as the same fraction can be written in more than one way, the same real number may have more than one decimal representation. For example, 0.999..., 1.0, 1.00, 1.000, ..., all represent the natural number 1. A given real number has only the following decimal representations: an approximation to some finite number of decimal places, an approximation in which a pattern is established that continues for an unlimited number of decimal places or an exact value with only finitely many decimal places. In this last case, the last non-zero digit may be replaced by the digit one smaller followed by an unlimited number of 9's, or the last non-zero digit may be followed by an unlimited number of zeros. Thus the exact real number 3.74 can also be written 3.7399999999... and 3.74000000000.... Similarly, a decimal numeral with an unlimited number of 0's can be rewritten by dropping the 0's to the right of the decimal place, and a decimal numeral with an unlimited number of 9's can be rewritten by increasing the rightmost -9 digit by one, changing all the 9's to the right of that digit to 0's. Finally, an unlimited sequence of 0's to the right of the decimal place can be dropped. For example, 6.849999999999... = 6.85 and 6.850000000000... = 6.85. Finally, if all of the digits in a numeral are 0, the number is 0, and if all of the digits in a numeral are an unending string of 9's, you can drop the nines to the right of the decimal place, and add one to the string of 9s to the left of the decimal place. For example, 99.999... = 100.
The real numbers also have an important but highly technical property called the least upper bound property.
It can be shown that any ordered field, which is also complete, is isomorphic to the real numbers. The real numbers are not, however, an algebraically closed field, because they do not include a solution (often called a square root of minus one) to the algebraic equation x 2 + 1 = 0 {\displaystyle x^{2}+1=0} .
Complex numbers - Moving to a greater level of abstraction, the real numbers can be extended to the complex numbers. This set of numbers arose historically from trying to find closed formulas for the roots of cubic and quadratic polynomials. This led to expressions involving the square roots of negative numbers, and eventually to the definition of a new number: a square root of 1, denoted by i, a symbol assigned by Leonhard Euler, and called the imaginary unit. The complex numbers consist of all numbers of the form
Moving to a greater level of abstraction, the real numbers can be extended to the complex numbers. This set of numbers arose historically from trying to find closed formulas for the roots of cubic and quadratic polynomials. This led to expressions involving the square roots of negative numbers, and eventually to the definition of a new number: a square root of 1, denoted by i, a symbol assigned by Leonhard Euler, and called the imaginary unit. The complex numbers consist of all numbers of the form
a + b i {\displaystyle \,a+bi}
where a and b are real numbers. Because of this, complex numbers correspond to points on the complex plane, a vector space of two real dimensions. In the expression a + bi, the real number a is called the real part and b is called the imaginary part. If the real part of a complex number is 0, then the number is called an imaginary number or is referred to as purely imaginary; if the imaginary part is 0, then the number is a real number. Thus the real numbers are a subset of the complex numbers. If the real and imaginary parts of a complex number are both integers, then the number is called a Gaussian integer. The symbol for the complex numbers is C or C {\displaystyle \mathbb {C} } .
The fundamental theorem of algebra asserts that the complex numbers form an algebraically closed field, meaning that every polynomial with complex coefficients has a root in the complex numbers. Like the reals, the complex numbers form a field, which is complete, but unlike the real numbers, it is not ordered. That is, there is no consistent meaning assignable to saying that I is greater than 1, nor is there any meaning in saying that I is less than 1. In technical terms, the complex numbers lack a total order that is compatible with field operations.
Subclasses of the integers - Even and odd numbers
Even and odd numbers - An even number is an integer that is "evenly divisible" by two, that is divisible by two without remainder; an odd number is an integer that is not even. (The old-fashioned term "evenly divisible" is now almost always shortened to "divisible".) Any odd number n may be constructed by the formula n = 2k + 1, for a suitable integer k. Starting with k = 0, the first non-negative odd numbers are {1, 3, 5, 7, ...}. Any even number m has the form m = 2k where k is again an integer. Similarly, the first non-negative even numbers are {0, 2, 4, 6, ...}.
An even number is an integer that is "evenly divisible" by two, that is divisible by two without remainder; an odd number is an integer that is not even. (The old-fashioned term "evenly divisible" is now almost always shortened to "divisible".) Any odd number n may be constructed by the formula n = 2k + 1, for a suitable integer k. Starting with k = 0, the first non-negative odd numbers are {1, 3, 5, 7, ...}. Any even number m has the form m = 2k where k is again an integer. Similarly, the first non-negative even numbers are {0, 2, 4, 6, ...}.
Prime numbers - A prime number, often shortened to just prime, is an integer greater than 1 that is not the product of two smaller positive integers. The first few prime numbers are 2, 3, 5, 7, and 11. There is no such simple formula as for odd and even numbers to generate the prime numbers. The primes have been widely studied for more than 2000 years and have led to many questions, only some of which have been answered. The study of these questions belongs to number theory. Goldbach's conjecture is an example of a still unanswered question: "Is every even number the sum of two primes?"
A prime number, often shortened to just prime, is an integer greater than 1 that is not the product of two smaller positive integers. The first few prime numbers are 2, 3, 5, 7, and 11. There is no such simple formula as for odd and even numbers to generate the prime numbers. The primes have been widely studied for more than 2000 years and have led to many questions, only some of which have been answered. The study of these questions belongs to number theory. Goldbach's conjecture is an example of a still unanswered question: "Is every even number the sum of two primes?"
One answered question, as to whether every integer greater than one is a product of primes in only one way, except for a rearrangement of the primes, was confirmed; this proven claim is called the fundamental theorem of arithmetic. A proof appears in Euclid's Elements.
Other classes of integers - Many subsets of the natural numbers have been the subject of specific studies and have been named, often after the first mathematician that has studied them. Example of such sets of integers are Fibonacci numbers and perfect numbers. For more examples, see Integer sequence.
Many subsets of the natural numbers have been the subject of specific studies and have been named, often after the first mathematician that has studied them. Example of such sets of integers are Fibonacci numbers and perfect numbers. For more examples, see Integer sequence.
Subclasses of the complex numbers - Algebraic, irrational and transcendental numbers
Algebraic, irrational and transcendental numbers - Algebraic numbers are those that are a solution to a polynomial equation with integer coefficients. Real numbers that are not rational numbers are called irrational numbers. Complex numbers which are not algebraic are called transcendental numbers. The algebraic numbers that are solutions of a monic polynomial equation with integer coefficients are called algebraic integers.
Algebraic numbers are those that are a solution to a polynomial equation with integer coefficients. Real numbers that are not rational numbers are called irrational numbers. Complex numbers which are not algebraic are called transcendental numbers. The algebraic numbers that are solutions of a monic polynomial equation with integer coefficients are called algebraic integers.
Constructible numbers - Motivated by the classical problems of constructions with straightedge and compass, the constructible numbers are those complex numbers whose real and imaginary parts can be constructed using straightedge and compass, starting from a given segment of unit length, in a finite number of steps.
Motivated by the classical problems of constructions with straightedge and compass, the constructible numbers are those complex numbers whose real and imaginary parts can be constructed using straightedge and compass, starting from a given segment of unit length, in a finite number of steps.
Computable numbers - A computable number, also known as recursive number, is a real number such that there exists an algorithm which, given a positive number n as input, produces the first n digits of the computable number's decimal representation. Equivalent definitions can be given using -recursive functions, Turing machines or -calculus. The computable numbers are stable for all usual arithmetic operations, including the computation of the roots of a polynomial, and thus form a real closed field that contains the real algebraic numbers.
A computable number, also known as recursive number, is a real number such that there exists an algorithm which, given a positive number n as input, produces the first n digits of the computable number's decimal representation. Equivalent definitions can be given using -recursive functions, Turing machines or -calculus. The computable numbers are stable for all usual arithmetic operations, including the computation of the roots of a polynomial, and thus form a real closed field that contains the real algebraic numbers.
The computable numbers may be viewed as the real numbers that may be exactly represented in a computer: a computable number is exactly represented by its first digits and a program for computing further digits. However, the computable numbers are rarely used in practice. One reason is that there is no algorithm for testing the equality of two computable numbers. More precisely, there cannot exist any algorithm which takes any computable number as an input, and decides in every case if this number is equal to zero or not.
The set of computable numbers has the same cardinality as the natural numbers. Therefore, almost all real numbers are non-computable. However, it is very difficult to produce explicitly a real number that is not computable.
Extensions of the concept - p-adic numbers
p-adic numbers - The p-adic numbers may have infinitely long expansions to the left of the decimal point, in the same way that real numbers may have infinitely long expansions to the right. The number system that results depends on what base is used for the digits: any base is possible, but a prime number base provides the best mathematical properties. The set of the p-adic numbers contains the rational numbers, but is not contained in the complex numbers.
The p-adic numbers may have infinitely long expansions to the left of the decimal point, in the same way that real numbers may have infinitely long expansions to the right. The number system that results depends on what base is used for the digits: any base is possible, but a prime number base provides the best mathematical properties. The set of the p-adic numbers contains the rational numbers, but is not contained in the complex numbers.
The elements of an algebraic function field over a finite field and algebraic numbers have many similar properties (see Function field analogy). Therefore, they are often regarded as numbers by number theorists. The p-adic numbers play an important role in this analogy.
Hypercomplex numbers - Some number systems that are not included in the complex numbers may be constructed from the real numbers in a way that generalize the construction of the complex numbers. They are sometimes called hypercomplex numbers. They include the quaternions H, introduced by Sir William Rowan Hamilton, in which multiplication is not commutative, the octonions, in which multiplication is not associative in addition to not being commutative, and the sedenions, in which multiplication is not alternative, neither associative nor commutative.
Some number systems that are not included in the complex numbers may be constructed from the real numbers in a way that generalize the construction of the complex numbers. They are sometimes called hypercomplex numbers. They include the quaternions H, introduced by Sir William Rowan Hamilton, in which multiplication is not commutative, the octonions, in which multiplication is not associative in addition to not being commutative, and the sedenions, in which multiplication is not alternative, neither associative nor commutative.
Transfinite numbers - For dealing with infinite sets, the natural numbers have been generalized to the ordinal numbers and to the cardinal numbers. The former gives the ordering of the set, while the latter gives its size. For finite sets, both ordinal and cardinal numbers are identified with the natural numbers. In the infinite case, many ordinal numbers correspond to the same cardinal number.
For dealing with infinite sets, the natural numbers have been generalized to the ordinal numbers and to the cardinal numbers. The former gives the ordering of the set, while the latter gives its size. For finite sets, both ordinal and cardinal numbers are identified with the natural numbers. In the infinite case, many ordinal numbers correspond to the same cardinal number.
Superreal and surreal numbers extend the real numbers by adding infinitesimally small numbers and infinitely large numbers, but still form fields.
Prime number Positive integer with exactly two divisors, 1 and itself
Scalar (mathematics) Elements of a field, e.g. real numbers, in the context of linear algebra
Notes - ^ "number, n." OED Online. Oxford University Press. Archived from the original on 2018-10-04. Retrieved 2017-05-16.
^ "number, n." OED Online. Oxford University Press. Archived from the original on 2018-10-04. Retrieved 2017-05-16.
^ In linguistics, a numeral can refer to a symbol like 5, but also to a word or a phrase that names a number, like "five hundred"; numerals include also other words representing numbers, like "dozen".
^ Matson, John. "The Origin of Zero". Scientific American. Archived from the original on 2017-08-26. Retrieved 2017-05-16.
^ a b Gilsdorf, Thomas E. Introduction to Cultural Mathematics: With Case Studies in the Otomies and Incas, John Wiley & Sons, Feb 24, 2012.
^ Restivo, S. Mathematics in Society and History, Springer Science & Business Media, Nov 30, 1992.
^ a b Ore, Oystein. Number Theory and Its History, Courier Dover Publications.
^ Chrisomalis, Stephen (2003-09-01). "The Egyptian origin of the Greek alphabetic numerals". Antiquity. 77 (297): 48596. doi:10.1017/S0003598X00092541. ISSN 0003-598X.
^ a b Bulliet, Richard; Crossley, Pamela; Headrick, Daniel; Hirsch, Steven; Johnson, Lyman (2010). The Earth and Its Peoples: A Global History, Volume 1. Cengage Learning. p. 192. ISBN 978-1-4390-8474-8. Archived from the original on 2017-01-28. Retrieved 2017-05-16. Indian mathematicians invented the concept of zero and developed the "Arabic" numerals and system of place-value notation used in most parts of the world today[better source needed]
^ Marshak, A., The Roots of Civilisation; Cognitive Beginnings of Mans First Art, Symbol and Notation, (Weidenfeld & Nicolson, London: 1972), 81ff.
^ Selin, Helaine, ed. (2000). Mathematics across cultures: the history of non-Western mathematics. Kluwer Academic Publishers. p. 451. ISBN 0-7923-6481-3.
^ Bernard Frischer (1984). "Horace and the Monuments: A New Interpretation of the Archytas Ode". In D.R. Shackleton Bailey (ed.). Harvard Studies in Classical Philology. Harvard University Press. p. 83. ISBN 0-674-37935-7.
References - Tobias Dantzig, Number, the language of science; a critical survey written for the cultured non-mathematician, New York, The Macmillan Company, 1930.[ISBN missing]
Tobias Dantzig, Number, the language of science; a critical survey written for the cultured non-mathematician, New York, The Macmillan Company, 1930.[ISBN missing]
Leo Cory, A Brief History of Numbers, Oxford University Press, 2015, ISBN 978-0-19-870259-7.
preposition - (used to indicate distance or direction from, separation, deprivation, etc.): within a mile of the church; south of Omaha; to be robbed of one's money.
(used to indicate distance or direction from, separation, deprivation, etc.): within a mile of the church; south of Omaha; to be robbed of one's money.
(used to indicate derivation, origin, or source): a man of good family; the plays of Shakespeare; a piece of cake.
(used to indicate cause, motive, occasion, or reason): to die of hunger.
(used to indicate material, component parts, substance, or contents): a dress of silk; an apartment of three rooms; a book of poems; a package of cheese.
(used to indicate apposition or identity): Is that idiot of a salesman calling again?
(used to indicate specific identity or a particular item within a category): the city of Chicago; thoughts of love.
(used to indicate possession, connection, or association): the king of France; the property of the church.
(used to indicate inclusion in a number, class, or whole): one of us.
(used to indicate the objective relation, the object of the action noted by the preceding noun or the application of a verb or adjective):the ringing of bells; He writes her of home; I'm tired of working.
(used to indicate reference or respect): There is talk of peace.
(used to indicate qualities or attributes): an ambassador of remarkable tact.
(used to indicate a specified time): They arrived of an evening.
Chiefly Northern U.S. before the hour of; until: twenty minutes of five.
on the part of: It was very mean of you to laugh at me.
Archaic. by: consumed of worms. - SEE MORESEE LESS
SEE MORESEE LESS - QUIZZES
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Origin of of
Origin of of - 1
1 - before 900; Middle English, Old English: of, off; cognate with German ab,Latin ab,Greek ap.See off, a-2, o'
before 900; Middle English, Old English: of, off; cognate with German ab,Latin ab,Greek ap.See off, a-2, o'
usage note for of - Of is sometimes added to phrases beginning with the adverb how or too followed by a descriptive adjective: How long of a drive will it be? It's too hot of a day for tennis. This construction is probably modeled on that in which how or too is followed by much, an unquestionably standard use in all varieties of speech and writing: How much of a problem will that cause the government? There was too much of an uproar for the speaker to be heard. The use of of with descriptive adjectives after how or too is largely restricted to informal speech. It occurs occasionally in informal writing and written representations of speech. See also couple, off.
Of is sometimes added to phrases beginning with the adverb how or too followed by a descriptive adjective: How long of a drive will it be? It's too hot of a day for tennis. This construction is probably modeled on that in which how or too is followed by much, an unquestionably standard use in all varieties of speech and writing: How much of a problem will that cause the government? There was too much of an uproar for the speaker to be heard. The use of of with descriptive adjectives after how or too is largely restricted to informal speech. It occurs occasionally in informal writing and written representations of speech. See also couple, off.
Definition for of (2 of 4) - auxiliary verb Nonstandard.
auxiliary verb Nonstandard. - Origin of of
Origin of of - 2
2 - A phonetic spelling representing the pronunciation of the word in continuous rapid speech
A phonetic spelling representing the pronunciation of the word in continuous rapid speech
usage note for of - Because the preposition of, when unstressed ( a piece of cake ), and the unstressed or contracted auxiliary verb have ( could have gone, could've gone ) are both pronounced [uhv] /v/ or [uh] // in connected speech, inexperienced writers commonly confuse the two words, spelling have as of ( I would of handed in my book report, but the dog ate it ). Professional writers have been able to exploit this spelling deliberately, especially in fiction, to help represent the speech of the uneducated: If he could of went home, he would of.
Because the preposition of, when unstressed ( a piece of cake ), and the unstressed or contracted auxiliary verb have ( could have gone, could've gone ) are both pronounced [uhv] /v/ or [uh] // in connected speech, inexperienced writers commonly confuse the two words, spelling have as of ( I would of handed in my book report, but the dog ate it ). Professional writers have been able to exploit this spelling deliberately, especially in fiction, to help represent the speech of the uneducated: If he could of went home, he would of.
Example sentences from the Web for of - We happily hoist our egg nog in the air, embrace each other, and raise our out-of-tune voices in song.
We happily hoist our egg nog in the air, embrace each other, and raise our out-of-tune voices in song.
DISH delivers a one-of-a-kind entertainment experience to every room of your home, wirelessly.
The company recently partnered with Oakley to create a one-of-a-kind single malt Scotch flask.
A much larger number are immediately separated from their infants, who are typically placed in some form of out-of-home care.
You never know when you are going to stumble upon a jewel in the most out-of-the-way corner.
But Lessard's a overbearin' son-of-a-gun all round, and he's always breakin' out in a new place.
Mr. Slocum was not educated in a university, and his life has been in by-paths, and out-of-the-way places.
The Spanish men-of-war, which were always painted white, had their colour changed to dark grey like the American ships.
Later on the commander of a German man-of-war and his staff were received and fted by the Captain-General.
British Dictionary definitions for of (1 of 2)
of - / (v, unstressed v) /
/ (v, unstressed v) / - preposition
preposition - used with a verbal noun or gerund to link it with a following noun that is either the subject or the object of the verb embedded in the gerundthe breathing of a fine swimmer (subject); the breathing of clean air (object)
used with a verbal noun or gerund to link it with a following noun that is either the subject or the object of the verb embedded in the gerundthe breathing of a fine swimmer (subject); the breathing of clean air (object)
used to indicate possession, origin, or associationthe house of my sister; to die of hunger
used after words or phrases expressing quantitiesa pint of milk
constituted by, containing, or characterized bya family of idiots; a rod of iron; a man of some depth
used to indicate separation, as in time or spacewithin a mile of the town; within ten minutes of the beginning of the concert
used to mark appositionthe city of Naples; a speech on the subject of archaeology
about; concerningspeak to me of love - used in passive constructions to indicate the agenthe was beloved of all
used in passive constructions to indicate the agenthe was beloved of all
informal used to indicate a day or part of a period of time when some activity habitually occursI go to the pub of an evening
US before the hour ofa quarter of nine - SEE MORESEE LESS
SEE MORESEE LESS - Word Origin for of
Word Origin for of - Old English (as prep and adv); related to Old Norse af, Old High German aba, Latin ab, Greek apo
Old English (as prep and adv); related to Old Norse af, Old High German aba, Latin ab, Greek apo
part - noun
noun - a portion or division of a whole that is separate or distinct; piece, fragment, fraction, or section; constituent: the rear part of the house;to glue the two parts together.
a portion or division of a whole that is separate or distinct; piece, fragment, fraction, or section; constituent: the rear part of the house;to glue the two parts together.
an essential or integral attribute or quality: a sense of humor is part of a healthy personality.
a section or division of a literary work.
a portion, member, or organ of an animal body.
any of a number of more or less equal quantities that compose a whole or into which a whole is divided: Use two parts sugar to one part cocoa.
a region, quarter, or district: a journey to foreign parts.
a quality or attribute establishing the possessor as a person of importance or superior worth: Being both a diplomat and a successful businesswoman, she is widely regarded as a woman of parts.
either of the opposing sides in a contest, question, agreement, etc.
the dividing line formed in separating the hair of the head and combing it in different directions.
a constituent piece of a machine or tool either included at the time of manufacture or set in place as a replacement for the original piece.
Music. - the written or printed matter extracted from the score that a single performer or section uses in the performance of concerted music: a horn part.
the written or printed matter extracted from the score that a single performer or section uses in the performance of concerted music: a horn part.
a section or division of a composition: the allegro part of the first movement.
participation, interest, or concern in something; role: The neighbors must have had some part in planning the surprise party.
a person's share in or contribution to some action; duty, function, or office: You must do your part if we're to finish by tonight.
a character or role acted in a play or sustained in real life.
to cut (one part) away from a piece, as an end from a billet.
to keep the surface of (a casting) separate from the sand of the mold.
Obsolete. to leave. - SEE MORESEE LESS
SEE MORESEE LESS - verb (used without object)
verb (used without object) - to be or become divided into parts; break or cleave: The oil tanker parted amidships.
to be or become divided into parts; break or cleave: The oil tanker parted amidships.
to go or come apart; separate, as two or more things.
to go apart from or leave one another, as persons: We'll part no more.
to be or become separated from something else (usually followed by from).
Nautical. to break or become torn apart, as a cable.
adjective - adverb
adverb - Verb Phrases
Verb Phrases - part with, to give up (property, control, etc.); relinquish: to part with one's money.
part with, to give up (property, control, etc.); relinquish: to part with one's money.
ANTONYMS FOR part - QUIZZES
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Idioms for part
Idioms for part - for one's part, as far as concerns one: For my part, you can do whatever you please.
for one's part, as far as concerns one: For my part, you can do whatever you please.
for the most part, with respect to the greatest part; on the whole; generally; usually; mostly: They are good students, for the most part.
in good part, - without offense; in a good-natured manner; amiably: She was able to take teasing in good part.
without offense; in a good-natured manner; amiably: She was able to take teasing in good part.
to a great extent; largely: His success is in good part ascribable to dogged determination.
in part, in some measure or degree; to some extent; partly; partially: The crop failure was due in part to unusual weather conditions.
on the part of, - so far as pertains to or concerns one: He expressed appreciation on the part of himself and his colleagues.
so far as pertains to or concerns one: He expressed appreciation on the part of himself and his colleagues.
as done or manifested by: attention on the part of the audience.
Also on one's part. - part and parcel, an essential, necessary, or integral part: Her love for her child was part and parcel of her life.
part and parcel, an essential, necessary, or integral part: Her love for her child was part and parcel of her life.
part company, - to bid farewell or go separate ways; leave one another.
to bid farewell or go separate ways; leave one another.
to dissolve a personal affiliation, relationship, etc., especially because of irreconcilable differences.
to disagree. - take part, to participate; share or partake: They refused to take part in any of the activities of the community.
take part, to participate; share or partake: They refused to take part in any of the activities of the community.
take someone's part, to align oneself with; side with; champion; back: His parents took his part, even though he was obviously in the wrong.
SEE MORE IDIOMSSEE FEWER IDIOMS -
Origin of part - First recorded before 1000; (noun) Middle English (from Old French, from Latin ), Old English, from Latin part- (stem of pars ) piece, portion; (verb) Middle English parten, from Old French partir, from Latin partre, derivative of pars
First recorded before 1000; (noun) Middle English (from Old French, from Latin ), Old English, from Latin part- (stem of pars ) piece, portion; (verb) Middle English parten, from Old French partir, from Latin partre, derivative of pars
synonym study for part - 1. Part, piece, portion, segment, section, fraction, fragment refer to something that is less than the whole. Part is the general word: part of a house. A piece suggests a part which is itself a complete unit or it may mean an irregular fragment: a piece of pie; a piece of a broken vase. A portion is a part allotted or assigned to a person, purpose, etc.: a portion of food. A segment is often a part into which something separates naturally: a segment of an orange. Section suggests a relatively substantial, clearly separate part that fits closely with other parts to form a whole: a section of a fishing rod, a book. Fraction suggests a less substantial but still clearly delimited part, often separate from other parts: a fraction of his former income. Fragment suggests a broken, inconsequential, incomplete part, with irregular or imprecise outlines or boundaries: a fragment of broken pottery, of information.
1. Part, piece, portion, segment, section, fraction, fragment refer to something that is less than the whole. Part is the general word: part of a house. A piece suggests a part which is itself a complete unit or it may mean an irregular fragment: a piece of pie; a piece of a broken vase. A portion is a part allotted or assigned to a person, purpose, etc.: a portion of food. A segment is often a part into which something separates naturally: a segment of an orange. Section suggests a relatively substantial, clearly separate part that fits closely with other parts to form a whole: a section of a fishing rod, a book. Fraction suggests a less substantial but still clearly delimited part, often separate from other parts: a fraction of his former income. Fragment suggests a broken, inconsequential, incomplete part, with irregular or imprecise outlines or boundaries: a fragment of broken pottery, of information.
Words related to part - Example sentences from the Web for part
Example sentences from the Web for part - Added to drinking water at concentrations of around one part per million, fluoride ions stick to dental plaque.
Added to drinking water at concentrations of around one part per million, fluoride ions stick to dental plaque.
Music is a huge part of the tone of Black Dynamite overallgoing back to the original 2009 movie on which the series is based.
For his part, Bratton is disappointed but not surprised that the same narrative is already being mapped onto Fry and Spencer.
The third suspect, an 18-year-old named Hamyd Mourad, who turned himself in, is part of the same extended family.
On the upper part of the stem the whorls are very close together, but they are more widely separated at the lower portion.
The countries about the eastern part of the Mediterranean Sea and its adjoining waters.
To see a part of my scheme, from which I had hoped so much, go wrong before my eyes is maddening!
Thanks to Berthier's admirable system, Bonaparte was kept in touch with every part of his command.
Nothing but an extreme love of truth could have hindered me from concealing this part of my story.
British Dictionary definitions for part (1 of 2)
noun - an integral constituent of somethingdancing is part of what we teach
an integral constituent of somethingdancing is part of what we teach
an amount less than the whole; bitthey only recovered part of the money
(as modifier)an old car in part exchange for a new one
one of several equal or nearly equal divisionsmix two parts flour to one part water
an actor's role in a play - the speech and actions which make up such a role
the speech and actions which make up such a role
a written copy of these - a person's proper role or dutyeveryone must do his part
a person's proper role or dutyeveryone must do his part
(often plural) region; areayou're well known in these parts
anatomy any portion of a larger structure - a component that can be replaced in a machine, engine, etcspare parts
a component that can be replaced in a machine, engine, etcspare parts
US, Canadian and Australian the line of scalp showing when sections of hair are combed in opposite directionsBritish equivalent: parting
music - one of a number of separate melodic lines making up the texture of music
one of a number of separate melodic lines making up the texture of music
one of such melodic lines, which is assigned to one or more instrumentalists or singersthe viola part; the soprano solo part
such a line performed from a separately written or printed copySee part song
(foll by in) to have something to do (with); be instrumental (in)to play a part in the king's downfall
take in good part to respond to (teasing) with good humour
take part in to participate in - take someone's part to support someone in an argument
take someone's part to support someone in an argument
SEE MORESEE LESS - verb
verb - to divide or separate from one another; take or come apartto part the curtains; the seams parted when I washed the dress
to divide or separate from one another; take or come apartto part the curtains; the seams parted when I washed the dress
to go away or cause to go away from one another; stop or cause to stop seeing each otherthe couple parted amicably
(intr foll by from) to leave; say goodbye (to)
(intr foll by with) to relinquish, esp reluctantlyI couldn't part with my teddy bear
(tr foll by from) to cause to relinquish, esp reluctantlyhe's not easily parted from his cash
(intr) to split; separatethe path parts here
(tr) to arrange (the hair) in such a way that a line of scalp is left showing
to end a friendship or association, esp as a result of a quarrel; separatethey were in partnership, but parted company last year
(foll by with) to leave; go away from; be separated from
Medical definitions for part - part
part - [ prt ]
[ prt ] - n.
n. - A portion, division, piece, or segment of a whole.
A portion, division, piece, or segment of a whole.
Any of several equal portions or fractions that can constitute a whole or into which a whole can be divided.
An organ, member, or other division of an organism.
Pattern (architecture) - Pattern in architecture is the idea of capturing architectural design ideas as archetypal and reusable descriptions. The term pattern in this context is usually attributed to Christopher Alexander,[1] an Austrian born American architect. The patterns serve as an aid to design cities and buildings. The concept of having collections of "patterns", or typical samples as such, is much older. One can think of these collections as forming a pattern language, whereas the elements of this language may be combined, governed by certain rules.
Pattern in architecture is the idea of capturing architectural design ideas as archetypal and reusable descriptions. The term pattern in this context is usually attributed to Christopher Alexander,[1] an Austrian born American architect. The patterns serve as an aid to design cities and buildings. The concept of having collections of "patterns", or typical samples as such, is much older. One can think of these collections as forming a pattern language, whereas the elements of this language may be combined, governed by certain rules.
This may be distinct from common use of pattern books, which are collections of architectural plans which may be copied in new works.
Contents - Alexander's patterns seek to provide a source of proven ideas for individuals and communities to use in constructing their living and working environment. As such their aim is both aesthetic and political: to show how beautiful, comfortable and flexible built environments can be constructed, and to enable those people who will inhabit those environments to challenge any solution forced upon them.
Alexander's patterns seek to provide a source of proven ideas for individuals and communities to use in constructing their living and working environment. As such their aim is both aesthetic and political: to show how beautiful, comfortable and flexible built environments can be constructed, and to enable those people who will inhabit those environments to challenge any solution forced upon them.
A pattern records the design decisions taken by many builders in many places over many years in order to resolve a particular problem. Alexander describes a problem in terms of the so-called forces that act in it, and the solution is said to resolve those forces. If there are still unresolved forces, then additional patterns may be needed to balance these remaining forces.
Patterns may be collected together into a pattern language that addresses a particular domain. A large body of patterns was published by Alexander and his collaborators as A Pattern Language. The patterns in that book were intended to enable communities to construct and modify their own homes, workplaces, towns and cities.
Other than Alexander's own projects, few building projects have tried to use Alexander's patterns. Those that have done so have met a mixed response from other architects, builders, architectural critics, and users. Alexander has come to believe that patterns themselves are not enough, and that one needs a "morphogenetic" understanding of the formation of the built environment. He has published his ideas in the four-volume work The Nature of Order.
While the pattern language idea has so far had limited impact on the building industry, it has had a profound influence on many workers in the information technology industry.
Grabow, Stephen: Christopher Alexander: The Search for a New Paradigm in Architecture, Routledge & Kegan Paul, London and Boston, 1983.
Leitner, Helmut: Pattern Theory: Introduction and Perspectives on the Tracks of Christopher Alexander, Graz, 2015, ISBN 1505637430.
Oxford English and Spanish Dictionary, Synonyms, and Spanish to English Translator
Meaning of perimeter in English: - perimeter
perimeter - The continuous line forming the boundary of a closed geometrical figure.
The continuous line forming the boundary of a closed geometrical figure.
the perimeter of a rectangle - More example sentences
More example sentences - He compares the areas of figures with equal perimeters and volumes of solids with equal surface areas, proving a result due to Zenodorus that the sphere has greater volume than any regular solid with equal surface area.
He compares the areas of figures with equal perimeters and volumes of solids with equal surface areas, proving a result due to Zenodorus that the sphere has greater volume than any regular solid with equal surface area.
The number four, for example, would be the ratio of the perimeter of a square to one of its sides and also the ratio of the area of a square to the area of a square whose side is half the original.
Then these rings also have the additional property that both the inner perimeters are equal and the outer perimeters are equal.
Zenodorus studied the area of a figure with a fixed perimeter and the volume of a solid figure with fixed surface.
Answer: the arc lengths and, therefore, the perimeters are equal.
The perimeter of the inner polygon is shorter than the circumference of the circle, while that of the outer polygon is longer.
Finally, if the rope is short enough (less than half the perimeter of the barn), the problem simplifies immensely.
The most interesting results show, with a very ingenious proof, that an equilateral triangle has a greater area than any isosceles or scalene triangle with the same perimeter.
You calculate the perimeter by multiplying the diameter by pi.
It is easier to find a pentagon that circumscribes the same circle as the given square and has the same perimeter.
The square and the cube are abstract, they're mathematical forms, measurements, perimeters, boundaries, mental constructs, and as such, are emotionally unknowable.
We found that the area, perimeter, length, and width of the lamina were highly correlated, suggesting the existence of a common genetic control.
1.1The outermost parts or boundary of an area or object.
the perimeter of the garden - More example sentences
More example sentences - a perimeter fence
a perimeter fence - He said it was the landlord of the estate who had replaced the perimeter fence around the whole of the industrial area.
He said it was the landlord of the estate who had replaced the perimeter fence around the whole of the industrial area.
One is a low-voltage electric fence around the perimeter of your garden.
The only sure way of deterring them is to have an electric fence built around the perimeter of the garden.
There are lots of grasshoppers around here, but my hens patrol the garden perimeter fence and really reduce the numbers of insects in the garden.
A two-kilometre perimeter fence for the broader area is also planned.
Most styles can be adapted to meet any pool codes in your area, and provide a safe perimeter fence around your pool.
Sub-zero temperatures at the complex left the narrow perimeter roads covered in sheet ice, with virtually no grip for the opening cars.
They ran to a perimeter concrete fence and jumped over.
After dark I drove the perimeter road and saw more jackals and foxes.
The court heard how she made off with thousands of pounds worth of holidaymakers' property after scaling the perimeter fence and entering the rooms.
For the less energetic, there is a walk around the perimeter racecourse road beginning at 2 pm.
I drove around our perimeter road one rainy night and saw lots of little rodents of some type running around.
There were wooded areas beyond the perimeter and alongside one of the streams, but the course itself was mostly just a large empty field.
About 30 minutes after they had started out, they arrived just beyond the outer perimeter of the lab area.
Burn some sage, and walk the inner perimeter of your room or home if you can.
We could walk the entire perimeter of the island in less than an hour.
Surrounding the entire perimeter of the fence was a long line of barbed wire, spiky and foreboding.
A tough protein envelope surrounds the inner perimeter of the cell.
Repeat this until the entire perimeter of the room has been sanded.
Signs are being placed around airport perimeters urging them to join the cause.
1.2Basketball An area away from the basket, beyond the reach of the defensive team.
he was very patient in working the ball around the perimeter
More example sentences - That is to say, whenever the ball is on the perimeter, 3 defensive players are between the player with the ball and basket.
That is to say, whenever the ball is on the perimeter, 3 defensive players are between the player with the ball and basket.
With reduced defensive contact on the perimeter, point guards can do their jobs with less harassment.
More than anything, the team needs his defense on the perimeter against more athletic swingmen.
The low post has two options as the ball moves around the perimeter.
He's also beginning to get a feel for the right time to squeeze off a tough shot and when to flick the ball out to the perimeter and restart.
2An instrument for measuring the extent and characteristics of a person's field of vision.
Origin - Late Middle English via Latin from Greek perimetros, based on peri- around + metron measure.
Late Middle English via Latin from Greek perimetros, based on peri- around + metron measure.
Are You Learning English? Here Are Our Top English Tips
R&R Insurance Blog - We have all found ourselves in the position of reviewing an MSB Building Valuation and comparing it to a building's current valuation on the policy. While the policy reflects the building valuation as replacement cost, the insurance policy actually responds providing a reconstruction cost. Whats the difference you ask?
We have all found ourselves in the position of reviewing an MSB Building Valuation and comparing it to a building's current valuation on the policy. While the policy reflects the building valuation as replacement cost, the insurance policy actually responds providing a reconstruction cost. Whats the difference you ask?
Replacement cost is defined as the cost to construct or replace an entire building with equal quality and construction. A replacement cost does not include site improvements, demolition, debris removal, fees, premium material costs and other costs associated with the construction process. Replacement cost also assumes that current building material, design or layout will be available and used.
Reconstruction cost is defined as the cost to replicate the building, at current construction prices, using the like kind and quality materials, construction standards, design, layout and quality. The MSB reconstruction cost includes additional expenses related to repair and restoration contractors fees, the construction process itself, the location of the property, demolition costs and debris removal. These factors create a valuation that is higher than a new construction.
A cost provided by a builder for new construction will not include items provided for and included as property items within the ISO Commercial Property form (CP0010). The MSB Rating system is programmed with these additional costs.
A serial number is a unique identifier assigned incrementally or sequentially to an item, to uniquely identify it.
Serial numbers need not be strictly numerical. They may contain letters and other typographical symbols, or may consist entirely of a character string.
Serial numbers identify otherwise identical individual units with many, obvious uses. Serial numbers are a deterrent against theft and counterfeit products, as they can be recorded, and stolen or otherwise irregular goods can be identified. Some items with serial numbers are automobiles, electronics, and appliances. Banknotes and other transferable documents of value bear serial numbers to assist in preventing counterfeiting and tracing stolen ones.
They are valuable in quality control, as once a defect is found in the production of a particular batch of product, the serial number will identify which units are affected.
Serial numbers may be used to identify individual physical or intangible objects (for example computer software or the right to play an online multiplayer game). The purpose and application is different. A software serial number, otherwise called a product key, is usually not embedded in the software, but is assigned to a specific user with a right to use the software. The software will function only if a potential user enters a valid product code. The vast majority of possible codes are rejected by the software. If an unauthorised user is found to be using the software, the legitimate user can be identified from the code. It is usually not impossible, however, for an unauthorised user to create a valid but unallocated code either by trying many possible codes, or reverse engineering the software; use of unallocated codes can be monitored if the software makes an Internet connection.
The term serial number is sometimes used for codes which do not identify a single instance of something. For example, the International Standard Serial Number or ISSN used on magazines, journals and other periodicals, an equivalent to the International Standard Book Number (ISBN) applied to books, is assigned to each periodical. It takes its name from the library science use of the word serial to mean a periodical.
Certificates and certificate authorities (CA) are necessary for widespread use of cryptography. These depend on applying mathematically rigorous serial numbers and serial number arithmetic, again not identifying a single instance of the content being protected.
The term serial number is also used in military formations as an alternative to the expression service number.[citation needed] In air forces, the serial number is used to uniquely identify individual aircraft and is usually painted on both sides of the aircraft fuselage, most often in the tail area, although in some cases the serial is painted on the side of the aircraft's fin/rudder(s). Because of this, the serial number is sometimes called a tail number.
In 2009, the U.S. FDA published draft guidance for the pharmaceutical industry to use serial numbers on prescription drug packages.[2] This measure is intended to enhance the traceability of drugs and to help prevent counterfeiting.
Serial numbers are often used in network protocols. However, most sequence numbers in computer protocols are limited to a fixed number of bits, and will wrap around after sufficiently many numbers have been allocated. Thus, recently allocated serial numbers may duplicate very old serial numbers, but not other recently allocated serial numbers. To avoid ambiguity with these non-unique numbers, RFC 1982 "Serial Number Arithmetic", defines special rules for calculations involving these kinds of serial numbers.
Lollipop sequence number spaces are a more recent and sophisticated scheme for dealing with finite-sized sequence numbers in protocols.
Elz, R., and R. Bush, RFC 1982 "Serial Number Arithmetic", Network Working Group, August 1996.
Plummer, William W. "Sequence Number Arithmetic". Cambridge, Massachusetts: Bolt Beranek and Newman, Inc., 21 September 1978.
Element of Design: Shape - Shape is a two dimesional area confined by a actual line or implied line (an edge for example). In drawing shapes are created when the ends of lines are joined to enclose areas.
Shape is a two dimesional area confined by a actual line or implied line (an edge for example). In drawing shapes are created when the ends of lines are joined to enclose areas.
Types of Shapes - There are two general categores that are use to describe shapes.Geometric and Free-Form or Organic Shapes
There are two general categores that are use to describe shapes.Geometric and Free-Form or Organic Shapes
Geometric Shapes - Can be described using mathematical terms
Can be described using mathematical terms - They are very regular or precise
They are very regular or precise - They are more often found in man-made things because they are easier to reproduce and make things with
They are more often found in man-made things because they are easier to reproduce and make things with
Examples of geometric shapes are: squares, rectangles, triangles, circles, oval, pentagons and so on.
Free-form or Organic Shapes - are difficult to describe using definitons
are difficult to describe using definitons - are irregular or uneven
are irregular or uneven - are more often found in nature
are more often found in nature - example coule include the shape of clouds, puddles, trees, leaves, rocks and so on.
example coule include the shape of clouds, puddles, trees, leaves, rocks and so on.
Positive and Negative Shapes - In most forms of art shapes may be considered positive or negative depending on how they are used. Positive shapes are usually those which are the subject matter withing a work of art. Negative shapes (or space) are those in the background or around the positive shapes. By viewing images as silohouettes, it is easier to understand what the positve shapes and the negative shapes are. See if you can identify the positive and negative shapes (space) in the silhouette images below
In most forms of art shapes may be considered positive or negative depending on how they are used. Positive shapes are usually those which are the subject matter withing a work of art. Negative shapes (or space) are those in the background or around the positive shapes. By viewing images as silohouettes, it is easier to understand what the positve shapes and the negative shapes are. See if you can identify the positive and negative shapes (space) in the silhouette images below
Size - "Physical dimension" redirects here. For the dimension of a physical quantity, see Dimension (physics).
"Physical dimension" redirects here. For the dimension of a physical quantity, see Dimension (physics).
A diagram comparing the size of an average human diver to the size of the modern great white shark, whale shark, and the prehistoric megalodon. The illustration also contains a linear measurement in meters in the middle.
A size comparison illustration comparing the sizes of various planets and stars. In each grouping after the first, the last object from the previous group is presented as the first object of the following group, to present a continuous sense of comparison.
A bat skull next to a ruler used to measure size. Size: 7 mm (0.28 in)
A finch egg next to a dime; a person familiar with the size of a dime would thereby have a sense of the size of the egg.
Forced perspective illusion wherein the perceived size of the Sphinx next to a human is distorted by the incomplete view of both, and the appearance of physical contact between the two.
This animation gives a sense of the scale of some of the known objects in our universe.
In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter".[1] Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches.
The sizes with which humans tend to be most familiar are body dimensions (measures of anthropometry), which include measures such as human height and human body weight. These measures can, in the aggregate, allow the generation of commercially useful distributions of products that accommodate expected body sizes,[2] as with the creation of clothing sizes and shoe sizes, and with the standardization of door frame dimensions, ceiling heights, and bed sizes. The human experience of size can lead to a psychological tendency towards size bias,[3] wherein the relative importance or perceived complexity of organisms and other objects is judged based on their size relative to humans, and particularly whether this size makes them easy to observe without aid.
Contents - Humans most frequently perceive the size of objects through visual cues.[4] One common means of perceiving size is to compare the size of a newly observed object with the size of a familiar object whose size is already known. Binocular vision gives humans the capacity for depth perception, which can be used to judge which of several objects is closer, and by how much, which allows for some estimation of the size of the more distant object relative to the closer object. The perception of size can be distorted by manipulating these cues, for example through the creation of forced perspective.
Humans most frequently perceive the size of objects through visual cues.[4] One common means of perceiving size is to compare the size of a newly observed object with the size of a familiar object whose size is already known. Binocular vision gives humans the capacity for depth perception, which can be used to judge which of several objects is closer, and by how much, which allows for some estimation of the size of the more distant object relative to the closer object. The perception of size can be distorted by manipulating these cues, for example through the creation of forced perspective.
Some measures of size may also be determined by sound. Visually impaired humans often use echolocation to determine features of their surroundings, such as the size of spaces and objects. However, even humans who lack this ability can tell if a space that they are unable to see is large or small from hearing sounds echo in the space. Size can also be determined by touch, which is a process of haptic perception.
The sizes of objects that can not readily be measured merely by sensory input may be evaluated with other kinds of measuring instruments. For example, objects too small to be seen with the naked eye may be measured when viewed through a microscope, while objects too large to fit within the field of vision may be measured using a telescope, or through extrapolation from known reference points. However, even very advanced measuring devices may still present a limited field of view.
Objects being described by their relative size are often described as being comparatively big and little, or large and small, although "big and little tend to carry affective and evaluative connotations, whereas large and small tend to refer only to the size of a thing".[5] A wide range of other terms exist to describe things by their relative size, with small things being described for example as tiny, miniature, or minuscule, and large things being described as, for example, huge, gigantic, or enormous. Objects are also typically described as tall or short specifically relative to their vertical height, and as long or short specifically relative to their length along other directions.
Although the size of an object may be reflected in its mass or its weight, each of these is a different concept. In scientific contexts, mass refers loosely to the amount of "matter" in an object (though "matter" may be difficult to define), whereas weight refers to the force experienced by an object due to gravity.[6] An object with a mass of 1.0 kilogram will weigh approximately 9.81 newtons (newton is the unit of force, while kilogram is the unit of mass) on the surface of the Earth (its mass multiplied by the gravitational field strength). Its weight will be less on Mars (where gravity is weaker), more on Saturn, and negligible in space when far from any significant source of gravity, but it will always have the same mass. Two objects of equal size, however, may have very different mass and weight, depending on the composition and density of the objects. By contrast, if two objects are known to have roughly the same composition, then some information about the size of one can be determined by measuring the size of the other, and determining the difference in weight between the two. For example, if two blocks of wood are equally dense, and it is known that one weighs ten kilograms and the other weighs twenty kilograms, and that the ten kilogram block has a volume of one cubic foot, then it can be deduced that the twenty kilogram block has a volume of two cubic feet.
The concept of size is often applied to ideas that have no physical reality. In mathematics, magnitude is the size of a mathematical object, which is an abstract object with no concrete existence. Magnitude is a property by which the object can be compared as larger or smaller than other objects of the same kind. More formally, an object's magnitude is an ordering (or ranking) of the class of objects to which it belongs. There are various other mathematical concepts of size for sets, such as:
cardinality (equal if there is a bijection), of a set is a measure of the "number of elements of the set"
for well-ordered sets: ordinal number (equal if there is an order-isomorphism)
In statistics (hypothesis testing), the "size" of the test refers to the rate of false positives, denoted by . In astronomy, the magnitude of brightness or intensity of a star is measured on a logarithmic scale. Such a scale is also used to measure the intensity of an earthquake, and this intensity is often referred to as the "size" of the event.[7] In computing, file size is a measure of the size of a computer file, typically measured in bytes. The actual amount of disk space consumed by the file depends on the file system. The maximum file size a file system supports depends on the number of bits reserved to store size information and the total size of the file system in terms of its capacity to store bits of information.
In poetry, fiction, and other literature, size is occasionally assigned to characteristics that do not have measurable dimensions, such as the metaphorical reference to the size of a person's heart as a shorthand for describing their typical degree of kindness or generosity. With respect to physical size, the concept of resizing is occasionally presented in fairy tales, fantasy, and science fiction, placing humans in a different context within their natural environment by depicting them as having physically been made exceptionally large or exceptionally small through some fantastic means.
^ C. Smoryski, History of Mathematics: A Supplement (2008), p. 76.
^ Thomas T. Samaras, Human Body Size and the Laws of Scaling (2007), p. 3.
^ Clifford N. Matthews, Roy Abraham Varghese, Cosmic Beginnings and Human Ends: Where Science and Religion Meet (2995), p. 208: "The notion that bacteria are primitive, unsophisticated organisms stems from what I would call size chauvinism".
^ Bennett L. Schwartz, John H. Krantz, Sensation and Perception (2015), Chapter 7: "Depth and Size Perception", p. 169-199.
^ John R. Taylor, The Mental Corpus: How Language is Represented in the Mind (2012), p. 108.
^ See, e.g., Robert A. Meyers, Extreme Environmental Events: Complexity in Forecasting and Early Warning (2010), p. 364, stating "[t]he corner frequency scales with the size of the earthquake measured by the seismic moment".
In information systems, a tag is a keyword or term assigned to a piece of information (such as an Internet bookmark, digital image, database record, or computer file). This kind of metadata helps describe an item and allows it to be found again by browsing or searching.[1] Tags are generally chosen informally and personally by the item's creator or by its viewer, depending on the system, although they may also be chosen from a controlled vocabulary.
People use tags to aid classification, mark ownership, note boundaries, and indicate online identity. Tags may take the form of words, images, or other identifying marks. An analogous example of tags in the physical world is museum object tagging. People were using textual keywords to classify information and objects long before computers. Computer based search algorithms made the use of such keywords a rapid way of exploring records.
Tagging gained popularity due to the growth of social bookmarking, image sharing, and social networking websites.[2] These sites allow users to create and manage labels (or "tags") that categorize content using simple keywords. Websites that include tags often display collections of tags as tag clouds,[5] as do some desktop applications.[6] On websites that aggregate the tags of all users, an individual user's tags can be useful both to them and to the larger community of the website's users.
Tagging systems have sometimes been classified into two kinds: top-down and bottom-up.[3]:142[4]:24 Top-down taxonomies are created by an authorized group of designers (sometimes in the form of a controlled vocabulary), whereas bottom-up taxonomies (called folksonomies) are created by all users.[3]:142 This definition of "top down" and "bottom up" should not be confused with the distinction between a single hierarchical tree structure (in which there is one correct way to classify each item) versus multiple non-hierarchical sets (in which there are multiple ways to classify an item); the structure of both top-down and bottom-up taxonomies may be either hierarchical, non-hierarchical, or a combination of both.[3]:142143 Some researchers and applications have experimented with combining hierarchical and non-hierarchical tagging to aid in information retrieval.[7][8][9] Others are combining top-down and bottom-up tagging,[10] including in some large library catalogs (OPACs) such as WorldCat.[11][12]:74[13][14]
Metadata tags as described in this article should not be confused with the use of the word "tag" in some software to refer to an automatically generated cross-reference; examples of the latter are tags tables in Emacs[15] and smart tags in Microsoft Office.[16]
The use of keywords as part of an identification and classification system long predates computers. Paper data storage devices, notably edge-notched cards, that permitted classification and sorting by multiple criteria were already in use prior to the twentieth century, and faceted classification has been used by libraries since the 1930s.
In the late 1970s and early 1980s, the Unix text editor Emacs offered a companion software program called Tags that could automatically build a table of cross-references called a tags table that Emacs could use to jump between a function call and that function's definition.[17] This use of the word "tag" did not refer to metadata tags, but was an early use of the word "tag" in software to refer to a word index.
Online databases and early websites deployed keyword tags as a way for publishers to help users find content. In the early days of the World Wide Web, the meta element was used by web designers to tell web search engines what the web page was about, but these keywords were only visible in a web page's source code and were not modifiable by users.
"A Description of the Equator and Some therLands", collaborative hypercinema portal, produced by documenta X, 1997. User upload page associating user contributed media with the term Tag.
In 1997, the collaborative portal "A Description of the Equator and Some therLands" produced by documenta X, Germany, used the folksonomic term Tag for its co-authors and guest authors on its Upload page.[18] In "The Equator" the term Tag for user-input was described as an abstract literal or keyword to aid the user. However, users defined singular Tags, and did not share Tags at that point.
In 2003, the social bookmarking website Delicious provided a way for its users to add "tags" to their bookmarks (as a way to help find them later);[2]:162 Delicious also provided browseable aggregated views of the bookmarks of all users featuring a particular tag.[19] Within a couple of years, the photo sharing website Flickr allowed its users to add their own text tags to each of their pictures, constructing flexible and easy metadata that made the pictures highly searchable.[20] The success of Flickr and the influence of Delicious popularized the concept,[21] and other social software websitessuch as YouTube, Technorati, and Last.fmalso implemented tagging.[22] In 2005, the Atom web syndication standard provided a "category" element for inserting subject categories into web feeds, and in 2007 Tim Bray proposed a "tag" URN.[23]
Many systems (and other web content management systems) allow authors to add free-form tags to a post, along with (or instead of) placing the post into a predetermined category.[5] For example, a post may display that it has been tagged with and . Each of those tags is usually a web link leading to a index page listing all of the posts associated with that tag. The blog may have a sidebar listing all the tags in use on that blog, with each tag leading to an index page. To reclassify a post, an author edits its list of tags. All connections between posts are automatically tracked and updated by the blog software; there is no need to relocate the page within a complex hierarchy of categories.
An official tag is a keyword adopted by events and conferences for participants to use in their web publications, such as blog entries, photos of the event, and presentation slides.[33] Search engines can then index them to make relevant materials related to the event searchable in a uniform way. In this case, the tag is part of a controlled vocabulary.
A researcher may work with a large collection of items (e.g. press quotes, a bibliography, images) in digital form. If he/she wishes to associate each with a small number of themes (e.g. to chapters of a book, or to sub-themes of the overall subject), then a group of tags for these themes can be attached to each of the items in the larger collection.[34] In this way, freeform classification allows the author to manage what would otherwise be unwieldy amounts of information.[35]
A triple tag or machine tag uses a special syntax to define extra semantic information about the tag, making it easier or more meaningful for interpretation by a computer program.[36] Triple tags comprise three parts: a namespace, a predicate, and a value. For example, is a tag for the geographical longitude coordinate whose value is 50.123456. This triple structure is similar to the Resource Description Framework model for information.
The triple tag format was first devised for geolicious in November 2004,[37] to map Delicious bookmarks, and gained wider acceptance after its adoption by Mappr and GeoBloggers to map Flickr photos.[38] In January 2007, Aaron Straup Cope at Flickr introduced the term machine tag as an alternative name for the triple tag, adding some questions and answers on purpose, syntax, and use.[39]
Specialized metadata for geographical identification is known as geotagging; machine tags are also used for other purposes, such as identifying photos taken at a specific event or naming species using binomial nomenclature.[40]
A knowledge tag is a type of meta-information that describes or defines some aspect of a piece of information (such as a document, digital image, database table, or web page).[41] Knowledge tags are more than traditional non-hierarchical keywords or terms; they are a type of metadata that captures knowledge in the form of descriptions, categorizations, classifications, semantics, comments, notes, annotations, hyperdata, hyperlinks, or references that are collected in tag profiles (a kind of ontology).[41] These tag profiles reference an information resource that resides in a distributed, and often heterogeneous, storage repository.[41]
Knowledge tags are part of a knowledge management discipline that leverages Enterprise 2.0 methodologies for users to capture insights, expertise, attributes, dependencies, or relationships associated with a data resource.[3]:251[42] Different kinds of knowledge can be captured in knowledge tags, including factual knowledge (that found in books and data), conceptual knowledge (found in perspectives and concepts), expectational knowledge (needed to make judgments and hypothesis), and methodological knowledge (derived from reasoning and strategies).[42] These forms of knowledge often exist outside the data itself and are derived from personal experience, insight, or expertise. Knowledge tags are considered an expansion of the information itself that adds additional value, context, and meaning to the information. Knowledge tags are valuable for preserving organizational intelligence that is often lost due to turnover, for sharing knowledge stored in the minds of individuals that is typically isolated and unharnessed by the organization, and for connecting knowledge that is often lost or disconnected from an information resource.[43]
In a typical tagging system, there is no explicit information about the meaning or semantics of each tag, and a user can apply new tags to an item as easily as applying older tags.[2] Hierarchical classification systems can be slow to change, and are rooted in the culture and era that created them; in contrast, the flexibility of tagging allows users to classify their collections of items in the ways that they find useful, but the personalized variety of terms can present challenges when searching and browsing.
When users can freely choose tags (creating a folksonomy, as opposed to selecting terms from a controlled vocabulary), the resulting metadata can include homonyms (the same tags used with different meanings) and synonyms (multiple tags for the same concept), which may lead to inappropriate connections between items and inefficient searches for information about a subject.[44] For example, the tag "orange" may refer to the fruit or the color, and items related to a version of the Linux kernel may be tagged "Linux", "kernel", "Penguin", "software", or a variety of other terms. Users can also choose tags that are different inflections of words (such as singular and plural),[45] which can contribute to navigation difficulties if the system does not include stemming of tags when searching or browsing. Larger-scale folksonomies address some of the problems of tagging, in that users of tagging systems tend to notice the current use of "tag terms" within these systems, and thus use existing tags in order to easily form connections to related items. In this way, folksonomies may collectively develop a partial set of tagging conventions.
Despite the apparent lack of control, research has shown that a simple form of shared vocabulary emerges in social bookmarking systems. Collaborative tagging exhibits a form of complex systems dynamics (or self-organizing dynamics).[46] Thus, even if no central controlled vocabulary constrains the actions of individual users, the distribution of tags converges over time to stable power law distributions.[46] Once such stable distributions form, simple folksonomic vocabularies can be extracted by examining the correlations that form between different tags. In addition, research has suggested that it is easier for machine learning algorithms to learn tag semantics when users tag "verbosely"when they annotate resources with a wealth of freely associated, descriptive keywords.[47]
Tagging systems open to the public are also open to tag spam, in which people apply an excessive number of tags or unrelated tags to an item (such as a YouTube video) in order to attract viewers. This abuse can be mitigated using human or statistical identification of spam items.[48] The number of tags allowed may also be limited to reduce spam.
Some tagging systems provide a single text box to enter tags, so to be able to tokenize the string, a separator must be used. Two popular separators are the space character and the comma. To enable the use of separators in the tags, a system may allow for higher-level separators (such as quotation marks) or escape characters. Systems can avoid the use of separators by allowing only one tag to be added to each input widget at a time, although this makes adding multiple tags more time-consuming.
A syntax for use within HTML is to use the rel-tag microformat which uses the rel attribute with value "tag" (i.e., ) to indicate that the linked-to page acts as a tag for the current context.[49]
^ a b For example: Leap is a macOS application that features a clickable tag cloud of macOS tags: Hampton-Smith, Sam (12 April 2013). "The pro designer's guide to photo organization". creativebloq.com. Archived from the original on 16 April 2013. Retrieved 10 March 2017. As with all the other options here, meta data can be added to individual files to help improve their find-ability, and uniquely the tag cloud field within Leap's interface allows you to quickly drill down to individually labelled files without fuss. TaggTool is a Windows application that permits tagging files and displaying a tag cloud: Henry, Alan (28 April 2010). "TaggTool: organize your files by keyword". pcmag.com. PC Magazine. Archived from the original on 11 July 2015. Retrieved 10 March 2017.
^ Carcillo, Franco; Rosati, Luca (2007). "Tags for citizens: integrating top-down and bottom-up classification in the Turin municipality website". In Schuler, Douglas (ed.). Online communities and social computing: second international conference, OCSC 2007, held as part of HCI International 2007, Beijing, China, July 2227, 2007: proceedings. 4564. Berlin; New York: Springer-Verlag. pp. 256264. doi:10.1007/978-3-540-73257-0_29. ISBN 9783540732563. OCLC 184906067.
^ Gerolimos, Michalis (January 2013). "Tagging for libraries: a review of the effectiveness of tagging systems for library catalogs". Journal of Library Metadata. 13 (1): 3658. doi:10.1080/19386389.2013.778730. S2CID 62681953.
^ Raman, T. V. (1997). Auditory user interfaces: toward the speaking computer. Boston: Kluwer Academic Publishers. p. 107. doi:10.1007/978-1-4615-6225-2. ISBN 978-0792399841. OCLC 37109286. S2CID 34186988. Calling a function defined in one compilation unit from within another is analogous to cross references in large hypertext documents. By using tags tables, the Emacs environment enables the user to turn program source code into powerful hypertext documents.
^ Wempen, Faithe (2010). Teach yourself visually Microsoft Access 2010. Teach yourself visually. Indianapolis: John Wiley & Sons. p. 69. ISBN 9780470577653. OCLC 495271168. You can turn on smart tags for a field to make it easier to cross-reference data between the Access database and Microsoft Outlook (or another personal information and e-mail program) and the Web.
^ Meyrowitz, Norman; Dam, Andries (September 1982). "Interactive Editing Systems: Part II". ACM Computing Surveys. 14 (3): 353415 (366367). doi:10.1145/356887.356890. S2CID 16977965. EMACS is an M.I.T. display editor designed to be 'extensible, customizable, and self-documenting' [...] Another interesting facility for program editing is the TAGS package. The separate program TAGS builds a TAGS table containing the file name and position in that file in which each application program function is defined. This table is loaded into EMACS; specifying the command Meta, function name causes EMACS to select the appropriate file and go to the proper function definition within that file.
^ Garrett, Jesse James (4 August 2005). "An Interview with Flickr's Eric Costello". Tags were not in the initial version of Flickr. Stewart Butterfield wanted to add them. He liked the way they worked on del.icio.us, the social bookmarking application. We added very simple tagging functionality, so you could tag your photos, and then look at all your photos with a particular tag, or any one person's photos with a particular tag. Soon thereafter, users started telling us that what was really interesting about tagging was not just how you've tagged your photos, but how the whole Flickr community has been tagging photos. So we started seeing a lot of requests from users to be able to see a global view of the tagscape.
^ Cherp, Aleh (17 March 2011). "Tagging". macademic.org. Academic workflows on a Mac. Archived from the original on 30 April 2016. Retrieved 10 March 2017.
^ Straup Cope, Aaron (24 January 2007). "Machine tags". flickr.com. Archived from the original on 20 April 2016. Retrieved 10 March 2017.
In Image Processing, projection profile refers to projection of sum of hits/positives along an axis from bi-dimensional image. Projection profile method is majorly used for segmentation of text objects present inside text documents.
Solution: - Note: Projection profile is calculated for a thresholded image or binarized image where a thresholded image is a grayscale image with pixel values as 0 or 255. Image pixels are replaced by 1 and 0 for pixel values 0 and 255 respectively.
Note: Projection profile is calculated for a thresholded image or binarized image where a thresholded image is a grayscale image with pixel values as 0 or 255. Image pixels are replaced by 1 and 0 for pixel values 0 and 255 respectively.
Projection profile is calculated separately for different axis. Projection profile along vertical axis is called Vertical Projection profile. Vertical projection profile is calculated for every column as sum of all row pixel values inside the column. Horizontal Projection profile is the projection profile of a image along horizontal axis. Horizontal Projection profile is calculated for every row as sum of all column pixel values inside the row.
Code Implementation for Horizontal Projection Profile: - C++
C++ - Python3
Python3 - Output:
Output: - Code Implementation for Vertical Projection Profile:
Code Implementation for Vertical Projection Profile: - C++
C++ - Python3
Python3 - To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning Basic Level Course
To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning Basic Level Course
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A title is one or more words used before or after a person's name, in certain contexts. It may signify either generation, an official position, or a professional or academic qualification. In some languages, titles may be inserted between the first and last name (for example, Graf in German, Cardinal in Catholic usage (Richard Cardinal Cushing) or clerical titles such as Archbishop). Some titles are hereditary.
Honorific titles or styles of address, a phrase used to convey respect to the recipient of a communication, or to recognize an attribute such as:
Social Titles, prevalent among certain sections of society due to historic or other reasons.
Mx. - Nonbinary, gender-neutral (does not indicate gender)
Miss Formal title for unmarried women and for female children
Master For male children: Young boys were formerly addressed as "Master [first name]." This was the standard form for servants to use in addressing their employer's minor sons.
Maid Archaic: When used as a title before a name (and not as a general term for a young domestic worker housemaid girl), this was a way to denote an unmarried woman, such as the character Maid Marian.
Aunt, Auntie, or Uncle may be used as titles by nieces and nephews, or by children to adults whom they know.
Other titles are used for various reasons, such as to show aristocratic status or one's role in government, in a religious organization, or in a branch of the military.
Prince/Princess From the Latin princeps, meaning "first person" or "first citizen." The title was originally used by Augustus at the establishment of the Roman Empire to avoid the political risk of assuming the title Rex ("King") in what was technically still a republic. In modern times, the title is often given to the sons and daughters of ruling monarchs. Also a title of certain ruling monarchs under the Holy Roman Empire and its subsidiary territories until 1918 (still survives in Liechtenstein, and also in Monaco although that is elsewhere), and in Imperial Russia before 1917. The German title is Frst ("first"), a translation of the Latin term;[A] the equivalent Russian term is (knyaz).
Grand Duke/Grand Duchess - "Big; large" + Latin Dux (leader). A variant of "Archduke," used particularly in English translations Romanov Dynasty Russian titles. Also used in various Germanic territories until World War I. Still survives in Luxembourg.
Duke/Duchess - From the Latin Dux, a military title used in the Roman Empire, especially in its early Byzantine period when it designated the military commander for a specific zone.
Marquis or Marquess (the feminine equivalent is Marquise or Marchioness) from the French marchis, literally "ruler of a border area," (from Old French marche meaning "border"); exact English translation is "March Lord," or "Lord of the March."
Count/Countess - From the Latin comes meaning "companion." The word was used by the Roman Empire in its Byzantine period as an honorific with a meaning roughly equivalent to modern English "peer." It became the title of those who commanded field armies in the Empire, as opposed to "Dux" which commanded locally based forces.
Earl (used in the United Kingdom instead of Count, but the feminine equivalent is Countess) From the Germanic jarl, meaning "chieftain," the title was brought to the British Isles by the Anglo-Saxons and survives in use only there, having been superseded in Scandinavia and on the European continent.
Viscount/Viscountess - From the Latin vicarius (Deputy; substitute. Hence "vicar" and prefix "vice-") appended to Latin comes. Literally: "Deputy Count".
Baron/Baroness - From the Late Latin Baro, meaning "man, servant, soldier" the title originally designated the chief feudal tenant of a place, who was in vassalage to a greater lord.
In the United Kingdom, "Lord" and "Lady" are used as titles for members of the nobility. Unlike titles such as "Mr" and "Mrs", they are not used before first names except in certain circumstances, for example as courtesy titles for younger sons, etc., of peers. In Scotland "Lord of Parliament" and "Lady of Parliament" are the equivalents of Baron and Baroness in England.
Lord from Old English hlford, hlfweard, meaning, literally, "bread-keeper," from hlf ("bread") + weard ("guardian, keeper") and by extension husband, father, or chief. (From which comes modified titles such as First Sea Lord and Lord of the Manor.) The feminine equivalent is Lady from the related Old English hlfde meaning, literally, "bread-kneader", from hlf ("bread") + de ("maid"), and by extension wife, daughter, or mistress of the house. (From which comes First Lady, the anachronistic Second Lady, etc.)
Emperor/Empress From the Latin Imperator, meaning he/she who holds the authority to command (imperium).
King/Queen Derived from Old Norse/Germanic words. The original meaning of the root of "king" apparently meant "leader of the family" or "descendant of the leader of the family," and the original meaning of "queen," "wife." By the time the words came into English they already meant "ruler."
Tsar/Tsarina (Tsaritsa) Slavonic loan-word from Latin.
Leader From Old English ldan, meaning "to guide", derived from Old Norse and Germanic. The head of state of North Korea is titled Great Leader. The de facto head of state of Iran is titled Supreme Leader.
Chief - A variation of the English "Prince", used as the short form of the word "Chieftain" (except for in Scotland, where "Chieftain" is a title held by a titleholder subordinate to a chief). Generally used to refer to a recognised leader within a chieftaincy system. From this come the variations paramount chief, clan chief and village chief. The feminine equivalent is Chieftess.
There are normal baronies and sovereign baronies, a sovereign barony can be compared with a principality, however, this is an historical exception; sovereign barons no longer have a sovereign barony, but only the title and style
Popess The title of a character found in Tarot cards based upon the Pope on the Roman Catholic Church. As the Bishop of Rome is an office always forbidden to women there is no formal feminine of Pope, which comes from the Latin word papa (an affectionate form of the Latin for father). The mythical Pope Joan, who was reportedly a woman, is always referred to with the masculine title Pope, even when her female identity is known. Further, even if a woman were to become Bishop of Rome it is unclear if she would take the title Popess. A parallel might be drawn with the Anglican Communion, whose female clergy use the masculine titles of priest and bishop as opposed to priestess or bishopess. Nonetheless some European languages, along with English, have formed a feminine form of the word pope, such as the Italian papessa, the French papesse, the Portuguese papisa, and the German Ppstin.
Titles used by knights, dames, baronets and baronetesses[edit]
"Sir" and "Dame" differ from titles such as "Mr" and "Mrs" in that they can only be used before a person's first name, and not immediately before their surname.
Christian priests often have their names prefixed with a title similar to The Reverend.
Dr. Short for doctor, a title used by those with doctoral degrees, such as DPhil, MD, DO, DDS, PhD, EdD DCN, DBA, DNP, PharmD, DVM, and LLD. Those with JD degrees do not use this as a title.
Eur Ing - Short for European Engineer, an international professional qualification and title for highly qualified engineers used in over 32 European countries.
The names of shipboard officers, certain shipping line employees and Maritime Academy faculty/staff are preceded by their title when acting in performance of their duties.
Captain (nautical) ship's highest responsible officer acting on behalf of the ship's owner (Master) or a person who is responsible for the maintenance of the vessels of a shipping line, for their docking, the handling of cargo and for the hiring of personnel for deck departments (Port Captain).
Chief- a licensed mariner in charge of the engineering (Chief Engineer) or deck (Chief Mate or Officer) department
Mate- licensed member of the deck department of a merchant ship (see Second Mate & Third Mate)
Cadet unlicensed trainee mate/officer or engineer under training
The names of police officers may be preceded by a title such as "Officer" or by their rank.
In North America, several jurisdictions restrict the use of some professional titles to those individuals holding a valid and recognised license to practice. Individuals not authorised to use these reserved titles may be fined or jailed. Protected titles are often reserved to those professions that require a bachelor's degree[2] or higher and a state, provincial, or national license.
Some titles are used to show one's role or position in a society or organization.
Queen's Scout title conferred upon a scout upon achieving highest attainable award achievable in the Scouting movement
Queen's Guide title conferred upon a guide upon highest attainable award for members of the Girl Guiding movement
Some titles are used in English to refer to the position of people in foreign political systems
Titles used in Rajasthan and other neighbourhood states of India in honour of Rajputs(only):
Hukum- used in general for any Rajput. Also, as suffix after following.
Daata- used for highset man member of a Rajput family.
Note: Titles are seldom used in Sweden; people are usually referred to by their first name
"Dear Leader" and "Supreme Leader" referred to Kim Jong-il as chief of North Korea. The title now refers to his son and successor Kim Jong-un. ( , ch'inaehann jidoja)
The following are no longer officially in use, though some may be claimed by former regnal dynasties.
When a difference exists below, male titles are placed to the left and female titles are placed to the right of the slash.
Mirza, Persian/Iranian, Indian and Afghanistan and Tajikistan King
Beg (Begzada or Begzadi, son-daughter of Beg), Baig or Bey in Under Mirza & using King or Military title.
Patil meaning "head" or "chief" is an Indian title. The Patil is in effect the ruler of this territory as he was entitled to the revenues collected therefrom.
Phrabat Somdej Phrachaoyuhua King of Thailand (Siam), the title literally means "The feet of the Greatest Lord who is on the heads (of his subjects)" (This royal title does not refer directly to the king himself but to his feet, according to traditions.)
Raja Malaysia, Raja denotes royalty in Perak and certain Selangor royal family lineages, is roughly equivalent to Prince or Princess
Preah Karuna Preah Bat Smdech Preah Bromneath King of Cambodia Khmer, the title literally means "The feet of the Greatest Lord who is on the heads (of his subjects)" (This royal title doesn't refer directly to the king himself but to his feet, according to traditions.)
Aceh, Brunei, Java, Oman, Malaysia, Sultan is the title of seven (Johor, Kedah, Kelantan, Pahang, Perak, Selangor, and Terengganu) of the nine rulers of the Malay states.
Susuhanan the Indonesian princely state of Surakarta until its abolition
Tengku Malaysia, Indonesia, Tengku (also spelled Tunku in Johor, Negeri Sembilan, Kedah and Deli Sultanate of Indonesia is roughly equivalent to Prince or Princess
Wang (King) pre-Imperial China. In China, "king" is the usual translation for the term wang .
Wang States of Korea that did not have control over the entire peninsula.
Vuong States in Vietnam that did not control the entire realm.
Yang di-Pertuan Agong Monarch of Malaysia, elected each five years among the reigning Sultan of each Malaysian state
Grobrger/Grobrgerin (English: Grand Burgher) historical German title acquired or inherited by persons and family descendants of the ruling class in autonomous German-speaking cities and towns of Central Europe, origin under the Holy Roman Empire, ceased after 1919 along with all titles of German nobility.
Kaiser/Kaiserin Imperial rulers of Germany and of Austria-Hungary
Kniaz'/Knyaginya/Knez/Knjeginja (generally translated as "prince") Kievan Rus'/Serbia
R, R taithe, Ruiri, R ruireach, and Ard R King, local king, regional overking, (provincial) king of overkings, and High King in Gaelic Ireland, also Scotland
"Mo'i", normally translated as King, is a title used by Hawaiian monarchs since unification in 1810. The last person to hold that title was Queen Lili'uokalani.[citation needed]
Concubine (The Chinese imperial system, for instance, had a vastly complex hierarchy of titled concubines and wives to the emperor)
Seigneur (from which come Monsignor and the French common polite term Monsieur, equivalent to Mister)
^ Prince of Wales is a title granted, following an investiture, to the eldest son of the Sovereign of the United Kingdom he is not a monarch in his own right.
Oxford English and Spanish Dictionary, Synonyms, and Spanish to English Translator
Meaning of total in English: - total
total - Pronunciation /tt()l/
Pronunciation /tt()l/ - adjective
adjective - 1attributive Comprising the whole number or amount.
1attributive Comprising the whole number or amount. - a total cost of 4,000
a total cost of 4,000 - More example sentences
More example sentences - The cost of the steel and its heat treatment amounts generally to less than a quarter of the total cost of the whole tool.
The cost of the steel and its heat treatment amounts generally to less than a quarter of the total cost of the whole tool.
You can't predict with any accuracy the total amount of anything that the whole country's going to need.
The applicants' bill of costs is for a very large amount, with total fees of about $200,000.
It does not seem to me to be a good reason for keeping him out of some of his costs that you need time to work out the total amount.
The total cost of all hotel accommodation for the month amounted to 29,316.
You can put complementary fruit in as long as the total amount of fruit is 3 cups.
During the period of our ownership, the total cost of our new investment has amounted to over 30m.
Our total bid amounted to less than seven per cent of the total project costs.
This was agreed in principle, the amount being dependent on the total cost of the works.
Data are sampling-date percentages relative to the total amount of emerged or shed leaves during the whole year.
Point out that this means they won't have to come up with the entire total cost at one time.
The newsletter, released last week, showed this was the total amount of donations given to the hospice in lieu of gifts to the couple.
The total amount collected will be announced at a later date.
Across England, the total amount being earned from diversification projects now stands at 100m per year.
The total amount distributed to our nominated charities was 11,000.
Thus, the total amount is not even one-fifth of what they produce.
According to the figures the total amount of violent crime rose 11 per cent to more than 812,000 incidents.
The other aspect of this problem is that it is as much about the poor allocation of funds on the wrong priorities as it is about the total amount being spent.
As much as $180,000 has been cited as missing, with no official confirmation of the total amount.
The total amount raised will be announced when the fund closes.
Wilkinson is a desperately complex person, driven by a need for absolute perfection and total control in his life.
So the claim that there are conservatives who believe in some sort of absolute liberty is a total straw man.
Now the sort of response that you are offering is in absolute total contrast to everything that we have heard so far.
On the other hand, just as comparing intrinsic qualities is subjectively unrealistic, comparing absolutes is a total waste.
Like I say, it will go absolutely anywhere with total confidence, even dug-up Dublin city centre.
He praised toleration, yet he advocated an absolute sovereign with total power over intellectual matters.
Indeed, were I to find myself in that sort of position, I would prefer for a total stranger to do that to me, rather than a friend.
The match, eventually won by Pakistan, was completed in total silence in an empty stadium.
The rest of us can readily vouch for him as a man of total and absolute integrity, a friend above reproach.
Recently a total stranger insisted we were acquainted.
Are people we sort-of know, who are used to being on camera, inherently less interesting to watch and talk about than a bunch of total strangers?
She was afraid they would get themselves in trouble if they came to the court and the jury voted for acquittal - but the verdict was heard in total silence.
Capable of 80 mph in almost total silence, it was powered by 13 batteries.
I felt a tinge of pessimism as I passed by thousands of total strangers exchanging high-fives and hugs.
I wonder how well one would describe their next door neighbor or even their mother to a total stranger.
In the cells the prisoners were not allowed to speak at all (so there was total silence) and the rations were very low.
Where else would you see total strangers letting someone else use the bathrooms in their house?
She asked him where he was but there was just total silence.
During the day we were forced to sit in the cell (we couldn't lie down) in total silence.
Synonyms - complete, utter, absolute, thorough, perfect, downright, out-and-out, outright, thoroughgoing, all-out, sheer, positive, prize, rank, pure, dyed-in-the-wool, deep-dyed, real, consummate, veritable, unmitigated, unqualified, unadulterated, unalloyed, unconditional, unequivocal, full, unlimited, limitless, infinite, ultimate, through and through, in-depth
complete, utter, absolute, thorough, perfect, downright, out-and-out, outright, thoroughgoing, all-out, sheer, positive, prize, rank, pure, dyed-in-the-wool, deep-dyed, real, consummate, veritable, unmitigated, unqualified, unadulterated, unalloyed, unconditional, unequivocal, full, unlimited, limitless, infinite, ultimate, through and through, in-depth
noun - Total:the whole number or amount of something.
Total:the whole number or amount of something.
he scored a total of thirty-three points - More example sentences
More example sentences - in total, 200 people were interviewed
in total, 200 people were interviewed - In total he has worked in the Caribbean for a total of three years at various times during his career.
In total he has worked in the Caribbean for a total of three years at various times during his career.
In total with both actions, it could take five years and potentially longer.
In total, at the end of today, five people were sentenced to a total of 21 years.
Only four points were scored in total in that period and it was a relief to all when the final whistle was blown.
Turnout and vote totals won't be known for quite a while.
We may currently not have much in our aggregate totals of giving, but, into the future we are the alumni base for which the school will lean on.
Four thousand athletes in total will be turning out to represent them.
The resulting totals for each intron were then randomly resampled with replacement and a value of m was calculated from each resultant data set.
The top 64 bowlers roll nine more games, with totals from round one carrying over.
Forecasting is not accurate enough to support laws that set quantitative targets for budget totals.
Education in America is financed mostly by state and local governments, whose expenditures aren't even counted in these totals.
Votes are counted locally but the totals are calculated nationally, and seats in parliament are awarded in proportion to votes.
And in a recent win over St. Francis of Brooklyn, she scored a total of 23 points that was the game high.
Queen's forward Amy Goodall scored a total of 24 points in the affair, adding 6 rebounds.
He starred for this club Old Mill all year scoring a total of 36 goals.
In the final standings it was District Six scoring a total of 415 points.
It also won 17 silvers and one special silver award, scoring a total of 23 points.
The Waterford team have now scored a total of 14 goals in their three games played and they have conceded only one.
Over 500 runs were scored and only a total of seven wickets fell.
In competition, boulderers are scored on a total of five or six different climbs.
verbtotals, totalling, totalled; US totaling, totaled
[with object] - 1Amount in number to.
1Amount in number to. - they were left with debts totalling 6,260
they were left with debts totalling 6,260 - More example sentences
More example sentences - It has debts totalling hundreds of billions of dollars and there has been no investment in its infrastructure for more than 20 years.
It has debts totalling hundreds of billions of dollars and there has been no investment in its infrastructure for more than 20 years.
It also warned investors it had been hit by two bad debts totalling some 200,000.
At the end of 2001, net debt totaled some $2.60 trillion.
Yes, there is a big number for household debt, which totals $9.5 trillion.
Last year CAS dealt with more than 160,000 debt cases totalling 70 million, an increase of 10m on the previous year.
Surveys have suggested that graduates can expect to university with student loan, overdraft and other debts totalling between 10,000 and 15,000.
A North Yorkshire businessman has been banned from being a company director for eight years after he was involved in the running of three companies in succession that collapsed with debts totalling 1,428,000.
Figures released this week reveal that 15 million remains unspent in school bank accounts across Bradford district, while others struggle with debts totalling 7 million.
The Telegraph & Argus reported in November how unspent cash in some schools totalled 15 million, while others had debts totalling more than 7 million.
With the banks pressing for repayment of debts totalling 6m, Hughes needed some money quickly and had his eye on exploiting some land he had bought called Poppyfields, in Branton, Doncaster.
Never one to laugh at the misfortunes of others, it is upsetting, nay distressing to read that Leeds United Football Club may be forced into administration with debts totalling eighty-one million pounds.
The club, after all, have lost more than 20m in the past three years, despite last season's run to the UEFA Cup final, and have a debt totalling 17.8m.
The business had debts totalling more than $300 million, of which $23 million were owned to its former employees.
Chairman of the board Glen Boldy says the liquidator would sell assets - including the theatre in Chapel Street - to pay debts totalling 50,000.
Combined with a cut in big donations from private supporters the Labour party is facing a financial crisis, with debts totalling 12 million.
In order to qualify for debt relief, the HIPC Initiative requires a country to have a debt totalling more than 150 per cent of their annual exports.
He shares a university-owned Fulford flat, earns 10,000 a year and has student debts totalling 12,000.
Mr Dowd was bought in to the Southampton Road campus to help revive the troubled college, after revelations that it had debts totalling more than 1m.
The answer was a list of 21 countries with debts totalling over $4-billion.
It was one of several major debts which pushed the club into administration last summer with debts totalling about 36 million.
Synonyms - add up to, amount to, mount up to, come to, run to, make, correspond to, equal, work out as, number
add up to, amount to, mount up to, come to, run to, make, correspond to, equal, work out as, number
Overall scores are computed by totaling the number of critical endorsements the respondent has made.
Additionally, there was no difference in response rates if the partial and full responses are totaled.
Instead of scanning every item individually, an RFID till would simply total up every item in your shopping trolley as it approached.
So I took the trouble to total up the popular vote for the House this time.
One day you stop, total up the pennies and are surprised to learn how much you have saved.
The next step is to total up those monthly outgoings and make sure they fall within your net income.
Simply list and total up all the assets that you own in one column.
I finally get all the ornaments scanned and bagged and total up the purchase.
As the bloodiest century in human history drew to a close, historians began to total up the casualties.
We calculated a job satisfaction score by totalling the scores for all five statements: 20 or more represented a positive response, on average, to all statements, and we suggest that this shows a high level of satisfaction.
Both sides' scores are then totalled and if the game is being played for money, the side with the higher score wins an amount proportional to the difference in scores from the side with the lower score.
I parred the 18th hole, and as we sat sipping iced tea, I totalled my score and realized that I had shot 79.
After that round, the judges totalled the scores to come up with the final five.
A series of games is played, the deal passing to the right after each game and the scores are totalled.
On each turn, a player rolls a die as many times as he or she wishes, totaling the score of the rolls until the player decides to end the turn and pass the die to his or her opponent.
Each plan received an overall score that was calculated by totaling the score on all sections and dividing by six.
The number of challenges was totaled, and scores were categorized into two groups representing less than two or two or more parenting challenges.
The top four overall point-getters when the two scores are totaled up will comprise the women's team and represent the United States in these two international championships this fall.
Scores were totaled with scores of 6-7 as the cut-off points.
Now add up all your debts and total the minimum payments due on each.
Synonyms - add, sum, count, reckon, tot, compute, work out, take stock of
add, sum, count, reckon, tot, compute, work out, take stock of
2North American informal Damage (something, typically a vehicle) beyond repair; wreck.
More example sentences - he almost totalled the car
he almost totalled the car - And it appears to have totaled the vehicle, smashed in the back end and broke all the windows.
And it appears to have totaled the vehicle, smashed in the back end and broke all the windows.
Hull's vehicle was totaled and the train sustained $2,000 damage.
For a long time, even after I'd totaled two vehicles in collisions with deer, I continued to hold a similar view.
Our truck was totaled and the trailer was damaged enough to merit replacement.
However, if they have an accident and totaled their vehicle, the insurance company will only pay them the wholesale value of the vehicle.
After totaling the vehicle, not to mention about nine police cruisers (but somehow, not dying), he is sent to a prison in the middle of nowhere.
The vehicle was totaled, trapping the two occupants inside.
My friend was in a car injury last month and her car was totalled.
High-deductible health insurance operates the same way high-deductible auto insurance does: It does not pay for the equivalent of your oil change but does pay you when your car is totaled.
My wife was in her car, and she went through a fence and went down 70 feet, just straight down, and totaled the car, and she was able to be pulled out by the police.
You assume the car is totaled, even though you can't see what it looks like in front.
So, it's just a matter of time before I'm in my first accident that totals my car.
I used to be her taxi service, until she totaled my car doing donuts in a cul-de-sac.
Last May the two girls had been in a car accident together totaling Chelsea's car.
I am surprised I didn't get broken ribs like yourself, my car is totaled.
I had just turned 16 and, unfortunately with a number of other teenagers, I had just totaled my first car.
Because cars depreciate so rapidly, an accident that totals your car could leave you with a sizable chunk left to pay back to the bank.
She knew at those speeds she could easily smack into his back end and total both their cars.
His car is totalled and he, too, needs to get to court to prevent his wife from getting sole custody of his children and moving away.
But to her dismay, the car was totaled in an accident five months after she eliminated the debt.
Synonyms - wreck, crash, smash, destroy, damage beyond repair, demolish
wreck, crash, smash, destroy, damage beyond repair, demolish
Origin - Late Middle English via Old French from medieval Latin totalis, from totum the whole, neuter of Latin totus whole, entire. The verb, at first in the sense add up, dates from the late 16th century.
Late Middle English via Old French from medieval Latin totalis, from totum the whole, neuter of Latin totus whole, entire. The verb, at first in the sense add up, dates from the late 16th century.
Are You Learning English? Here Are Our Top English Tips
type - noun
noun - a number of things or persons sharing a particular characteristic, or set of characteristics, that causes them to be regarded as a group, more or less precisely defined or designated; class; category: a criminal of the most vicious type.
a number of things or persons sharing a particular characteristic, or set of characteristics, that causes them to be regarded as a group, more or less precisely defined or designated; class; category: a criminal of the most vicious type.
a thing or person regarded as a member of a class or category; kind; sort (usually followed by of): This is some type of mushroom.
Informal. a person, regarded as reflecting or typifying a certain line of work, environment, etc.: a couple of civil service types.
a thing or person that represents perfectly or in the best way a class or category; model: the very type of a headmaster.
Printing. - a rectangular piece or block, now usually of metal, having on its upper surface a letter or character in relief.
a rectangular piece or block, now usually of metal, having on its upper surface a letter or character in relief.
a genus or species that most nearly exemplifies the essential characteristics of a higher group.
the one or more specimens on which the description and naming of a species is based.
Agriculture. - the inherited features of an animal or breed that are favorable for any given purpose: dairy type.
the inherited features of an animal or breed that are favorable for any given purpose: dairy type.
a strain, breed, or variety of animal, or a single animal, belonging to a specific kind.
Logic, Linguistics.Also called type-word. the general form of a word, expression, symbol, or the like in contrast to its particular instances: The type and in red and white and blue has two separate tokens.Compare token (def. 8).
the pattern or model from which something is made.
an image or figure produced by impressing or stamping, as the principal figure or device on either side of a coin or medal.
a distinctive or characteristic mark or sign. - a symbol of something in the future, as an Old Testament event serving as a prefiguration of a New Testament event.
a symbol of something in the future, as an Old Testament event serving as a prefiguration of a New Testament event.
verb (used without object), typed, typing.
SYNONYMS FOR type - QUIZZES
QUIZZES - PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
PROVE YOUR POETIC PROWESS WITH THIS QUIZ ON POETRY TERMS
Shall we compare this quiz to a summer's day? Probably not, but it is a fun quest to see how informed you are on a wide range of poetry terms.
Question 1 of 7 - This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
This term means the "arrangement of words in regularly measured, patterned, or rhythmic lines or verses." What is it?
Meet Grammar Coach - Meet Grammar Coach
Meet Grammar Coach - Origin of type
Origin of type - First recorded in 142575; late Middle English: symbol, figure (from Middle French ), from Latin typus bas-relief, ground plan, from Greek tpos blow, impression
First recorded in 142575; late Middle English: symbol, figure (from Middle French ), from Latin typus bas-relief, ground plan, from Greek tpos blow, impression
usage note for type - 2. When preceded by a modifier, type meaning kind, sort is sometimes used without a following of: This type furnace uses very little current. In writing, a hyphen is often placed between type and the preceding word or words: a magnetic-type holder; a New England-type corn pudding. This construction is frequently criticized by usage guides; it is most typical of journalistic writing and advertising and occurs rarely in formal speech or writing. In almost all cases the construction can be rendered fully standard either by restoring of after type, with no hyphen ( this type of furnace; a New England type of corn pudding ) or by omitting type altogether ( a magnetic holder).
2. When preceded by a modifier, type meaning kind, sort is sometimes used without a following of: This type furnace uses very little current. In writing, a hyphen is often placed between type and the preceding word or words: a magnetic-type holder; a New England-type corn pudding. This construction is frequently criticized by usage guides; it is most typical of journalistic writing and advertising and occurs rarely in formal speech or writing. In almost all cases the construction can be rendered fully standard either by restoring of after type, with no hyphen ( this type of furnace; a New England type of corn pudding ) or by omitting type altogether ( a magnetic holder).
OTHER WORDS FROM type - mistype, verb, mistyped, mistyping.mistyped, adjectivepretype, verb (used with object), pretyped, pretyping.retype, verb (used with object), retyped, retyping.
mistype, verb, mistyped, mistyping.mistyped, adjectivepretype, verb (used with object), pretyped, pretyping.retype, verb (used with object), retyped, retyping.
untyped, adjectivewell-typed, adjective - SEE MORE RELATED FORMSSEE FEWER RELATED FORMS
SEE MORE RELATED FORMSSEE FEWER RELATED FORMS - Words nearby type
Words nearby type - Definition for type (2 of 2)
Definition for type (2 of 2) - -type
-type - a suffix representing type (prototype), especially in names of photographic processes: ferrotype.
a suffix representing type (prototype), especially in names of photographic processes: ferrotype.
VOCAB BUILDER - What is a basic definition of type?
What is a basic definition of type? - Type is used as a noun to mean a member of a category. As a verb type means to write using a typewriter or keyboard. The word type has many other senses as a noun and a verb.
Type is used as a noun to mean a member of a category. As a verb type means to write using a typewriter or keyboard. The word type has many other senses as a noun and a verb.
Type refers to something or someone that is a member of a category or class. Type is often followed with the word of and the category being referred to. For example, a German shepherd is a type of dog. The German shepherd is a member of the large group of animals known as dogs.
Real-life examples: Robins, pigeons, and eagles are types of birds. Hats, pants, and shirts are types of clothing. Vegetables, fruits, and meats are types of foods.
Used in a sentence: Martina likes only certain types of movies, such as comedies.
Informally, type is used in a similar sense to mean a person who has characteristics of a certain job, personality, or other quality.
Used in a sentence: We dont want any government types sniffing around our business.
As a verb, type means to write on a typewriter or keyboard. Now that typewriters are much less commonly used, type nearly always refers specifically to computer or cellphone keyboards.
Used in a sentence: I told him not to type a long, angry rant on his social media profile but he didnt listen.
Where does type come from? - The first records of type come from around 1425. It ultimately comes from Greek word tpos, meaning a blow or an impression.
The first records of type come from around 1425. It ultimately comes from Greek word tpos, meaning a blow or an impression.
How is type used in real life? - Type is a very common word that most often means to write on a keyboard or refers to something that is a member of a certain category.
Type is a very common word that most often means to write on a keyboard or refers to something that is a member of a certain category.
Words related to type - Example sentences from the Web for type
Example sentences from the Web for type - The algorithms used to compute a biological age for each of the different data typesas well as the AgeMetric scoring mechanismare either patented or patent-pending, Zhavoronkov said.
The algorithms used to compute a biological age for each of the different data typesas well as the AgeMetric scoring mechanismare either patented or patent-pending, Zhavoronkov said.
Now that the York team has identified the chemistry of human body odor, they can develop new types of deodorants, says Rudden.
However, this type of cell phone data can help agencies know how people behave as a storm approaches, perhaps giving them an opportunity to adjust their own approaches to evacuation orders, says Long.
I have to think her body type played a role, said Rachel Greenblatt, a Lecturer in Jewish Studies at Harvard University.
Sabrine was the outgoing, sociable type, and had many friends, while Ziad was shy and a little more introverted.
Though the average speaker is generally limited by one type of voice, which he varies somewhat, it is not often disguised.
Accustomed to a written character, their eyes became wearied by the crabbedness and formality of type.
True, she had never met the provincial type before, but she doubted if Rosewater had produced a crop of Isabel Otises.
I must make no mistake, and blunder into a national type of features, all wrong; if I make your mask, it must do us credit.
A mixed type of the present day Negro, she was slightly tall, and somewhat slender, with a figure straight and graceful.
British Dictionary definitions for type (1 of 2)
type - / (tap) /
/ (tap) / - noun
noun - a kind, class, or category, the constituents of which share similar characteristics
a kind, class, or category, the constituents of which share similar characteristics
a subdivision of a particular class of things or people; sortwhat type of shampoo do you use?
the general form, plan, or design distinguishing a particular group
informal a person who typifies a particular qualityhe's the administrative type
informal a person, esp of a specified kindhe's a strange type
a small block of metal or more rarely wood bearing a letter or character in relief for use in printing
such pieces collectively - characters printed from type; print
characters printed from type; print - biology
biology - the taxonomic group the characteristics of which are used for defining the next highest group, for example Rattus norvegicus (brown rat) is the type species of the rat genus Rattus
the taxonomic group the characteristics of which are used for defining the next highest group, for example Rattus norvegicus (brown rat) is the type species of the rat genus Rattus
linguistics a symbol regarded as standing for the class of all symbols identical to itCompare token (def. 8)
logic a class of expressions or of the entities they represent that can all enter into the same syntactic relations. The theory of types was advanced by Bertrand Russell to avoid the liar paradox, Russell's paradox, etc
philosophy a universal. If a sentence always has the same meaning whenever it is used, the meaning is said to be a property of the sentence-typeCompare token (def. 9)
mainly Christian theol a figure, episode, or symbolic factor resembling some future reality in such a way as to foreshadow or prefigure it
rare a distinctive sign or mark - SEE MORESEE LESS
SEE MORESEE LESS - verb
verb - to write (copy) on a typewriter
to write (copy) on a typewriter - (tr) to be a symbol of; typify
(tr) to be a symbol of; typify
(tr) to decide the type of; clarify into a type
(tr) med to determine the blood group of (a blood sample)
(tr) mainly Christian theol to foreshadow or serve as a symbol of (some future reality)
SEE MORESEE LESS - Word Origin for type
Word Origin for type - C15: from Latin typus figure, from Greek tupos image, from tuptein to strike
C15: from Latin typus figure, from Greek tupos image, from tuptein to strike
Medical definitions for type - type
type - [ tp ]
[ tp ] - n.
n. - A number of people or things having in common traits or characteristics that distinguish them as a group or class.
A number of people or things having in common traits or characteristics that distinguish them as a group or class.
The general character or structure held in common by a number of people or things considered as a group or class.
A person or thing having the features of a group or class.
An example or a model having the ideal features of a group or class.
A taxonomic group, especially a genus or species, chosen as the representative example in characterizing the larger taxonomic group to which it belongs.
The specimen on which the original description and naming of a taxon is based.
SEE MORESEE LESS - v.
v. - To determine the antigenic characteristics of a blood or tissue sample.
To determine the antigenic characteristics of a blood or tissue sample.
Key: "S:" = Show Synset (semantic) relations, "W:" = Show Word (lexical) relations
Display options for sense: (gloss) "an example sentence"
Noun - S: (n) projection (a prediction made by extrapolating from past observations)
S: (n) projection (a prediction made by extrapolating from past observations)
S: (n) projection (the projection of an image from a film onto a screen)
S: (n) projection (any structure that branches out from a central support)
S: (n) projection (any solid convex shape that juts out from something)
S: (n) projection ((psychiatry) a defense mechanism by which your own traits and emotions are attributed to someone else)
S: (n) projection, acoustic projection, sound projection (the acoustic phenomenon that gives sound a penetrating quality) "our ukuleles have been designed to have superior sound and projection"; "a prime ingredient of public speaking is projection of the voice"
S: (n) projection (the representation of a figure or solid on a plane as it would look from a particular direction)
What Are Building Operations? - Definition
Definition - Building operations consists of the activities necessary to operate, maintain, and manage buildings. This includes maintaining the HVAC systems, plumbing, electrical, and building system configuration.
Building operations consists of the activities necessary to operate, maintain, and manage buildings. This includes maintaining the HVAC systems, plumbing, electrical, and building system configuration.
Why its Important - Because building operations cover so many areas, many real estate companies have separate departments for operations, utilities, sustainability, and engineering. Here are the most important areas to address in building operations:
Because building operations cover so many areas, many real estate companies have separate departments for operations, utilities, sustainability, and engineering. Here are the most important areas to address in building operations:
Maintenance Techniques - Maintenance strategy and control, transitioning from reactive to proactive maintenance, maintenance contracts, establishing a minimum standard for inspection and maintenance of equipment, operating and maintenance documentation, and maintenance technician training.
Owning and Operating Costs - First costs of building ownership, new building construction project delivery methods, estimating costs, service life, depreciation, recurring cost, maintenance costs, utility costs, regulatory costs, utility billing analysis, and economic analysis
Heating, Ventilating, and Air-Conditioning Controls - Control components, specifying control systems and writing control sequences, effective use of control technology, using the control system for energy management, impact of controls of operating costs, emerging control technologies and strategies.
Contractor Start-Up and Handover Procedures - Pre-start-up procedures, equipment and system start-up and testing, operator training, substantial completion and occupancy permit, handover procedures, record drawings, operating and maintenance documents, warranty, and post warranty operation.
Commissioning and Testing - Commissioning process and benefits; functional acceptance testing; testing, adjusting, and balancing (TAB); and existing building commissioning
Risk Assessment Procedures - Defining risk, emergency response plans, activating an emergency response plan, types of risk and what to do during an emergency, and what to do after an emergency.
Greening Your Facility - Utilizing a building monitoring system to understand the energy costs related to each piece of equipment in real time. In addition, tenant submetering helps ensure that tenants are incentivized to reduce costs.
Health and Safety - Health and safety regulations and policies, organizational health and safety programs, safe work practices, and building operating regulations.
What is Asset Identification? Methods of Asset Identification, Best Practices, and More
Asset identification is an important process for organizations that manage a variety of fixed or movable assets, and its an essential component of an overall asset tracking system. Heres a look at the methods of asset identification, best practices, and more.
A Definition of Asset Identification - Asset identification is a critical process for any business because knowing which equipment you have is essential to being able to track it. If your assets are labeled incorrectly, or if you have duplicate labels, you risk facing compliance issues, falling behind with preventive maintenance, and putting your assets at risk of being stolen or lost. Utilizing asset identification best practices with fixed and movable physical assets is the foundation of efficient asset tracking for your business.
Asset identification is a critical process for any business because knowing which equipment you have is essential to being able to track it. If your assets are labeled incorrectly, or if you have duplicate labels, you risk facing compliance issues, falling behind with preventive maintenance, and putting your assets at risk of being stolen or lost. Utilizing asset identification best practices with fixed and movable physical assets is the foundation of efficient asset tracking for your business.
Methods of Asset Identification - The most common method of asset identification is asset tags. Also known as asset labels, asset tags can be used to identify a range of physical assets, including equipment, tools, racks, and machines. These asset tags include serial numbers that serve as unique identification numbers. Asset tags may be made of foil, aluminum, premium polyester, or vinyl. You can use barcode label asset tags to identify your assets. Barcodes also are assigned a unique identification number, which can be scanned into an asset tracking software solution with handheld scanners or mobile devices. All of the asset data is contained within the program, empowering users to locate a specific asset quickly and easily. Some programs also include maintenance schedules, warranty information, and maintenance history for assets. Radio Frequency Identification (RFID) asset tags also are an option for asset identification. Unlike barcode tags, RFID tags do not have to be directly in the line of sight of scanners to be detected because RFID readers send out radio waves detected by the antenna within the tag. One disadvantage of RFID asset tags is their cost. Not only do RFID labels cost more than barcode labels, but RFID readers are more expensive than barcode scanners.
The most common method of asset identification is asset tags. Also known as asset labels, asset tags can be used to identify a range of physical assets, including equipment, tools, racks, and machines. These asset tags include serial numbers that serve as unique identification numbers. Asset tags may be made of foil, aluminum, premium polyester, or vinyl. You can use barcode label asset tags to identify your assets. Barcodes also are assigned a unique identification number, which can be scanned into an asset tracking software solution with handheld scanners or mobile devices. All of the asset data is contained within the program, empowering users to locate a specific asset quickly and easily. Some programs also include maintenance schedules, warranty information, and maintenance history for assets. Radio Frequency Identification (RFID) asset tags also are an option for asset identification. Unlike barcode tags, RFID tags do not have to be directly in the line of sight of scanners to be detected because RFID readers send out radio waves detected by the antenna within the tag. One disadvantage of RFID asset tags is their cost. Not only do RFID labels cost more than barcode labels, but RFID readers are more expensive than barcode scanners.
Asset Identification Best Practices - To maximize your fixed asset identification efforts, implement best practices across your organization. To be cost-effective, prioritize identifying high-value assets including those that depreciate. You also should identify moveable assets and those requiring regular maintenance, repairs, or replacement parts like equipment and machinery. Thus, you should label IT hardware like computers and servers, audio-visual equipment like projectors, fixed assets, critical equipment like machines and tools, and furniture like desks and filing cabinets. Another asset identification best practice is implementing an asset tracking solution. No matter which type of asset identification your company chooses to use, you will benefit from eliminating manual data entry that can be rife with error. Scanning automates processes and makes asset identification and tracking much more reliable and efficient. Benefits of Asset Identification Proper asset identification methods give your company full visibility into your assets when paired with an asset tracking solution. You will know where your assets are located, even if they are used outside your business. You also will have records of asset usage and movement. With asset tags and an asset tracking solution, companies can note the condition of fixed assets to assist in scheduling maintenance, making purchases at appropriate times, and determining the value of your business more accurately. Identifying and tracking your assets also makes it easier to report their depreciation. It makes more financial sense for you to depreciate the expense of fixed assets to account for their declining value than to report the entire cost of the asset in one year. When you track each fixed assets depreciation status, you file more accurate business tax returns.
To maximize your fixed asset identification efforts, implement best practices across your organization. To be cost-effective, prioritize identifying high-value assets including those that depreciate. You also should identify moveable assets and those requiring regular maintenance, repairs, or replacement parts like equipment and machinery. Thus, you should label IT hardware like computers and servers, audio-visual equipment like projectors, fixed assets, critical equipment like machines and tools, and furniture like desks and filing cabinets. Another asset identification best practice is implementing an asset tracking solution. No matter which type of asset identification your company chooses to use, you will benefit from eliminating manual data entry that can be rife with error. Scanning automates processes and makes asset identification and tracking much more reliable and efficient. Benefits of Asset Identification Proper asset identification methods give your company full visibility into your assets when paired with an asset tracking solution. You will know where your assets are located, even if they are used outside your business. You also will have records of asset usage and movement. With asset tags and an asset tracking solution, companies can note the condition of fixed assets to assist in scheduling maintenance, making purchases at appropriate times, and determining the value of your business more accurately. Identifying and tracking your assets also makes it easier to report their depreciation. It makes more financial sense for you to depreciate the expense of fixed assets to account for their declining value than to report the entire cost of the asset in one year. When you track each fixed assets depreciation status, you file more accurate business tax returns.
A Final Word on Asset Identification - Asset identification is your first line of defense against stolen and lost assets. It also is the foundation of asset management and tracking efforts. Thats why it is so important for you to choose the right durable labels for your assets, from Foil Asset Labels for metal, plastic, textured, and contoured surfaces, to Rigid Metalphoto Aluminum Asset Tags that can withstand harsh environments. Image via Pixabay by PDPhotos and Flickr by tnarik
Asset identification is your first line of defense against stolen and lost assets. It also is the foundation of asset management and tracking efforts. Thats why it is so important for you to choose the right durable labels for your assets, from Foil Asset Labels for metal, plastic, textured, and contoured surfaces, to Rigid Metalphoto Aluminum Asset Tags that can withstand harsh environments. Image via Pixabay by PDPhotos and Flickr by tnarik
Recommended Reading on Asset Identification - For more information on asset identification, visit the following articles:
For more information on asset identification, visit the following articles:
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Contact Us - Camcode Division of Horizons Incorporated 18531 South Miles Road Cleveland, Ohio 44128
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(sports) The use of all the width of the pitch, from one side to the other.
Manchester United like to play with width. - noun
noun - 1
1 - 0
0 - A piece of material measured along its smaller dimension or its crosswise grain, especially a piece of fabric measured from selvage to selvage.
A piece of material measured along its smaller dimension or its crosswise grain, especially a piece of fabric measured from selvage to selvage.
noun - 1
1 - 1
1 - Advertisement
Advertisement - Width is defined as the quality of being wide, or the measurement of distance from side to side.
Width is defined as the quality of being wide, or the measurement of distance from side to side.
An example of width is a 36" measurement for a table's wideness.
Origin of width - From American Heritage Dictionary of the English Language, 5th Edition
From American Heritage Dictionary of the English Language, 5th Edition
From Wiktionary - Width Sentence Examples
Width Sentence Examples - wide, the Bafing at this point having a width of 360 ft.
wide, the Bafing at this point having a width of 360 ft.
Geologically considered, the country may be divided into three regions - a central, and the largest, comprising the whole width of the Aravalli system, formed of very old sub-metamorphic and gneissic rocks; an eastern region, with sharply defined boundary, along which the most ancient formations are abruptly replaced by the great basin of the Vindhyan strata, or are overlaid by the still more extensive spread of the Deccan trap, forming the plateau of Malwa; and a western region, of very ill-defined margin, in which, besides some rocks of undetermined age, it is more or less known or suspected that Tertiary and Secondary strata stretch across from Sind, beneath the sands of the desert, towards the flanks of the Aravallis.
He had not ridden many hundred yards after that before he saw to his left, across the whole width of the field, an enormous mass of cavalry in brilliant white uniforms, mounted on black horses, trotting straight toward him and across his path.
in width and from 3 to 5 fathoms deep, navigable for steamers of good size.
The two trees whose girth had been small enough for her wrap her arms around had expanded in width and height, reaching towards the gray sky of the underworld. Katie craned her neck, unable to see the tops of the trees. Their trunks had grown outward from the trail until they were as wide as a football field. Their massive roots ruptured the ground that had been the trail, creating a ravine she could see even from their safe distance.
Oxford English and Spanish Dictionary, Synonyms, and Spanish to English Translator
Definition of with in English: - with
with - Pronunciation /wiTH/ /w/ /wiTH/ /w/
Pronunciation /wiTH/ /w/ /wiTH/ /w/
preposition - 1Accompanied by (another person or thing)
1Accompanied by (another person or thing) - a nice steak with a bottle of red wine
a nice steak with a bottle of red wine
More example sentences - It is accompanied with a golden vest and hair ornament hanging down to the shoulder.
It is accompanied with a golden vest and hair ornament hanging down to the shoulder.
The tamarind provides a novel change to lemon as an accompaniment with the prawn.
Stumped for a good red wine capable of accompanying duck served with a bitter cherry sauce?
She grew up in a small house in Brixton, sharing a bedroom with three brothers.
It takes me right back to the bedroom I shared with my brothers back in the early seventies.
The same could not be said of my fillet steak with a Stilton and red wine sauce.
And when it got dark he came in and played hurling games in the bedroom with his brothers.
She picked up her make up bag and left the wash room, heading to the bedroom she shared with her best friend.
Lunch would be stew or steak and kidney pud with potatoes and boiled green vegetables.
The truffle taste was strong and earthy and worked in nice harmony with the risotto.
I need a nice early night with my boy and hopefully a tiny bit of a lie in!
Apparently, we are going to be able to put plastic in with our cans and bottles.
I went for a nice meal with my parents yesterday before having to catch the train home.
It allows me to have a bit of a flirt and a bit of a laugh with some very nice girls.
He thought I was going to force him to sit in a corner and drink a bottle of wine with me.
John is just a lovely man and the rest of the cast, I mean you couldn't ask to work with nicer people.
She hooked up with a nice couple in England, and now they exchange occasional letters.
Contents insurance can be bought separately, with building cover or in a joint policy.
She trained at the Royal Ballet School and performed briefly with the Royal Ballet.
Place the polenta, flour and baking powder in a bowl with the salt and sugar.
the form of the light curve changes with period in a systematic way
2Possessing (something) as a feature or accompaniment.
a flower-sprigged blouse with a white collar - More example sentences
More example sentences - The Firth of Tay glittered like crumpled silver foil, and the city shone with an inner light.
The Firth of Tay glittered like crumpled silver foil, and the city shone with an inner light.
The house was fitted with a smoke alarm at the top of the stairs but the battery had run out.
He was wearing dark trousers and a white shirt with a collar, which he wore unbuttoned.
Her eyes were alight, her hair flaxen, her golden skin shining with more than just the glow of youth.
He wore a black beanie hat with a white stripe, jeans, and a black, padded, hooded jacket.
When she vanished Sammy was wearing navy tracksuit bottoms with a white stripe down both legs.
The modern bathroom is fitted with a white three-piece suite including a corner bath.
He appeared drunk and was wearing a white sweatshirt with blue writing in the centre.
After all, people with money and status employ other people to clean up after them.
In fact it does not permit entry to people with relatively minor criminal records.
He is also a keen violinist, with vast experience performing in various countries.
The lake is an official recreation area with all sorts of water activities plus hiking and camping.
Its website is really nice, with lots of old articles and a complete cover gallery.
Upstairs is the huge master bedroom with a pitched-pine floor and vaulted ceilings.
On the first floor are four large doubles bedrooms with en suites as well as a single room.
The pint-sized bottles with the green labels were called screw tops and were a powerful icon to me.
At least if I play things right I can slip out at the end into a nice public sector job with a pension.
He is still best known as a financier with a reputation that carries weight in the City and beyond.
It was narrow but tall, with dark red curtains hanging at each side and trailing on the floor.
I'm not one of those that laments the old thick dimpled beer tankards with handles on the side.
2.1Marked by or wearing. - a small man with thick glasses
a small man with thick glasses - More example sentences
More example sentences - a tall dark man with a scar on one cheek
a tall dark man with a scar on one cheek
He was a slight man wearing owl glasses, with thin brown hair that left a bald spot on the back of his head.
Thinly built, with thick glasses and K-Mart clothes, Lee is as cheery as he is modest.
She was a bit taller than Dai with short thick curly hair and tanned skin, much like his own.
She is also five feet five inches tall with a scar under her nose and brown hair.
On a bad-takings day, he'd show up with dark glasses and a white stick and blow his harmonica.
After a short wait, a tall man with cropped dark hair and warm green eyes opened the door.
He was wearing dark blue jeans, with a dark blue hooded jacket and a blue plastic coat.
Will I get in trouble for trawling the streets of Torquay with a can of Stella in my hand?
He accompanies me back, with some tools, which prove not to be any help whatsoever.
Mr Massow was on television this morning again, with his rather alarming new haircut.
The woman is described as white, young, with brown hair and is believed to be called Debbie.
The victim is white and stocky, with brown eyes, a square jaw and a pointed nose.
Joanne is described as white, with light blonde hair worn just below her shoulders.
The man with the white beard rose to his feet and strode over to the baby weeping on the ground.
3Indicating the instrument used to perform an action.
cut it with a knife - More example sentences
More example sentences - treatment with acid before analysis
treatment with acid before analysis - He had a seat belt on and we cut it with a knife and tried to pull him out but we couldn't.
He had a seat belt on and we cut it with a knife and tried to pull him out but we couldn't.
They set to work on the oxhide with the knives and cut it into a single thin strip.
Quarter the apples, then peel and cut away the core with a small paring knife.
One of them steps forward and with his knife cuts the burden free and it falls to the bottom of the ravine.
It need not be so thick you could cut it with a knife, but it should be well on the way.
The proposal would also make it an offence to hit a child with an instrument, such as a belt or a cane.
She had been struck three times across the back of the head with a blunt instrument, believed to be a hammer.
My throat felt rather like it had been scraped with a sharp metal instrument.
He believes the problem started when someone armed with a Stanley knife took to cutting tyres.
The lever couldn't be removed without undoing the nut so I decided to cut it with my hacksaw.
When I cut through it with my saw, the centre was rotten, so it's just as well it was coming out.
Cut off the top of the heads with a serrated knife and squeeze out the garlic pulp.
She cuts the potato into chip shapes with a knife, puts them in a pan full of cold oil and turns on the gas.
Swimming and fishing with home-made rods was still very popular when he was growing up.
All I achieved was to bang a hole in my bedroom wall with the heel of my foot.
A motorist who stopped in a lay-by was hit over the head with a bottle and robbed.
He attacked him with a bottle in the town centre after asking him for money.
I grabbed the knife to try and stop him, but somebody behind me hit me on the head with a bottle.
Anything with a crust, between two slices of bread or poured into a bowl and eaten with a spoon is allowed.
Dissolve the glucose and water together, and with an electric whisk add this to the egg mix.
3.1Indicating the material used for some purpose.
fill the bowl with water - More example sentences
More example sentences - On the table was a vase of plastic wildflowers in a vase partly filled with plastic water.
On the table was a vase of plastic wildflowers in a vase partly filled with plastic water.
The tin bath was hung on a nail on the back yard wall, was brought indoors on bath days, filled with hot water.
We filled it with water and added blue dye, so that if it leaked then we could tell easily.
Is it me, or is it also missing the fact that you'll need to get up to fill the kettle with water in the first place?
Using a slotted spoon, fill the lined bowl with the fruit to about a centimetre below the top.
Usually the barrel is merely rinsed or filled with cold water to check for leaks.
Fill your bath with hot water, and add a generous amount of bath oil or gel for that touch of luxury.
Shake a few gravy granules, or break a stock cube over the top and fill the dish with water.
She took the kettle out of its cradle and filled it with water before setting it to boil.
She watched him as he grabbed a glass from the draining board and filled it with water.
He returned a few moments later with white clothes and a mug filled with sweet water.
Place the salad in a bowl and top with the tomatoes, feta and warm aubergine.
Moisten the edges of the pastry with water and then wrap it around the meat, pressing the joins well to seal.
I'd also suggest you eat porridge in the morning, making it with water instead of milk.
I have a memory of being splattered with holy water but I might have made that up.
Put the potatoes into a saucepan, cover with cold water, add salt and cook until tender.
He said it took the two crews ten minutes to fight the fire with foam and ten minutes to damp the car down with water.
Brush the pastry with egg and cut two holes in the top to let the steam out.
Rub the monk fish tail with the garlic and dill and lay it an oven-proof dish.
Cover with a cut piece of greased paper and then wrap well in several layers of protective foil.
4In opposition to. - we started fighting with each other
we started fighting with each other - More example sentences
More example sentences - So much information has come up since my fight with Shirley and none of it is good.
So much information has come up since my fight with Shirley and none of it is good.
Teachers learned about the incident when Kyle was spotted fighting with the boy.
He shows a teenage mother fighting with the father of her child about his failings as a parent.
He even claimed to have fought with him in the hills and he threatened to show us his wound.
Edwards' next major contribution was to have a fight with Patel which earned both a yellow card.
She has a fight with Queenie in a ladies loo, which gets seriously out of hand.
You go to him and tell him that Ramacandra does not have any intention to fight with him.
Fights with the riot police erupted every time people tried to reach the US embassy.
James goes off to fight with the Pretender, and is reported to have been killed at Culloden.
I told her about the fight Kip had with Nathanial, and she and Rio were as shocked as I was.
One night, after a fight with the man, she took an unknown dose of sleeping pills.
To do this meant a fight with the old London County Council and the government about money.
He became involved in a fight with some other children and his left elbow was dislocated.
Three years ago he was convicted of actual bodily harm, after a fight with a neighbour.
A guy who was part of the sanitation police was there and he started fighting with them.
It was easy to fight with Livi sometimes, but it was also hard trying to stay mad at her for very long.
He only fought with real men who deserved it, not little boys who taunted and teased.
There is no way that they want to enter a fight with millions of workers this close to an election.
I met one man who had quit his job after a row with his boss and had terrible difficulty finding another.
He was apparently angry after arguing with his girlfriend and took out that anger on the dog.
5Indicating the manner or attitude of the person doing something.
with great reluctance - More example sentences
More example sentences - She came to his studio with attitude, but cradled his face in her hands to kiss him before she left.
She came to his studio with attitude, but cradled his face in her hands to kiss him before she left.
Large checks, iridescent fabrics and decadent velvet are all worn with attitude.
It meant that down the years we would collide always with the same pleasure.
Many of those who voted in favour did so with a reluctance somewhat aside from the military arguments.
It is a juggling act he accomplished with some aplomb during his first half-season in charge.
The link is the instruments for which they are written, performed with great skill and feeling.
I pulled the chain on the shade of my bedroom window with a certain mournful sense of ceremony.
Every person has a responsibility to behave with integrity, honesty and fairness.
6Indicating responsibility. - leave it with me
leave it with me - More example sentences
More example sentences - The final sentence, however, rests with the judge and Beaney may still be put behind bars.
The final sentence, however, rests with the judge and Beaney may still be put behind bars.
The final decision on that rests with the trade and industry secretary.
In libel the burden of proof rests with the defendant, and there is no entitlement to legal aid.
The hopes for the future of any local community rest largely with its young people.
7In relation to. - my father will be angry with me
my father will be angry with me - More example sentences
More example sentences - Other times, he will say that he is angry with us, and that we have to be sad.
Other times, he will say that he is angry with us, and that we have to be sad.
She was a master of tuning him out when she was angry with him and it drove him nuts.
There are a lot of people in power wanting to make it real easy to be angry with America.
After all, in the other sins God was angry with people who were hurting other people.
Brown was so angry with his players that he could barely bring himself to talk to them.
Two of his children had died and they said it was because the gods were angry with him.
Was she so angry with me that she was ignoring me or did she really not care about what happened?
He tried to get me to stop, obviously, but I just got more and more angry with him.
I am getting very angry with teams bringing it to us and us being slow starters.
I was about to turn and talk to Rachel but remembered that she was angry with me.
She wasn't sure if Jadrien was angry with her or just James, but she didn't want to find out.
She knew it was a childish action but she found that she was not angry with him anymore.
She had tried desperately to be angry with William Ingalls, but all she wanted to do was die.
I felt angry with them for being so upbeat and pretending that nothing had happened.
Don't try this exercise when either of you is feeling angry or hurt with the other.
You were angry with the monks for deciding this, but afraid that this would come true.
They feel betrayed and are as angry with Bush and Blair as those who always opposed the war.
Many people in the Labour Party are angry with Smith because of his support for the war.
Should this change be accepted everyone who is angry with his brother may be judged.
He said that then he tore my drawing up and threw it in the fire because he was angry with me.
7.1Affected by (a particular fact or condition)
with no hope - More example sentences
More example sentences - in bed with lumbago
in bed with lumbago - I've been laid up in bed with a nasty flu the last few days, and time is warping on me.
I've been laid up in bed with a nasty flu the last few days, and time is warping on me.
Blue and yellow are not distinguished by those with this condition, and may be seen as white or grey.
It is the largest clinical trial to be carried out in patients with early ovarian cancer.
A high proportion of women with osteoarthritis of the hip also have low bone density.
7.2Indicating the cause of an action or condition.
trembling with fear - More example sentences
More example sentences - the paper was yellow with age
the paper was yellow with age - She just stood there; the look of terror on her face increased and she began to tremble with the fear.
She just stood there; the look of terror on her face increased and she began to tremble with the fear.
wisdom comes with age - 8Employed by.
8Employed by. - If he'd still been employed with us we would have suspended him immediately, but he was retired.
If he'd still been employed with us we would have suspended him immediately, but he was retired.
8.1As a member or employee of. - he plays with the Cincinnati Cyclones
he plays with the Cincinnati Cyclones - More example sentences
More example sentences - In August, the future started to look brighter after he secured a job with another removal firm.
In August, the future started to look brighter after he secured a job with another removal firm.
I bank with the TSB - 9In the same direction as.
9In the same direction as. - Our boat drifts with the gentle current for an hour or so before gently motoring over to San Toribo reef.
Our boat drifts with the gentle current for an hour or so before gently motoring over to San Toribo reef.
10Indicating separation or removal from something. - to part with one's dearest possessions
to part with one's dearest possessions - More example sentences
More example sentences - their jobs could be dispensed with
their jobs could be dispensed with - The mansions formerly lining the High Street were replaced with retail premises.
The mansions formerly lining the High Street were replaced with retail premises.
Phrases - be with someone
be with someone - 1Agree with or support someone.
1Agree with or support someone. - we're all with you on this one
we're all with you on this one - More example sentences
More example sentences - The president stated emphatically that though he had asked Powell to be with him and support him in a war, I didn't need his permission.
The president stated emphatically that though he had asked Powell to be with him and support him in a war, I didn't need his permission.
In a state like Iowa, the winner is probably only going to have 30, 35 percent of the vote, which means about two-thirds of Tom Harkin supporters are going to be with somebody else.
For those of you who've been with me from the beginning, thanks for the support and so long.
It was during times like these that he missed having Julie by his side; she would support him in this career change and she would've been with him in success and in failure.
Paul Flannery said he was especially happy at the support of Bank of Ireland who had been with him all the way.
At the close of the season it is timely to thank our sponsors and supporters, many of whom have been with us since Norpa's inception in 1993.
We knew that there were people against it but we thought most were with us.
Either you were with us or you weren't.
2informal Follow someone's meaning. - More example sentences
More example sentences - I'm not with you
I'm not with you - While we may think the prospect is with us, or understands what we are explaining, it is often difficult for the listener to grasp the logic of our argument.
While we may think the prospect is with us, or understands what we are explaining, it is often difficult for the listener to grasp the logic of our argument.
with that - At that point; immediately after saying or doing something dramatic.
At that point; immediately after saying or doing something dramatic.
More example sentences - with that, she flounced out of the room
with that, she flounced out of the room
Used in exhortations to take or send someone or something away, in, out, etc.
off with his head - More example sentences
More example sentences - away with poverty!
away with poverty! - Origin
Origin - Old English, probably a shortening of a Germanic preposition related to obsolete English wither adverse, opposite.
Old English, probably a shortening of a Germanic preposition related to obsolete English wither adverse, opposite.
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Rail height - The height of the top-most rail in the railing structure.
The height of the top-most rail in the railing structure.
Rail Structure - Opens a separate dialog where you set the number of rails, height, offset, material, and profile family (shape) for each rail. See Modifying the Railing Structure.
Opens a separate dialog where you set the number of rails, height, offset, material, and profile family (shape) for each rail. See Modifying the Railing Structure.
Baluster Offset - Offsets the balusters from the rail sketch line. By setting a value for this property and rail offsets, you can create different combinations of rails and balusters.
Offsets the balusters from the rail sketch line. By setting a value for this property and rail offsets, you can create different combinations of rails and balusters.
Use Landing Height Adjustment - This parameter controls the height of railings at landings. If set to No, railings at landings use the same height as they do over stair runs. If set to Yes, the railing height is adjusted up or down by the amount set for Landing Height Adjustment. To get smooth railing connections, set the Tangent Joins parameter to Extend Rails to Meet.
This parameter controls the height of railings at landings. If set to No, railings at landings use the same height as they do over stair runs. If set to Yes, the railing height is adjusted up or down by the amount set for Landing Height Adjustment. To get smooth railing connections, set the Tangent Joins parameter to Extend Rails to Meet.
Landing Height Adjustment - Raises or lowers the height of the railing from the value indicated in the Railing Height parameter at intermediate or top landings.
Raises or lowers the height of the railing from the value indicated in the Railing Height parameter at intermediate or top landings.
Angled Joins - If 2 railing segments meet at an angle in plan but do not connect vertically, Revit Architecture can add vertical or horizontal segments to create a join or add no connector, leaving a gap. This can be used to create a continuous railing where the start of a stair run leading up from a landing cannot be displaced by one tread width. Join methods can be overridden on an connection-by-connection basis. See Modifying Railing Joins.
If 2 railing segments meet at an angle in plan but do not connect vertically, Revit Architecture can add vertical or horizontal segments to create a join or add no connector, leaving a gap. This can be used to create a continuous railing where the start of a stair run leading up from a landing cannot be displaced by one tread width. Join methods can be overridden on an connection-by-connection basis. See Modifying Railing Joins.
Tangent Joins - If 2 tangent railing segments are collinear or tangent in plan but do not connect vertically, Revit Architecture can add vertical or horizontal segments to create a join, extend segments to meet, or add no connector leaving a gap. This can be used to create a smooth junction when the railing height is modified at a landing or the railing turns out at the bottom of a stair. Join methods can be overridden on a connection-by-connection basis. See Modifying Railing Joins.
If 2 tangent railing segments are collinear or tangent in plan but do not connect vertically, Revit Architecture can add vertical or horizontal segments to create a join, extend segments to meet, or add no connector leaving a gap. This can be used to create a smooth junction when the railing height is modified at a landing or the railing turns out at the bottom of a stair. Join methods can be overridden on a connection-by-connection basis. See Modifying Railing Joins.
Rail Connections - When connections are made between railing segments, Revit Architecture tries to create mitered joins. If it cannot make a mitered join, then segments can be trimmed, which means they are cut with a vertical plane, or they can be welded, which means they are joined in a manner as close to a miter as possible. Welded connections work best for circular rail profiles.
When connections are made between railing segments, Revit Architecture tries to create mitered joins. If it cannot make a mitered join, then segments can be trimmed, which means they are cut with a vertical plane, or they can be welded, which means they are joined in a manner as close to a miter as possible. Welded connections work best for circular rail profiles.
Identity Data - Keynote
Keynote - Add or edit the railing keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
Add or edit the railing keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars; see below. For the Gregorian calendar, the average length of the calendar year (the mean year) across the complete leap cycle of 400 years is 365.2425 days. The ISO standard ISO 80000-3, Annex C, supports the symbol a (for Latin annus) to represent a year of either 365 or 366 days.[failed verification] In English, the abbreviations y and yr are commonly used.
The word year is also used for periods loosely associated with, but not identical to, the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Similarly, year can mean the orbital period of any planet; for example, a Martian year and a Venusian year are examples of the time a planet takes to transit one complete orbit. The term can also be used in reference to any long period or cycle, such as the Great Year.[2]
Latin annus (a 2nd declension masculine noun; annum is the accusative singular; ann is genitive singular and nominative plural; ann the dative and ablative singular) is from a PIE noun *het-no-, which also yielded Gothic an "year" (only the dative plural anam is attested).
Although most languages treat the word as thematic *yehr-o-, there is evidence for an original derivation with an *-r/n suffix, *yeh-ro-. Both Indo-European words for year, *yeh-ro- and *het-no-, would then be derived from verbal roots meaning "to go, move", *hey- and *het-, respectively (compare Vedic Sanskrit ti "goes", atasi "thou goest, wanderest"). A number of English words are derived from Latin annus, such as annual, annuity, anniversary, etc.; per annum means "each year", ann Domin means "in the year of the Lord".
The Greek word for "year", , is cognate with Latin vetus "old", from the PIE word *wetos- "year", also preserved in this meaning in Sanskrit vat-sa-ras "year" and vat-sa- "yearling (calf)", the latter also reflected in Latin vitulus "bull calf", English wether "ram" (Old English weer, Gothic wirus "lamb").
In some languages, it is common to count years by referencing to one season, as in "summers", or "winters", or "harvests". Examples include Chinese "year", originally , an ideographic compound of a person carrying a bundle of wheat denoting "harvest". Slavic besides god "time period; year" uses lto "summer; year".
Intercalation - Astronomical years do not have an integer number of days or lunar months. Any calendar that follows an astronomical year must have a system of intercalation such as leap years.
Astronomical years do not have an integer number of days or lunar months. Any calendar that follows an astronomical year must have a system of intercalation such as leap years.
Julian calendar - In the Julian calendar, the average (mean) length of a year is 365.25 days. In a non-leap year, there are 365 days, in a leap year there are 366 days. A leap year occurs every fourth year, or leap year, during which a leap day is intercalated into the month of February. The name "Leap Day" is applied to the added day.
In the Julian calendar, the average (mean) length of a year is 365.25 days. In a non-leap year, there are 365 days, in a leap year there are 366 days. A leap year occurs every fourth year, or leap year, during which a leap day is intercalated into the month of February. The name "Leap Day" is applied to the added day.
The Revised Julian calendar, proposed in 1923 and used in some Eastern Orthodox Churches, has 218 leap years every 900 years, for the average (mean) year length of 365.2422222 days, close to the length of the mean tropical year, 365.24219 days (relative error of 9108). In the year 2800 CE, the Gregorian and Revised Julian calendars will begin to differ by one calendar day.[3]
Gregorian calendar - The Gregorian calendar attempts to cause the northward equinox to fall on or shortly before March 21 and hence it follows the northward equinox year, or tropical year.[4] Because 97 out of 400 years are leap years, the mean length of the Gregorian calendar year is 365.2425 days; with a relative error below one ppm (8107) relative to the current length of the mean tropical year (365.24219 days) and even closer to the current March equinox year of 365.242374 days that it aims to match. It is estimated that by the year 4000 CE, the northward equinox will fall back by one day in the Gregorian calendar, not because of this difference, but due to the slowing of the Earth's rotation and the associated lengthening of the day.
The Gregorian calendar attempts to cause the northward equinox to fall on or shortly before March 21 and hence it follows the northward equinox year, or tropical year.[4] Because 97 out of 400 years are leap years, the mean length of the Gregorian calendar year is 365.2425 days; with a relative error below one ppm (8107) relative to the current length of the mean tropical year (365.24219 days) and even closer to the current March equinox year of 365.242374 days that it aims to match. It is estimated that by the year 4000 CE, the northward equinox will fall back by one day in the Gregorian calendar, not because of this difference, but due to the slowing of the Earth's rotation and the associated lengthening of the day.
Other calendars - Historically, lunisolar calendars intercalated entire leap months on an observational basis. Lunisolar calendars have mostly fallen out of use except for liturgical reasons (Hebrew calendar, various Hindu calendars).
Historically, lunisolar calendars intercalated entire leap months on an observational basis. Lunisolar calendars have mostly fallen out of use except for liturgical reasons (Hebrew calendar, various Hindu calendars).
A modern adaptation of the historical Jalali calendar, known as the Solar Hijri calendar (1925), is a purely solar calendar with an irregular pattern of leap days based on observation (or astronomical computation), aiming to place new year (Nowruz) on the day of vernal equinox (for the time zone of Tehran), as opposed to using an algorithmic system of leap years.
Year numbering - A calendar era assigns a cardinal number to each sequential year, using a reference point in the past as the beginning of the era.
A calendar era assigns a cardinal number to each sequential year, using a reference point in the past as the beginning of the era.
The worldwide standard is the Anno Domini, although some prefer the term Common Era because it has no explicit reference to Christianity. It was introduced in the 6th century and was intended to count years from the nativity of Jesus.[5]
The Anno Domini era is given the Latin abbreviation AD (for Anno Domini "in the year of the Lord"), or alternatively CE for "Common Era". Years before AD 1 are abbreviated BC for Before Christ or alternatively BCE for Before the Common Era. Year numbers are based on inclusive counting, so that there is no "year zero". In the modern alternative reckoning of Astronomical year numbering, positive numbers indicate years AD, the number 0 designates 1 BC, 1 designates 2 BC, and so on.
Pragmatic divisions - Financial and scientific calculations often use a 365-day calendar to simplify daily rates.
Financial and scientific calculations often use a 365-day calendar to simplify daily rates.
Fiscal year - A fiscal year or financial year is a 12-month period used for calculating annual financial statements in businesses and other organizations. In many jurisdictions, regulations regarding accounting require such reports once per twelve months, but do not require that the twelve months constitute a calendar year.
A fiscal year or financial year is a 12-month period used for calculating annual financial statements in businesses and other organizations. In many jurisdictions, regulations regarding accounting require such reports once per twelve months, but do not require that the twelve months constitute a calendar year.
For example, in Canada and India the fiscal year runs from April 1; in the United Kingdom it runs from April 1 for purposes of corporation tax and government financial statements, but from April 6 for purposes of personal taxation and payment of state benefits; in Australia it runs from July 1; while in the United States the fiscal year of the federal government runs from October 1.
Academic year - An academic year is the annual period during which a student attends an educational institution. The academic year may be divided into academic terms, such as semesters or quarters. The school year in many countries starts in August or September and ends in May, June or July. In Israel the academic year begins around October or November, aligned with the second month of the Hebrew calendar.
An academic year is the annual period during which a student attends an educational institution. The academic year may be divided into academic terms, such as semesters or quarters. The school year in many countries starts in August or September and ends in May, June or July. In Israel the academic year begins around October or November, aligned with the second month of the Hebrew calendar.
Some schools in the UK, Canada and the United States divide the academic year into three roughly equal-length terms (called trimesters or quarters in the United States), roughly coinciding with autumn, winter, and spring. At some, a shortened summer session, sometimes considered part of the regular academic year, is attended by students on a voluntary or elective basis. Other schools break the year into two main semesters, a first (typically August through December) and a second semester (January through May). Each of these main semesters may be split in half by mid-term exams, and each of the halves is referred to as a quarter (or term in some countries). There may also be a voluntary summer session and/or a short January session.
Some other schools, including some in the United States, have four marking periods. Some schools in the United States, notably Boston Latin School, may divide the year into five or more marking periods. Some state in defense of this that there is perhaps a positive correlation between report frequency and academic achievement.
There are typically 180 days of teaching each year in schools in the US, excluding weekends and breaks, while there are 190 days for pupils in state schools in Canada, New Zealand and the United Kingdom, and 200 for pupils in Australia.
In India the academic year normally starts from June 1 and ends on May 31. Though schools start closing from mid-March, the actual academic closure is on May 31 and in Nepal it starts from July 15.[citation needed]
Schools and universities in Australia typically have academic years that roughly align with the calendar year (i.e., starting in February or March and ending in October to December), as the southern hemisphere experiences summer from December to February.
Astronomical years - Julian year
Julian year - The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" used in various scientific contexts. The Julian century of 36525 days and the Julian millennium of 365250 days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive. By convention, the Julian year is used in the computation of the distance covered by a light-year.
The Julian year, as used in astronomy and other sciences, is a time unit defined as exactly 365.25 days. This is the normal meaning of the unit "year" used in various scientific contexts. The Julian century of 36525 days and the Julian millennium of 365250 days are used in astronomical calculations. Fundamentally, expressing a time interval in Julian years is a way to precisely specify how many days (not how many "real" years), for long time intervals where stating the number of days would be unwieldy and unintuitive. By convention, the Julian year is used in the computation of the distance covered by a light-year.
Sidereal, tropical, and anomalistic years - Each of these three years can be loosely called an astronomical year.
Each of these three years can be loosely called an astronomical year.
The sidereal year is the time taken for the Earth to complete one revolution of its orbit, as measured against a fixed frame of reference (such as the fixed stars, Latin sidera, singular sidus). Its average duration is 365.256363004 days (365 d 6 h 9 min 9.76 s) (at the epoch J2000.0 = January 1, 2000, 12:00:00 TT).[6]
Today the mean tropical year is defined as the period of time for the mean ecliptic longitude of the Sun to increase by 360 degrees.[7] Since the Sun's ecliptic longitude is measured with respect to the equinox,[8] the tropical year comprises a complete cycle of the seasons; because of the biological and socio-economic importance of the seasons, the tropical year is the basis of most calendars. The modern definition of mean tropical year differs from the actual time between passages of, e.g., the northward equinox for several reasons explained below. Because of the Earth's axial precession, this year is about 20 minutes shorter than the sidereal year. The mean tropical year is approximately 365 days, 5 hours, 48 minutes, 45 seconds, using the modern definition[9] ( = 365.24219 d 86 400 s).
The anomalistic year is the time taken for the Earth to complete one revolution with respect to its apsides. The orbit of the Earth is elliptical; the extreme points, called apsides, are the perihelion, where the Earth is closest to the Sun (January 5, 07:48 UT in 2020), and the aphelion, where the Earth is farthest from the Sun (July 4, 11:35 UT in 2020). The anomalistic year is usually defined as the time between perihelion passages. Its average duration is 365.259636 days (365 d 6 h 13 min 52.6 s) (at the epoch J2011.0).[10]
Draconic year - The draconic year, draconitic year, eclipse year, or ecliptic year is the time taken for the Sun (as seen from the Earth) to complete one revolution with respect to the same lunar node (a point where the Moon's orbit intersects the ecliptic). The year is associated with eclipses: these occur only when both the Sun and the Moon are near these nodes; so eclipses occur within about a month of every half eclipse year. Hence there are two eclipse seasons every eclipse year. The average duration of the eclipse year is
The draconic year, draconitic year, eclipse year, or ecliptic year is the time taken for the Sun (as seen from the Earth) to complete one revolution with respect to the same lunar node (a point where the Moon's orbit intersects the ecliptic). The year is associated with eclipses: these occur only when both the Sun and the Moon are near these nodes; so eclipses occur within about a month of every half eclipse year. Hence there are two eclipse seasons every eclipse year. The average duration of the eclipse year is
346.620075883 days (346 d 14 h 52 min 54 s) (at the epoch J2000.0).
This term is sometimes erroneously used for the draconic or nodal period of lunar precession, that is the period of a complete revolution of the Moon's ascending node around the ecliptic: 18.612815932 Julian years (6798.331019 days; at the epoch J2000.0).
Full moon cycle - The full moon cycle is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the perigee of the Moon's orbit. This period is associated with the apparent size of the full moon, and also with the varying duration of the synodic month. The duration of one full moon cycle is:
The full moon cycle is the time for the Sun (as seen from the Earth) to complete one revolution with respect to the perigee of the Moon's orbit. This period is associated with the apparent size of the full moon, and also with the varying duration of the synodic month. The duration of one full moon cycle is:
411.78443029 days (411 days 18 hours 49 minutes 35 seconds) (at the epoch J2000.0).
Lunar year - The lunar year comprises twelve full cycles of the phases of the Moon, as seen from Earth. It has a duration of approximately 354.37 days. Muslims use this for celebrating their Eids and for marking the start of the fasting month of Ramadan. A Muslim calendar year is based on the lunar cycle. The Jewish calendar is also essentially lunar, except that an intercalary lunar month is added once every two or three years, in order to keep the calendar synchronized with the solar cycle as well. Thus, a lunar year on the Jewish (Hebrew) calendar consists of either twelve or thirteen lunar months.
The lunar year comprises twelve full cycles of the phases of the Moon, as seen from Earth. It has a duration of approximately 354.37 days. Muslims use this for celebrating their Eids and for marking the start of the fasting month of Ramadan. A Muslim calendar year is based on the lunar cycle. The Jewish calendar is also essentially lunar, except that an intercalary lunar month is added once every two or three years, in order to keep the calendar synchronized with the solar cycle as well. Thus, a lunar year on the Jewish (Hebrew) calendar consists of either twelve or thirteen lunar months.
Vague year - The vague year, from annus vagus or wandering year, is an integral approximation to the year equaling 365 days, which wanders in relation to more exact years. Typically the vague year is divided into 12 schematic months of 30 days each plus 5 epagomenal days. The vague year was used in the calendars of Ethiopia, Ancient Egypt, Iran, Armenia and in Mesoamerica among the Aztecs and Maya.[11] It is still used by many Zoroastrian communities.
The vague year, from annus vagus or wandering year, is an integral approximation to the year equaling 365 days, which wanders in relation to more exact years. Typically the vague year is divided into 12 schematic months of 30 days each plus 5 epagomenal days. The vague year was used in the calendars of Ethiopia, Ancient Egypt, Iran, Armenia and in Mesoamerica among the Aztecs and Maya.[11] It is still used by many Zoroastrian communities.
Heliacal year - Sothic year
Sothic year - The Sothic year is the interval between heliacal risings of the star Sirius. It is currently less than the sidereal year and its duration is very close to the Julian year of 365.25 days.
The Sothic year is the interval between heliacal risings of the star Sirius. It is currently less than the sidereal year and its duration is very close to the Julian year of 365.25 days.
Gaussian year - The Gaussian year is the sidereal year for a planet of negligible mass (relative to the Sun) and unperturbed by other planets that is governed by the Gaussian gravitational constant. Such a planet would be slightly closer to the Sun than Earth's mean distance. Its length is:
The Gaussian year is the sidereal year for a planet of negligible mass (relative to the Sun) and unperturbed by other planets that is governed by the Gaussian gravitational constant. Such a planet would be slightly closer to the Sun than Earth's mean distance. Its length is:
365.2568983 days (365 d 6 h 9 min 56 s).
Besselian year - The Besselian year is a tropical year that starts when the (fictitious) mean Sun reaches an ecliptic longitude of 280. This is currently on or close to January 1. It is named after the 19th-century German astronomer and mathematician Friedrich Bessel. The following equation can be used to compute the current Besselian epoch (in years):[12]
The Besselian year is a tropical year that starts when the (fictitious) mean Sun reaches an ecliptic longitude of 280. This is currently on or close to January 1. It is named after the 19th-century German astronomer and mathematician Friedrich Bessel. The following equation can be used to compute the current Besselian epoch (in years):[12]
The TT subscript indicates that for this formula, the Julian date should use the Terrestrial Time scale, or its predecessor, ephemeris time.
The exact length of an astronomical year changes over time.
The positions of the equinox and solstice points with respect to the apsides of Earth's orbit change: the equinoxes and solstices move westward relative to the stars because of precession, and the apsides move in the other direction because of the long-term effects of gravitational pull by the other planets. Since the speed of the Earth varies according to its position in its orbit as measured from its perihelion, Earth's speed when in a solstice or equinox point changes over time: if such a point moves toward perihelion, the interval between two passages decreases a little from year to year; if the point moves towards aphelion, that period increases a little from year to year. So a "tropical year" measured from one passage of the northward ("vernal") equinox to the next, differs from the one measured between passages of the southward ("autumnal") equinox. The average over the full orbit does not change because of this, so the length of the average tropical year does not change because of this second-order effect.
Each planet's movement is perturbed by the gravity of every other planet. This leads to short-term fluctuations in its speed, and therefore its period from year to year. Moreover, it causes long-term changes in its orbit, and therefore also long-term changes in these periods.
Tidal drag between the Earth and the Moon and Sun increases the length of the day and of the month (by transferring angular momentum from the rotation of the Earth to the revolution of the Moon); since the apparent mean solar day is the unit with which we measure the length of the year in civil life, the length of the year appears to decrease. The rotation rate of the Earth is also changed by factors such as post-glacial rebound and sea level rise.
Numerical value of year variation - Mean year lengths in this section are calculated for 2000, and differences in year lengths, compared to 2000, are given for past and future years. In the tables a day is 86,400 SI seconds long.[13][14][15][16]
Mean year lengths in this section are calculated for 2000, and differences in year lengths, compared to 2000, are given for past and future years. In the tables a day is 86,400 SI seconds long.[13][14][15][16]
Year length difference from 2000 (seconds; positive when length for tabulated year is greater than length in 2000)
An average Gregorian year is 365.2425 days (52.1775 weeks, 8765.82 hours, 525949.2 minutes or 31556952 seconds). For this calendar, a common year is 365 days (8760 hours, 525600 minutes or 31536000 seconds), and a leap year is 366 days (8784 hours, 527040 minutes or 31622400 seconds). The 400-year cycle of the Gregorian calendar has 146097 days and hence exactly 20871 weeks.
"Greater" astronomical years - Equinoctial cycle
Equinoctial cycle - The Great Year, or equinoctial cycle, corresponds to a complete revolution of the equinoxes around the ecliptic. Its length is about 25,700 years.
The Great Year, or equinoctial cycle, corresponds to a complete revolution of the equinoxes around the ecliptic. Its length is about 25,700 years.
Seasonal year - A seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.
A seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.
Symbols - A common symbol for the year as a unit of time is a, taken from the Latin word annus. In English, the abbreviations "y" or "yr" are more commonly used in non-scientific literature but also specifically in geology and paleontology, where "kyr, myr, byr" (thousands, millions, and billions of years, respectively) and similar abbreviations are used to denote intervals of time remote from the present.[18][19][20]
A common symbol for the year as a unit of time is a, taken from the Latin word annus. In English, the abbreviations "y" or "yr" are more commonly used in non-scientific literature but also specifically in geology and paleontology, where "kyr, myr, byr" (thousands, millions, and billions of years, respectively) and similar abbreviations are used to denote intervals of time remote from the present.[18][19][20]
Symbol - NIST SP811[21] supports the symbol a as the unit of time for a year. In English, the abbreviations y and yr are also used.[18][19][20]
NIST SP811[21] supports the symbol a as the unit of time for a year. In English, the abbreviations y and yr are also used.[18][19][20]
a = 31556925.445 seconds (approximately 365.24219265 ephemeris days)
This differs from the above definition of 365.25 days by about 20 parts per million. The joint document says that definitions such as the Julian year "bear an inherent, pre-programmed obsolescence because of the variability of Earths orbital movement", but then proposes using the length of the tropical year as of 2000 AD (specified down to the millisecond), which suffers from the same problem.[24][25] (The tropical year oscillates with time by more than a minute.)
The notation has proved controversial as it conflicts with an earlier convention among geoscientists to use a specifically for years ago, and y or yr for a one-year time period.[25]
SI prefix multipliers - For the following, there are alternative forms that elide the consecutive vowels, such as kilannus, megannus, etc. The exponents and exponential notations are typically used for calculating and in displaying calculations, and for conserving space, as in tables of data.
For the following, there are alternative forms that elide the consecutive vowels, such as kilannus, megannus, etc. The exponents and exponential notations are typically used for calculating and in displaying calculations, and for conserving space, as in tables of data.
Ma (for megaannum) a unit of time equal to one million, or 106, years, or 1 E6 yr. The suffix "Ma" is commonly used in scientific disciplines such as geology, paleontology, and celestial mechanics to signify very long time periods into the past or future. For example, the dinosaur species Tyrannosaurus rex was abundant approximately 66 Ma (66 million years) ago. The duration term "ago" may not always be indicated: if the quantity of a duration is specified while not explicitly mentioning a duration term, one can assume that "ago" is implied; the alternative unit "mya" does include "ago" explicitly. It is also written as "million years" (ago) in works for general public use. In astronomical applications, the year used is the Julian year of precisely 365.25 days. In geology and paleontology, the year is not so precise and varies depending on the author.
Ga (for gigaannum) a unit of time equal to 109 years, or one billion years. "Ga" is commonly used in scientific disciplines such as cosmology and geology to signify extremely long time periods in the past.[26] For example, the formation of the Earth occurred approximately 4.54 Ga (4.54 billion years) ago and the age of the universe is approximately 13.8 Ga.
Ta (for teraannum) a unit of time equal to 1012 years, or one trillion years. "Ta" is an extremely long unit of time, about 70 times as long as the age of the universe. It is the same order of magnitude as the expected life span of a small red dwarf.
Pa (for petaannum) a unit of time equal to 1015 years, or one quadrillion years. The half-life of the nuclide cadmium-113 is about 8 Pa.[27] This symbol coincides with that for the pascal without a multiplier prefix, though both are infrequently used and context will normally be sufficient to distinguish time from pressure values.
Ea (for exaannum) a unit of time equal to 1018 years, or one quintillion years. The half-life of tungsten-180 is 1.8 Ea.[28]
Abbreviations yr and ya - In astronomy, geology, and paleontology, the abbreviation yr for years and ya for years ago are sometimes used, combined with prefixes for thousand, million, or billion.[19][29] They are not SI units, using y to abbreviate the English "year", but following ambiguous international recommendations, use either the standard English first letters as prefixes (t, m, and b) or metric prefixes (k, M, and G) or variations on metric prefixes (k, m, g). In archaeology, dealing with more recent periods, normally expressed dates, e.g. "22,000 years ago" may be used as a more accessible equivalent of a Before Present ("BP") date.
In astronomy, geology, and paleontology, the abbreviation yr for years and ya for years ago are sometimes used, combined with prefixes for thousand, million, or billion.[19][29] They are not SI units, using y to abbreviate the English "year", but following ambiguous international recommendations, use either the standard English first letters as prefixes (t, m, and b) or metric prefixes (k, M, and G) or variations on metric prefixes (k, m, g). In archaeology, dealing with more recent periods, normally expressed dates, e.g. "22,000 years ago" may be used as a more accessible equivalent of a Before Present ("BP") date.
Use of mya and bya is deprecated in modern geophysics, the recommended usage being Ma and Ga for dates Before Present, but "m.y." for the duration of epochs.[19][20] This ad hoc distinction between "absolute" time and time intervals is somewhat controversial amongst members of the Geological Society of America.[31]
Note that on graphs, using ya units on the horizontal axis time flows from right to left, which may seem counter-intuitive. If the ya units are on the vertical axis, time flows from top to bottom which is probably easier to understand than conventional notation.[clarification needed]
References - Notes
Notes - ^ "SI units". IAU. Retrieved February 18, 2010. (See Table 5 and Section 5.15.) Reprinted from: Wilkins, George A. (1989). "The IAU Style Manual" (PDF). IAU Transactions. XXB.
^ "SI units". IAU. Retrieved February 18, 2010. (See Table 5 and Section 5.15.) Reprinted from: Wilkins, George A. (1989). "The IAU Style Manual" (PDF). IAU Transactions. XXB.
^ OED, s.v. "year", entry 2.b.: "transf. Applied to a very long period or cycle (in chronology or mythology, or vaguely in poetic use)."
^ Shields, Miriam Nancy (1924). "The new calendar of the eastern churches". Popular Astronomy. 32: 407. Bibcode:1924PA.....32..407S.
^ Ziggelaar, A. (1983). "The Papal Bull of 1582 Promulgating a Reform of the Calendar". In G. V. Coyne; M. A. Hoskin; O. Pedersen (eds.). Gregorian Reform of the Calendar: Proceedings of the Vatican Conference to Commemorate its 400th Anniversary. Vatican City: Pontifical Academy of Sciences. p. 223.
^ Richards, E.G. (2013). "Calendars". In Urban, S.E.; Seidelmann, P.K. (eds.). Explanatory Supplement to the Astronomical Almanac (PDF) (3rd ed.). Mill Valley, CA: University Science Books. pp. 585, 590. ISBN 978-1-891389-85-6. Richards does not explicitly say that Anno Domini is the worldwide standard, but does say on page 585 that the Gregorian calendar is used throughout the world for secular purposes.
^ Richards, E.G. (2013). Calendars. In S.E. Urban & P.K. Seidelmann (Eds.), Explanatory Supplement to the Astronomical Almanac (3rd ed.). Mill Valley, CA: University Science Books. p. 586.
^ Astronomical Almanac for the Year 2011. Washington and Taunton: U.S. Government Printing Office and the U.K. Hydrographic Office. 2009. p. M18 (Glossary).
^ U.S. Naval Observatory Nautical Almanac Office and Her Majesty's Nautical Almanac Office (2010). Astronomical Almanac for the year 2011. Washington: U.S. Government Printing Office. pp. C2, L8.
^ Simon, J.L.; Bretagnon, P.; Chapront, J.; Chapront-Touz, M.; Francou, G.; Laskar, J. (February 1994). "Numerical expressions for precession formulae and mean elements for the Moon and planets". Astronomy and Astrophysics. 282 (2): 663683. Bibcode:1994A&A...282..663S.
^ Taff, Lawrence G. (1985). Celestial Mechanics: A Computational Guide for the Practitioner. New York: John Wiley & Sons. p. 103. ISBN 978-0-471-89316-5. Values in tables agree closely for 2000, and depart by as much as 44 seconds for the years furthest in the past or future; the expressions are simpler than those recommended in the Astronomical Almanac for the Year 2011.
^ Seidelmann, P. Kenneth (2013). Explanatory Supplement to the Astronomical Almanac. Sean E. Urban (ed.) (3 ed.). Univ Science Books. p. 587. ISBN 978-1-891389-85-6. Tabulates length of tropical year from 500 to 2000 at 500 year intervals using a formula by Laskar (1986); agrees closely with values in this section near 2000, departs by 6 seconds in 500.
^ a b Rowlett, Russ. "Units: A". How Many? A Dictionary of Units of Measurement. University of North Carolina. Retrieved January 9, 2009.
^ a b c North American Commission on Stratigraphic Nomenclature (November 2005). "North American Stratigraphic Code". The American Association of Petroleum Geologists Bulletin (Article 13 (c) ed.). 89 (11): 15471591. doi:10.1306/07050504129.
^ North American Commission on Stratigraphic Nomenclature. "North American Stratigraphic Code (Article 13 (c))". (c) Convention and abbreviations. The age of a stratigraphic unit or the time of a geologic event, as commonly determined by numerical dating or by reference to a calibrated time-scale, may be expressed in years before the present. The unit of time is the modern year as presently recognized worldwide. Recommended (but not mandatory) abbreviations for such ages are SI (International System of Units) multipliers coupled with "a" for annus: ka, Ma, and Ga for kilo-annus (103 years), Mega-annus (106 years), and Giga-annus (109 years), respectively. Use of these terms after the age value follows the convention established in the field of C-14 dating. The "present" refers to AD 1950, and such qualifiers as "ago" or "before the present" are omitted after the value because measurement of the duration from the present to the past is implicit in the designation. In contrast, the duration of a remote interval of geologic time, as a number of years, should not be expressed by the same symbols. Abbreviations for numbers of years, without reference to the present, are informal (e.g., y or yr for years; my, m.y., or m.yr. for millions of years; and so forth, as preference dictates). For example, boundaries of the Late Cretaceous Epoch currently are calibrated at 63 Ma and 96 Ma, but the interval of time represented by this epoch is 33 m.y. Cite journal requires (help)
^ "Time Units". Geological Society of America. Archived from the original on June 16, 2016. Retrieved February 17, 2010.
Accessibility in the built environment - Developers, designers and owners of buildings have a responsibility to ensure that the built environment is accessible to everyone wherever it is practical to do so. This includes anyone who has a mobility or other impairment, whether permanent or temporary, such as:
Developers, designers and owners of buildings have a responsibility to ensure that the built environment is accessible to everyone wherever it is practical to do so. This includes anyone who has a mobility or other impairment, whether permanent or temporary, such as:
Wheelchair users, their carers, people with walking difficulties and so on.
People with pushchairs and children. - People with sight or hearing impairments.
People with sight or hearing impairments. - Elderly people.
Elderly people. - People with co-ordination or respiratory problems.
People with co-ordination or respiratory problems. - Part M of the Buildings Regulations, Access to and Use of Buildings, sets out legal minimum requirements for works to buildings or new buildings. Whereas previous versions of the Regulations focused on the specific needs of people with disabilities, the current edition promotes an approach to inclusive design that reflects the needs of all people, requiring that:
Part M of the Buildings Regulations, Access to and Use of Buildings, sets out legal minimum requirements for works to buildings or new buildings. Whereas previous versions of the Regulations focused on the specific needs of people with disabilities, the current edition promotes an approach to inclusive design that reflects the needs of all people, requiring that:
M1, Access to and use of buildings other than dwellings: Reasonable provision shall be made for people to: (a) gain access to; and (b) use the building and its facilities.
M2, Access to extensions to buildings other than dwellings: Suitable independent access shall be provided to the extension where reasonably practicable.
M3, Sanitary conveniences in extensions to buildings other than dwellings: If sanitary conveniences are provided in any building that is to be extended, reasonable provision shall be made within the extension for sanitary conveniences.
M4 (1), Visitable dwellings: Reasonable provision should be made for people to (a) gain access to; and (b) use, the dwelling and its facilities.
M4(2), Accessible and adaptable dwellings, optional requirement (1): Reasonable provision must be made for people to (a) gain access to; and (b) use, the dwelling and its facilities. (2): The provision made must be sufficient to (a) meet the needs of occupants with differing needs, including some older or disabled people; and (b) to allow adaptation of the dwelling to meet the changing needs of occupants over time.
M4(3), Wheelchair user dwellings, optional requirement (1): Reasonable provision must be made for people to (a) gain access to, and (b) use, the dwelling and its facilities. (2): The provision made must be sufficient to (a) allow simple adaptation of the dwelling to meet the needs of occupants who use wheelchairs; or (b) meet the needs of occupants who use wheelchairs.
Approved document M - Common approaches that can be adopted to demonstrate compliance with these requirements are set out in Approved Document M, Access to and use of buildings.
Common approaches that can be adopted to demonstrate compliance with these requirements are set out in Approved Document M, Access to and use of buildings.
The Approved Document suggests that the term 'accessible' means '...that people, regardless of disability, age or gender, are able to gain access.'
The 2015 edition of the Approved Document is provided in two volumes:
Volume 1 - Access to and use of dwellings
This introduces three different types of dwelling: -
Category 1 - Visitable dwellings. - Category 2 - Accessible and adaptable dwellings.
Category 2 - Accessible and adaptable dwellings. - Category 3 - Wheelchair user dwellings.
Category 3 - Wheelchair user dwellings. - It provides guidance on; the approach to the dwelling and private entrances and spaces within the dwelling.
It provides guidance on; the approach to the dwelling and private entrances and spaces within the dwelling.
Volume 2 - Access to and use of buildings other than dwellings
Volume 2 provides guidance on: -
Access. - Horizontal and vertical circulation.
Horizontal and vertical circulation. - Facilities.
Facilities. - Sanitary accommodation
Sanitary accommodation - Accessibility in existing buildings
Accessibility in existing buildings - Dwellings
Dwellings - Where a dwelling is subject to a material alteration, the building should be no less compliant with requirement M4(1) than it was prior to the building work taking place.
Where a dwelling is subject to a material alteration, the building should be no less compliant with requirement M4(1) than it was prior to the building work taking place.
Buildings other than dwellings - Volume 2 applies where:
Volume 2 applies where: -
a non-domestic building is newly erected; - an existing non-domestic building is extended, or undergoes a material alteration; or
an existing non-domestic building is extended, or undergoes a material alteration; or
an existing building or part of an existing building undergoes a material change of use to a hotel or boarding house, institution, public building or shop.
Where works are carried out on existing buildings, the works themselves must comply with the regulations. Reasonable provision must be made for people to gain access to and to use new or altered sanitary conveniences. The building as a whole, including access to it from the site boundary and from on-site car parking where provided, must be no less compliant with requirement M1 following a material alteration of a building. It is not necessary to upgrade access to the building entrance from the site boundary and from on-site car parking where provided (although, see other considerations below).
Where there is a material change of use of the whole of a building to a hotel or boarding house, an institution, a public building or a shop, the building must be upgraded, if necessary, so as to comply with rquirement M1.
Where works are carried out to historic buildings, they should aim to improve accessibility where and to the extent that it is practically possible, provided that the work does not prejudice the character of the historic building, or increase the risk of long-term deterioration to the building fabric or fittings.
Other considerations - The Workplace (Health, Safety and Welfare) Regulations 1992 Approved Code of Practice and guidance states:
The Workplace (Health, Safety and Welfare) Regulations 1992 Approved Code of Practice and guidance states:
'Regardless of their disability, people should be able to gain access to buildings and use the facilities. This could mean that an employer may need to make some changes to a building or premises to take account of the disabled person's needs.'
Furthermore, the Equality Act 2010 requires that 'reasonable adjustments' are made when providing access to goods, facilities, services and premises.
These adjustments could include: -
The structure of a building such as the steps, changes of level, emergency exits or narrow doorways.
Handrails for disabled people who may find it easier to negotiate a flight of stairs than a ramp.
Avoiding heavy doors, inaccessible toilets or inappropriate lighting.
Installing suitable toilet facilities, either specially designed cubicles in separate-sex bathrooms or a self-contained unisex toilet.
In workplaces, workstation access may need to be modified in terms of width and height to accommodate wheelchair users for instance.
The Equality and Human Rights Commission suggests with regard to making reasonable adjustments to premises:
'An employer makes structural or other physical changes such as widening a doorway, providing a ramp or moving furniture for a wheelchair user; relocates light switches, door handles, or shelves for someone who has difficulty in reaching; or provides appropriate contrast in decor to help the safe mobility of a visually impaired person.'
With regard to what is 'reasonable', the considerations can be:
How effective the change will be. - Its practicality.
Its practicality. - The cost.
The cost. - The organisation's resources and size.
The organisation's resources and size. - The availability of financial support.
The availability of financial support. - Access consultants
Access consultants - Access consultants can provide professional advice on how to develop accessible environments.
Access consultants can provide professional advice on how to develop accessible environments.
See Access consultant for more information. -
An access audit can be helpful in assessing the ease of access to, and ease of use of an environment, a service, or a facility, by people with a range of access impairments. This can help demonstrate compliance with legislation and identify areas where changes may be appropriate.
See Access audit for more information. -
Inclusive design - The British Standards Institute (2005) defines inclusive design as "The design of mainstream products and/or services that are accessible to, and usable by, as many people as reasonably possible ... without the need for special adaptation or specialised design."
The British Standards Institute (2005) defines inclusive design as "The design of mainstream products and/or services that are accessible to, and usable by, as many people as reasonably possible ... without the need for special adaptation or specialised design."
CABE have published and promoted the principles of inclusive design as it relates to the built environment:
Inclusive - so everyone can use it safely, easily and with dignity.
Responsive - taking account of what people say they need and want.
Flexible - so different people can use it in different ways.
Convenient - so everyone can use it without too much effort or separation.
Accommodating for all people, regardless of their age, gender, mobility, ethnicity or circumstances.
Welcoming - with no disabling barriers that might exclude some people.
Realistic - offering more than one solution to help balance everyone's needs and recognising that one solution may not work for all.
For more information see Inclusive design. -
Universal design - The principles of universal design provide a broad conceptual starting point for the underpinning ethos of inclusive design:
The principles of universal design provide a broad conceptual starting point for the underpinning ethos of inclusive design:
Equitable use. - Flexibility in use.
Flexibility in use. - Simple and intuitive
Simple and intuitive - Perceptible information.
Perceptible information. - Tolerance for error.
Tolerance for error. - Low physical effort.
Low physical effort. - Size and space for approach and use.
Size and space for approach and use. - However, there has been criticism that these are too vague to be applied practically in practice. The problems that occur in the built environment are complex and often interlinked. Isolating one individual element may allow the principles to be used, but when viewed as a larger picture issues beyond the designer's control confound the principles.
However, there has been criticism that these are too vague to be applied practically in practice. The problems that occur in the built environment are complex and often interlinked. Isolating one individual element may allow the principles to be used, but when viewed as a larger picture issues beyond the designer's control confound the principles.
See Universal Design for more information. -
The term `area' generally refers to a two-dimensional extent or measurement of land or some other surface, or part of a region. Typically, it is used to measure the two-dimensional surface of a three-dimensional object, i.e. a building.
Squares of a fixed size are used to measure the area of a shape, and as per the International System of Units (SI), the standard unit of area is the square metre (m2 or sq. m). The square metre measurement indicates the area contained within a square whose sides are all 1 m long.
In terms of buildings, area is commonly measured and referred to in relation to the two-dimensional space of a floor or wall. For example, it is used to calculate the amount of paint that would be required to cover a wall surface (with a single coat of a given thickness), or the amount of carpet that would be required to cover a floor surface.
The Building Regulations define floor area as `...the aggregate area of every floor in a building or extension, calculated by reference to the finished internal faces of the walls enclosing the area, or if at any point there is no such wall, by reference to the outermost edge of the floor.'
The area of a building can be measured in a number of different ways:
Gross external area (GEA): the whole area of a building taking each floor into account, including perimeter walls.
Gross internal area (GIA): the area of a building measured to the internal face of the perimeter walls at each floor level. (Also known as the total useful floor area.)
Net internal area (NIA): the usable area measured to the internal finish of the perimeter or party walls at each floor level.
The floor area ratio (FAR), also known as the plot ratio, is a measure of the total permitted floor area of a building, in relation to the total area of the plot on which the building stands. A higher ratio indicates a higher-density.
Area can also refer to different places and spaces within a building. For example, an ancillary area of a building is an area that supports the function/s of the primary areas, that is, it is not part of the primary purpose of the building, but is required in order that the primary purpose can function. The term `common area' refers to areas and amenities which are provided for the common use of more than one person.
Designing Buildings Wiki has a range of articles about different types of area, including:
Area of outstanding natural beauty - Coastal change management area
Coastal change management area - Conservation area
Conservation area - Covered area
Covered area - Designated area
Designated area - Edge of centre
Edge of centre - Enterprise zone.
Enterprise zone. - How to fit carpet.
How to fit carpet. - Mineral safeguarding area
Mineral safeguarding area - Nature improvement area
Nature improvement area - Open space
Open space - Opportunity Area Planning Framework (OAPF)
Opportunity Area Planning Framework (OAPF) - Primary shopping area.
Primary shopping area. - Public space.
Public space. - Site area
Site area - Special areas of conservation.
Special areas of conservation. - Town centre.
Town centre. - Types of room.
Types of room. - Unprotected area.
Unprotected area. -
What is array? - Noun
Noun - S: (n) array (an orderly arrangement) "an array of troops in battle order"
S: (n) array (an orderly arrangement) "an array of troops in battle order"
S: (n) array (an impressive display) "it was a bewildering array of books"; "his tools were in an orderly array on the basement wall"
S: (n) array, raiment, regalia (especially fine or decorative clothing)
S: (n) array (an arrangement of aerials spaced to give desired directional characteristics)
Verb - S: (v) range, array, lay out, set out (lay out orderly or logically in a line or as if in a line) "lay out the clothes"; "lay out the arguments"
S: (v) range, array, lay out, set out (lay out orderly or logically in a line or as if in a line) "lay out the clothes"; "lay out the arguments"
S: (v) align, array (align oneself with a group or a way of thinking)
At grade - `Grade is a term used to describe the level of the earth at a specific location or at ground level. In construction, the terms `above grade' and `below grade' can be used respectively to describe the portion of a building that is above or below the ground. In tunnelling, the invert of a tunnel may be described as being 25m below grade or ground level.
`Grade is a term used to describe the level of the earth at a specific location or at ground level. In construction, the terms `above grade' and `below grade' can be used respectively to describe the portion of a building that is above or below the ground. In tunnelling, the invert of a tunnel may be described as being 25m below grade or ground level.
In the US, an `at grade' intersection will have roads or rail tracks - or a combination of both - arranged on the same level. Where a road and rail track intersect at grade, a level crossing will normally be in place. A river may also be said to be at grade (or level) with the land (as opposed to being in a deep valley).
The attachment/overlay status of this link.
Syntax: - C#
C# - public AttachmentType AttachmentType { get; set; }
public AttachmentType AttachmentType { get; set; }
Visual Basic - Public Property AttachmentType As AttachmentType
Public Property AttachmentType As AttachmentType - Get
Get - Set
Set - Visual C++
Visual C++ - public:
public: - property AttachmentType AttachmentType {
property AttachmentType AttachmentType { - AttachmentType get ();
AttachmentType get (); - void set (AttachmentType value);
void set (AttachmentType value); - }
} -
Field Value - AttachmentType.Overlay if this link is an overlay, AttachmentType.Attachment if this link is an attachment.
AttachmentType.Overlay if this link is an overlay, AttachmentType.Attachment if this link is an attachment.
Remarks - "Attachment" links are considered to be part of their parent link and will be brought along if their parent is linked into another document. "Overlay" links are only visible when their parent is open directly.
"Attachment" links are considered to be part of their parent link and will be brought along if their parent is linked into another document. "Overlay" links are only visible when their parent is open directly.
For example: A user has a file B which contains a link C, and they wish to link B into another file, A. If C is an overlay, C will not be loaded into A. If C is an attachment, then C will be loaded into A along with B.
Introduction - Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics to support them.
Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics to support them.
There are a very wide range of foundation types suitable for different applications, depending on considerations such as:
The nature of the load requiring support. - Ground conditions.
Ground conditions. - The presence of water.
The presence of water. - Space availability.
Space availability. - Accessibility.
Accessibility. - Sensitivity to noise and vibration.
Sensitivity to noise and vibration. - Very broadly, foundations can be categorised as shallow foundations or deep foundations.
Very broadly, foundations can be categorised as shallow foundations or deep foundations.
Shallow foundations are typically used where the loads imposed by a structure are low relative to the bearing capacity of the surface soils.
Deep foundations are necessary where the bearing capacity of the surface soils is not adequate to support the loads imposed by a structure and so those loads need to be transferred to deeper layers with higher bearing capacity.
Types of shallow foundations: - Strip foundations provide a continuous strip of support to a linear structure such as a wall. For more information, see Strip foundation.
Strip foundations provide a continuous strip of support to a linear structure such as a wall. For more information, see Strip foundation.
Trench fill foundations are a variation of strip foundations, in which the trench excavation is almost completely filled with concrete. For more information see: Trench fill foundation.
Rubble trench foundations are a further variation of trench fill foundations, and are a traditional construction method which uses loose stone or rubble to minimise the use of concrete and improve drainage. For more information, see Rubble trench foundations.
Pad foundations - Pad foundations are rectangular or circular pads used to support localised loads such as columns. For more information, see Pad foundations.
Pad foundations are rectangular or circular pads used to support localised loads such as columns. For more information, see Pad foundations.
Raft foundations - Raft foundations are slabs that cover a wide area, often the entire footprint of a building, and are suitable where ground conditions are poor, settlement is likely, or where it may be impractical to create individual strip or pad foundations for a large number of individual loads. Raft foundations may incorporate beams or thickened areas to provide additional support for specific loads. For more information, see Raft foundations.
Raft foundations are slabs that cover a wide area, often the entire footprint of a building, and are suitable where ground conditions are poor, settlement is likely, or where it may be impractical to create individual strip or pad foundations for a large number of individual loads. Raft foundations may incorporate beams or thickened areas to provide additional support for specific loads. For more information, see Raft foundations.
Types of deep foundation: - Pile foundations are long, slender, columns typically made from steel or reinforced concrete, or sometimes timber.
Pile foundations are long, slender, columns typically made from steel or reinforced concrete, or sometimes timber.
Generally piles are classified as; end-bearing piles (where most of the friction is developed at the toe of the pile, bearing on a hard layer), or friction piles (where most of the pile-bearing capacity is developed by shear stresses along the sides of the pile, suitable when harder layers are too deep).
Piles are most commonly; driven piles prefabricated off site and then driven into the ground, or bored piles that are poured in situ. If the boring and pouring takes place simultaneously, the piles are called continuous fight augured (CFA) piles.
Mini piles are used where access is restricted, for example underpinning structures affected by settlement. They can be driven or screw piles.
By placing piles directly adjacent to one another, a permanent or temporary retaining wall can be created. These can be closely-spaced contiguous pile walls, or interlocking secant walls, which depending on the composition of the secondary intermediate piles can be hard/soft, hard/firm or hard/hard secant walls.
Diaphragm walls are made by excavating a deep trench that is prevented from collapsing by being filled with engineering slurry such as bentonite and then the trench is filled with reinforced concrete panels, the joints between which can be water-tight.
This is commonly used for top-down construction, where a basement is constructed at the same time as above ground works are carried out.
Caissons are watertight retaining structures sunk into the ground by removing material from the bottom, typically this might be suitable for building structures below water level. For more information, see Caisson.
Compensated foundations - If a very large amount of material is excavated (for example, where there is a deep basement), it may be sufficient that the relief of stress due to the excavation is equal to the applied stress from the new construction. As a result, there should be little effective change in stress and little settlement.
If a very large amount of material is excavated (for example, where there is a deep basement), it may be sufficient that the relief of stress due to the excavation is equal to the applied stress from the new construction. As a result, there should be little effective change in stress and little settlement.
For more information, see Compensated foundation. -
Ground anchors - Ground anchors transfer very high loads by using a grouted anchor to mechanically transfer load from a tendon to the ground. They can be pre-tensioned, or can be tensioned by the applied load.
Ground anchors transfer very high loads by using a grouted anchor to mechanically transfer load from a tendon to the ground. They can be pre-tensioned, or can be tensioned by the applied load.
Definition - Defining different building levels is a way to analyse buildings by breaking them down into successively smaller or simpler units, e.g. into elements, components and materials.
Defining different building levels is a way to analyse buildings by breaking them down into successively smaller or simpler units, e.g. into elements, components and materials.
However, depending on the purpose of the analysis, buildings can be broken down in various ways, e.g. by functional, physical, legal or economic characteristics. Accordingly, a common terminology could not be developed.
Guidelines - Whenever the deconstruction of a building into successively smaller parts is proposed or adopted, further clarification will be indispensable. Only for the levels `building' and `material' could a general definition be found. The levels in-between both vary according to the purpose.
Whenever the deconstruction of a building into successively smaller parts is proposed or adopted, further clarification will be indispensable. Only for the levels `building' and `material' could a general definition be found. The levels in-between both vary according to the purpose.
The necessary clarification should not only present the introduced hierarchy and the different levels it includes. Also, the characteristics that determine to which level a certain assembly or part belongs should be defined unambiguously.
Because of the consistent interpretation of their meaning throughout different domains, the use of terms `part' and `assembly' is encouraged. Nevertheless, for both terms it is useful to clarify whereof and of what the considered unit is a part or assembly. After all, every unit can be a part of a larger part and the assembly of several smaller assemblies at the same time. For instance, a window, an assembly of parts such as glass panes and aluminium profiles, is only a part of the building faade.
It is impossible to define unambiguously the however frequently used terms `component' and `element'. If these terms would be used for one or more specific purposes, a corresponding definition should be provided in this common language.
Building performance - Building performance.jpg
Building performance.jpg - Contents
Contents - 1 Introduction
1 Introduction - 2 Evaluating building performance
2 Evaluating building performance - 3 Building regulations
3 Building regulations - 4 Performance gap
4 Performance gap - 5 Performance specifications
5 Performance specifications - 6 KPIs
6 KPIs - 7 Certification
7 Certification - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - Introduction
Introduction - A building's performance (or efficiency) is a measure of how well it functions in relation to designated criteria such as physical, social or environmental considerations. For example, a building's physical efficiency might be evaluated by assessing parameters such as heat loss, energy use, water use, water tightness, structural performance, fire performance and so on. It can also measure whether the resources necessary to design and construct a building have been used effectively.
A building's performance (or efficiency) is a measure of how well it functions in relation to designated criteria such as physical, social or environmental considerations. For example, a building's physical efficiency might be evaluated by assessing parameters such as heat loss, energy use, water use, water tightness, structural performance, fire performance and so on. It can also measure whether the resources necessary to design and construct a building have been used effectively.
Assessments can be made for all building types and are particularly important in housing. Concerns about how buildings perform date back at least as far as Neolithic times. Cave dwellers would assess their habitat against criteria such as; shelter from the elements, safety against animal attack, conspicuity, and solar orientation. Similar concerns have preoccupied people ever since, but the list has grown with increasing construction complexity and tighter regulatory requirements.
Evaluating building performance - Today building performance might be assessed against criteria including:
Today building performance might be assessed against criteria including:
Sustainability (are the materials environmentally friendly? How much energy is used to heat/cool the building? How well does the building fabric retain heat (linked to insulation levels and glazing performance)? Is the building water efficient (does it include grey-water recycling)?
Comfort - can air temperatures, humidity and ventilation achieve a healthy environment?
Ecology - is there a negative or positive impact on habitats?
Acoustics - does noise generated by activities in the building adversely affect neighbouring buildings or spaces and vice versa?
Running costs - how much does it cost to run the building?
Water tightness - are roofs and openings capable of keeping out rain and other sources of moisture?
Layout - does the building optimise privacy, sunlight, views, occupant circulation and so on?
Occupant satisfaction - are the occupants satisfied with the overall resolution of the design?
Accessibility - is the building easy to use by people with disabilities? Is it safe and secure?
Society - does the building integrate with and contribute to the local community?
Building regulations - The first set of national building standards was introduced in 1965. Now known as the Building Regulations, they set out minimum requirements for specific aspects of building design and construction.
The first set of national building standards was introduced in 1965. Now known as the Building Regulations, they set out minimum requirements for specific aspects of building design and construction.
For more information see: Building regulations. -
Performance gap - The way some buildings perform when completed may not live up to the designers' intentions. The difference between anticipated and actual performance may be significant and to the detriment of the occupiers, owners and environment. This is known as the performance gap which, if significant may result in aspects of the construction having to be redone and can lead to legal proceedings.
The way some buildings perform when completed may not live up to the designers' intentions. The difference between anticipated and actual performance may be significant and to the detriment of the occupiers, owners and environment. This is known as the performance gap which, if significant may result in aspects of the construction having to be redone and can lead to legal proceedings.
For more information see: Performance gap -
Performance specifications - Where building contracts include performance specifications, they will describe a particular required outcome, whether a specific U-value, ventilation requirement and so on that has to be achieved. It is then left to the suppliers to deliver those outcomes. In this situation, the nature of the performance required may be defined by the desired outcome, or by reference to standards.
Where building contracts include performance specifications, they will describe a particular required outcome, whether a specific U-value, ventilation requirement and so on that has to be achieved. It is then left to the suppliers to deliver those outcomes. In this situation, the nature of the performance required may be defined by the desired outcome, or by reference to standards.
For more information see: Performance specification. -
KPIs - Key performance indicators (KPIs) can provide a method for measuring performance. They can be used to:
Key performance indicators (KPIs) can provide a method for measuring performance. They can be used to:
Monitor costs. - Track progress.
Track progress. - Assess client satisfaction.
Assess client satisfaction. - Identify strengths and weaknesses.
Identify strengths and weaknesses. - Compare performance across and between projects.
Compare performance across and between projects. - Assess specific areas of a project such as sustainability, safety, waste management, etc.
Assess specific areas of a project such as sustainability, safety, waste management, etc.
If clients intend to measure the performance of suppliers, it is important that KPIs are identified in tender documentation and that the regular provision of the information required to assess them is a requirement of the contract. KPIs may be of particular importance where the contract stipulates that the contractor will be rewarded or penalised based on their performance relative to certain indicators.
For more information see: Key performance indicators.
Certification - A number of third-party schemes are available to certify the performance of buildings, such as:
A number of third-party schemes are available to certify the performance of buildings, such as:
Home Quality Mark. - BREEAM.
BREEAM. - Leadership in Energy and Environmental Design.
Leadership in Energy and Environmental Design. - Passivhaus.
Passivhaus. - SKA rating.
SKA rating. -
Revit measures the perimeter of a room at a defined distance above the base level of the room. This distance is the computation height.
It is used to compute the room perimeter, area, and volume. By default, the computation height is 0' or 0 mm above the base level of the room.
For buildings with vertical walls, the default computation height usually gives accurate results. However, if a building includes sloped walls or other atypical features, you may need to adjust the computation height to achieve more accurate room areas and volumes.
Materials include manufactured products such as components, fittings, items of equipment and systems; naturally occurring materials such as stone, timber and thatch; and backfilling for excavations in connection with building work.
NB Materials might also refer to project information material.
Narrower definitions of materials such as 'physical substances that things can be made from' would seem to exclude manufactured products such as components, fittings, items of equipment and systems. For example, steel is a material, whereas a steel beam is a product.
Primary materials are the materials that make up the majority of the structural components, foundation and envelope of construction projects. Ref The Living Building Challenge.
Some of the more commonly used construction materials that might be considered to fall within this narrower definition are listed below.
Adhesives - Adobe.
Adobe. - Acrylic.
Acrylic. - Aggregate
Aggregate - Alkali-activated binder
Alkali-activated binder - Aluminium.
Aluminium. - Architectural fabrics
Architectural fabrics - Asphalt
Asphalt - Bulk filling materials
Bulk filling materials - Carbon fibre
Carbon fibre - Cast iron
Cast iron - Cavity wall insulation
Cavity wall insulation - Cement
Cement - Ceramics
Ceramics - Chert
Chert - Clay
Clay - Coal ash
Coal ash - Concrete
Concrete - Concrete fibre
Concrete fibre - Copper.
Copper. - Daub
Daub - ETFE
ETFE - Fibre cement
Fibre cement - Glass for buildings
Glass for buildings - Glass reinforced concrete
Glass reinforced concrete - Glass reinforced plastic GRP
Glass reinforced plastic GRP - Glulam
Glulam - Graphene in civil engineering
Graphene in civil engineering - Gravel
Gravel - Gravel v hardcore v aggregates.
Gravel v hardcore v aggregates. - Grouting in civil engineering.
Grouting in civil engineering. - Gypsum.
Gypsum. - Hempcrete
Hempcrete - High alumina cement
High alumina cement - Icynene spray foam insulation
Icynene spray foam insulation - Laminated veneer lumber LVL
Laminated veneer lumber LVL - Lead in construction
Lead in construction - Limecrete
Limecrete - Masonry
Masonry - Mastic sealant
Mastic sealant - Metal
Metal - Mortar
Mortar - Mycelium
Mycelium - Nylon
Nylon - Oil - a global perspective
Oil - a global perspective - Paint
Paint - Paints and coatings
Paints and coatings - Pebbledash
Pebbledash - Phase change materials
Phase change materials - Phenolic foam insulation
Phenolic foam insulation - Plastic
Plastic - Plywood
Plywood - Polyamide intermediates
Polyamide intermediates - Polyethylene.
Polyethylene. - Polystyrene
Polystyrene - Polyurethane spray foam in structurally insulated panels and composite structures
Polyurethane spray foam in structurally insulated panels and composite structures
Polyvinyl chloride PVC - Precast concrete
Precast concrete - Prestressed concrete
Prestressed concrete - Products v goods v materials.
Products v goods v materials. - R22 phase out
R22 phase out - Recyclable construction materials
Recyclable construction materials - Refrigerants in buildings
Refrigerants in buildings - Reinforced concrete
Reinforced concrete - Render
Render - Renewable chemicals
Renewable chemicals - Sand.
Sand. - Solid wall insulation
Solid wall insulation - Stainless steel in construction
Stainless steel in construction - Steel
Steel - Stone.
Stone. - Straw bale construction
Straw bale construction - Structural steelwork
Structural steelwork - Stucco
Stucco - Sundry items.
Sundry items. - Sustainable materials
Sustainable materials - Terracotta.
Terracotta. - Thermoplastic materials in buildings
Thermoplastic materials in buildings - Timber
Timber - Topmix Permeable
Topmix Permeable - Tradical Hemcrete
Tradical Hemcrete - Transparent insulation
Transparent insulation - Types of steel
Types of steel - Wattle and daub
Wattle and daub - Wrought iron
Wrought iron - Zinc.
Zinc. -
Cords: - Main pieces, in composite supports, in sawn wood or in glued laminated wood.
Main pieces, in composite supports, in sawn wood or in glued laminated wood.
The length of a pipe segment is accurately modeled using separate joints. Cut length on the Properties palette is the actual length of the pipe and includes the depths needed to engage the flanges.
Cut length on Properties palette - Cut length refers to the distance between connectors inside a pipe segment. The following diagram differentiates pipe length from cut length, based on CEL (connector engagement length).
Cut length refers to the distance between connectors inside a pipe segment. The following diagram differentiates pipe length from cut length, based on CEL (connector engagement length).
The reported cut length value varies depending on the connection type of the attached fitting. For example, with hub flange couplings, the software considers the overall length of the connected object including the coupling length. The following example shows how the software reports the cut length based on this scenario. The overall calculated length includes the pipe length plus the coupling length.
Design life - The design life (or design service life) of a building, other structure or component, is the period of use as intended by the designer after which it may need to be replaced. Before this period has elapsed, it should remain fit for purpose.
The design life (or design service life) of a building, other structure or component, is the period of use as intended by the designer after which it may need to be replaced. Before this period has elapsed, it should remain fit for purpose.
Design life will vary according to the type and use of the element being considered. BS EN 1990, Eurocode - Basis of structural design, (Eurocode 0) gives indicative design lives for various types of structure:
Category 1: Temporary structures, not including structures or parts of structures that can be dismantled with a view to being re-used - 10 years.
Category 2: Replaceable structural parts, e.g. gantry girders, bearings - 10 to 25 years.
Category 3: Agricultural and similar buildings - 15 to 30 years.
Category 4: Building structures and other common structures - 50 years.
Category 5: Monumental building structures, bridges and other civil engineering structures - 100 years.
The design life of some components may be affected by environmental factors such as:
Moisture, humidity and rain. - Wind.
Wind. - Temperature and temperature fluctuations.
Temperature and temperature fluctuations. - Pollution.
Pollution. - Solar radiation.
Solar radiation. - It may also be affected by considerations such as maintenance practices, intensity of use, and so on.
It may also be affected by considerations such as maintenance practices, intensity of use, and so on.
There is no legally agreed definition of design life (in fact, there is not even a legally agreed definition of 'design'), so if it is to be included in contract documentation as a performance requirement, it is important that it is carefully defined within the contract documents and that it is consistent with all other requirements in the contract documents.
Several other definitions have been developed to quantify the life of buildings, structures and their components, including:
Required life. - Technical life.
Technical life. - Functional life.
Functional life. - Economic life.
Economic life. - Service life.
Service life. -
Duration - An activity is an operation or process consuming time and possibly other resources. An individual or work team can manage an activity. It is a measurable element of a programme.
An activity is an operation or process consuming time and possibly other resources. An individual or work team can manage an activity. It is a measurable element of a programme.
The term `duration' refers to the length of time needed to complete an activity. The time period can be determined inductively, by determining the start and finish date of an activity or deductively by calculation from the time necessary to expend the resources applied to the activity.
Controls where the elevation of the level is measured from. If the elevation base value is set to Project Base Point, the elevation is measured from the Project Base Point. If the base value is set to Survey Point, then the elevation is measured from the Survey Point.
Introduction - Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by `projecting' its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by `projecting' its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
In the construction industry, the term `elevation' refers to an orthographic projection of the exterior (or sometimes the interior) faces of a building, that is a two-dimensional drawing of the building's faades. As buildings are rarely simple rectangular shapes in plan, an elevation drawing is a first angle projection that shows all parts of the building as seen from a particular direction with the perspective flattened. Generally, elevations are produced for four directional views, for example, north, south, east, west.
Simple elevation drawings might show: -
The outline of a building. - Openings such as doors and windows.
Openings such as doors and windows. - Roofing.
Roofing. - Projections such as eves and pipes.
Projections such as eves and pipes. - Level datums such as finished ground level and floor positions.
Level datums such as finished ground level and floor positions.
Key dimensions such as wall lengths and heights.
Exterior features such as decks, porches and steps.
Any portion of the foundation that may be visible.
Exterior wall and roof finishes. - However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
Elevations might be prepared for a number of reasons, including:
As part of a survey of existing buildings.
To create a record of a building. - To explore and communicate interior and exterior design options.
To explore and communicate interior and exterior design options.
To communicate construction information. - As part of an application for planning permission.
As part of an application for planning permission.
As part of an application for building regulations approval.
For sales and marketing. - Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
Alternative meaning - The term 'elevation' might also be used to refer to the height of something above or below a fixed reference point or datum.
The term 'elevation' might also be used to refer to the height of something above or below a fixed reference point or datum.
What is end? - Noun
Noun - S: (n) end, terminal (either extremity of something that has length) "the end of the pier"; "she knotted the end of the thread"; "they rode to the end of the line"; "the terminals of the anterior arches of the fornix"
S: (n) end, terminal (either extremity of something that has length) "the end of the pier"; "she knotted the end of the thread"; "they rode to the end of the line"; "the terminals of the anterior arches of the fornix"
S: (n) end, ending (the point in time at which something ends) "the end of the year"; "the ending of warranty period"
S: (n) end, last (the final stage or concluding parts of an event or occurrence) "the end was exciting"; "I had to miss the last of the movie"
S: (n) goal, end (the state of affairs that a plan is intended to achieve and that (when achieved) terminates behavior intended to achieve it) "the ends justify the means"
S: (n) end (a final part or section) "we have given it at the end of the section since it involves the calculus"; "Start at the beginning and go on until you come to the end"
S: (n) end, destruction, death (a final state) "he came to a bad end"; "the so-called glorious experiment came to an inglorious end"
S: (n) end (the surface at either extremity of a three-dimensional object) "one end of the box was marked `This side up'"
S: (n) end ((football) the person who plays at one end of the line of scrimmage) "the end managed to hold onto the pass"
S: (n) end (a boundary marking the extremities of something) "the end of town"
S: (n) end (one of two places from which people are communicating to each other) "the phone rang at the other end"; "both ends wrote at the same time"
S: (n) end (the part you are expected to play) "he held up his end"
S: (n) conclusion, end, close, closing, ending (the last section of a communication) "in conclusion I want to say..."
S: (n) end, remainder, remnant, oddment (a piece of cloth that is left over after the rest has been used or sold)
S: (n) end ((American football) a position on the line of scrimmage) "no one wanted to play end"
Verb - S: (v) end, stop, finish, terminate, cease (have an end, in a temporal, spatial, or quantitative sense; either spatial or metaphorical) "the bronchioles terminate in a capillary bed"; "Your rights stop where you infringe upon the rights of other"; "My property ends by the bushes"; "The symphony ends in a pianissimo"
S: (v) end, stop, finish, terminate, cease (have an end, in a temporal, spatial, or quantitative sense; either spatial or metaphorical) "the bronchioles terminate in a capillary bed"; "Your rights stop where you infringe upon the rights of other"; "My property ends by the bushes"; "The symphony ends in a pianissimo"
S: (v) end, terminate (bring to an end or halt) "She ended their friendship when she found out that he had once been convicted of a crime"; "The attack on Poland terminated the relatively peaceful period after WW I"
S: (v) end, terminate (be the end of; be the last or concluding part of) "This sad scene ended the movie"
S: (v) end (put an end to) "The terrible news ended our hopes that he had survived"
Definition of end with - 1: to have (something) at the end
1: to have (something) at the end
2: to cause (something) to have (something) at the end
Views - Operation in Revit
Operation in Revit -
Posted on 19/09/2016 by Roberto Molinos -
Objectives - Use view types to quickly apply graphics properties and view templates to new views.
Use view types to quickly apply graphics properties and view templates to new views.
Learn how to navigate views, create dependent views, organize views in the Project Browser, create view lists and view types,
Modify view properties to change the view scale, detail level, visual style, orientation, and other properties of the view.
Difference between callouts and drafting views. - Understand visibility related to the different disciplines.
Understand visibility related to the different disciplines. - Prerequisites
Prerequisites - User has basic skills in BIM modelling with Revit Software, and understand the language used.
User has basic skills in BIM modelling with Revit Software, and understand the language used.
User has notions about the data structure in models.
User has basic notions of parametrization. - Description
Description - Views are how we are able to see our 3D model (and 2D details).
Views are how we are able to see our 3D model (and 2D details).
Revit has many View Types: -
Floor Plan Views - Reflected Ceiling Plan Views
Reflected Ceiling Plan Views - Structural Plans
Structural Plans - Area plans
Area plans - Elevation Views
Elevation Views - Section Views
Section Views - 3D Views
3D Views - Camera Views
Camera Views - Walkthroughs
Walkthroughs - Detail Views
Detail Views - Drafting Views
Drafting Views - Legends
Legends - Schedules
Schedules -
Procedure - View control
View control - Description
Description - Sometimes it is necessary to sort the view in groups and subgroups depending on users who use the views or the uses for which they are intended.
Sometimes it is necessary to sort the view in groups and subgroups depending on users who use the views or the uses for which they are intended.
The Project Browser can be set up as WIP (work in progress).
Views are organised into VIEWGROUP and VIEWSUBGROUP. They are two custom parameters* applied to views that organize the project browser. If a view group has been set up already, it will appear in the view group drop-down. Type new names is required.
Choose the option Project Parameter, it is not necessary to be Shared Parameter.
Type a name, in this case 'View Group'.
Choose the type of parameter, in this case "Text".
You choose the heading under which you want the new parameter appear in the Properties window, in this case "Text".
The parameter applies to instances and not by type, since we want to apply to each view in particular.
Finally it should be noted to what categories of objects we want to add this parameter, in this case "Views"
The fascia board is the one mounted at the point where the roof meets the outer walls of the house and is often called the ROOFLINE. However most people refer to it by the name of the main board that carries the gutter - the fascia or fascias.
Unfortunately, not many people are familiar with these terms, so we thought you might appreciate a few words of explanation.
The descriptions uPVC, PVCu and PVCue are often used to describe PVC fascias, soffits and bargeboards. You probably know what PVC means. The "u" stands for "unplasticised", meaning that it isn't a pliable PVC like some kids toys etc, and the "e" stands for "expanded". Expanded or foamed PVC produces a light, strong board that is thicker than an equivalent rigid PVC board.
The fascia board is the long, straight board that runs along the lower edge of the roof. The fascia is fixed directly to the lower ends of the roof trusses and usually does all the work of supporting the lower edge of the bottom row of tiles. The fascia board also carries all the guttering.
This is no mean feat, especially when it is raining hard. In a downpour the roof of a 3-bed semi could be washing several gallons of water per second into its gutters.
Finishes - Finishes are used in the final part of the construction or manufacturing process, forming the final surface of an element. They can protect the element they finish from impact, water, frost, corrosion, abrasion, and so on, and/or they can be decorative.
Finishes are used in the final part of the construction or manufacturing process, forming the final surface of an element. They can protect the element they finish from impact, water, frost, corrosion, abrasion, and so on, and/or they can be decorative.
Finishes commonly relate to internal surfaces, but they may also be applied to external elements. They can be applied wet or dry. Some elements are self-finished, that is the final surface is part of the material the element is formed from.
The application of finishes may involve the build up of more than one layer, which, whilst some of the layers will form the final exposed surface, they are nonetheless considered to be finishes. For example, an undercoat or primer might be applied to a wall before the final paint.
NBS categorise finishes as: -
Calcium sulfate based levelling screeds. - Cement based levelling / wearing screeds.
Cement based levelling / wearing screeds. - Decorative papers / fabrics.
Decorative papers / fabrics. - Edge fixed carpeting.
Edge fixed carpeting. - Insulation with rendered finish.
Insulation with rendered finish. - Intumescent coatings for fire protection of steelwork.
Intumescent coatings for fire protection of steelwork. - Mastic asphalt flooring/ floor underlays.
Mastic asphalt flooring/ floor underlays. - Metal lathing / anchored mesh reinforcement for plastered/ rendered coatings.
Metal lathing / anchored mesh reinforcement for plastered/ rendered coatings.
Painting / clear finishing. - Plastered / rendered / roughcast coatings.
Plastered / rendered / roughcast coatings. - Resin flooring.
Resin flooring. - Rubber / plastics / cork/ lino / carpet tiling / sheeting.
Rubber / plastics / cork/ lino / carpet tiling / sheeting.
Sprayed monolithic coatings. - Stone / concrete / quarry / ceramic tiling / mosaic.
Stone / concrete / quarry / ceramic tiling / mosaic.
Terrazzo tiling / in situ terrazzo. - Wood block / composition block / mosaic parquet flooring.
Wood block / composition block / mosaic parquet flooring.
However, this is some overlap in this categorisation with other building components, and some classifications might place some of these items within other categories. For example, plaster might be considered a lining rather than a finish stone might be considered part of the wall or floor construction, and so on.
Uniclass lists the following `decorative' coatings:
Aluminium paints. - Casein paints.
Casein paints. - Cement paints.
Cement paints. - Concrete finishing coats.
Concrete finishing coats. - Concrete flash coats.
Concrete flash coats. - Concrete floor dyes.
Concrete floor dyes. - Concrete floor paints.
Concrete floor paints. - Concrete stains.
Concrete stains. - Distemper.
Distemper. - High pigment water-borne paint.
High pigment water-borne paint. - Limewashes.
Limewashes. - Micaceous iron oxide paints.
Micaceous iron oxide paints. - Multi-colour coatings.
Multi-colour coatings. - Multi-colour finish spatter coatings.
Multi-colour finish spatter coatings. - Oil-bound distempers.
Oil-bound distempers. - Plant oil paints.
Plant oil paints. - Plastic texture paints.
Plastic texture paints. - Resin-based breathable masonry paints.
Resin-based breathable masonry paints. - Semi-transparent timber stains and dyes.
Semi-transparent timber stains and dyes. - Silicate-based masonry coatings.
Silicate-based masonry coatings. - Solvent-based finishing coats.
Solvent-based finishing coats. - Solvent-borne gloss finishes.
Solvent-borne gloss finishes. - Solvent-borne masonry paints.
Solvent-borne masonry paints. - Solvent-borne matt and flat finishes.
Solvent-borne matt and flat finishes. - Solvent-borne mid-sheen finishes.
Solvent-borne mid-sheen finishes. - Tallow lime washes.
Tallow lime washes. - Water-borne gloss finishes.
Water-borne gloss finishes. - Water-borne masonry paints.
Water-borne masonry paints. - Water-borne matt and flat finishes.
Water-borne matt and flat finishes. - Water-borne mid-sheen finishes.
Water-borne mid-sheen finishes. - The choice of finishes might be influenced by factors, such as:
The choice of finishes might be influenced by factors, such as:
Colour and appearance (matt, gloss, silk, and so on).
Texture. - Maintenance and cleaning requirements.
Maintenance and cleaning requirements. - Durability.
Durability. - Expected life.
Expected life. - Weather resistance.
Weather resistance. - Corrosion resistance.
Corrosion resistance. - Availability.
Availability. - Preparation required.
Preparation required. - Ease of application.
Ease of application. - Drying time.
Drying time. - Cost.
Cost. - Safety or environmental issues.
Safety or environmental issues. - Waste.
Waste. - NB The word 'finish' may also refer to the completion of an activity.
NB The word 'finish' may also refer to the completion of an activity.
Fire detection and alarm system FDAS - Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a fire alarm system as a: '...combination of components for giving an audible and/or other perceptible warning of fire.'
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a fire alarm system as a: '...combination of components for giving an audible and/or other perceptible warning of fire.'
Live investigations of false fire alarms, published by BRE in December 2015, suggests that a Fire Detection and Fire Alarm System is `...control equipment that utilises detectors, warning devices and other components to detect fires and provide warning.'
Most fire detection and alarm systems operate on the same basic principles. If a fire is detected, then an alarm is triggered. This warns building managers and occupants that there may be a fire and that evacuation may be necessary. Some systems include remote signalling equipment which can alert the fire brigade or a remote monitoring centre.
Fire can be detected by; heat detectors, flame detectors, smoke detectors, carbon monoxide detectors and multi sensor detectors, or an alarm can be triggered at manual call points. Alarms may consist of bells, sirens, horns, lights or a combination these. Two power supplies are required, generally a mains supply and batteries providing 24 hours back up.
It is important that a thorough assessment of need is undertaken before a fire detection and alarm system is designed or purchased.
In the UK, fire alarm systems are categorised as:
L, (L1 to L5): automatic systems intended for the protection of life.
M: manual systems, fitted with sounders and call points.
P, (P1 and P2): automatic systems intended for the protection of property.
Fire detection and alarm systems can be divided into a number of general types:
Conventional systems. - Addressable systems.
Addressable systems. - Analogue addressable systems.
Analogue addressable systems. - Wireless systems.
Wireless systems. - Self-contained units.
Self-contained units. - Conventional systems generally consist of a series of detectors and call points wired to a control panel which drives the detectors and a minimum of two sounder circuits, includes LED indicators and allows de-activation and resetting. Typically, separate circuits will be provided for each fire 'zone' (usually a floor of a building or a fire compartment). This separation into zones means that the approximate location of the fire is known and so the appropriate response can be instigated. It also allows for easier diagnosis of faults.
Conventional systems generally consist of a series of detectors and call points wired to a control panel which drives the detectors and a minimum of two sounder circuits, includes LED indicators and allows de-activation and resetting. Typically, separate circuits will be provided for each fire 'zone' (usually a floor of a building or a fire compartment). This separation into zones means that the approximate location of the fire is known and so the appropriate response can be instigated. It also allows for easier diagnosis of faults.
Addressable systems are similar to conventional systems, but the central control panel can identify exactly which detector or call point triggered the alarm (rather than just a zone), or whether communication has been lost with a detector. In this system the circuit is wired in a loop, with a number of detectors or call points on each loop. The loop can be powered from both ends, so that it continues to function even if there is a break in the loop (separate loops may still be provided for each zone).
The control panel can be programmed to show specific information, or trigger specific responses for different detectors within the system. Addressable systems are generally used for larger or more complex installations because of the benefits of more accurate detection, and so fault finding, and the reduced wiring requirement.
Analogue addressable systems, or intelligent systems can include an analytical capability in each detector which can assess local parameters to determine whether there is a fire, a fault or a maintenance requirement. This can be useful in preventing the occurrence of false alarms. A pre-alarm warning may be indicated if a detector is approaching a trigger condition.
Wireless fire alarm systems connect detectors and call-points to the control panel using wireless signals.
Self-contained fire alarm units are generally only suitable for small installations. They consist of a single unit, including break glass contact, sounder, power supply, battery and charger.
It is important that fire alarm and detection systems are regularly inspected, serviced and tested, and fire drills may be held to ensure occupants are familiar with fire and evacuation procedures.
NB: The 2014 BRE briefing paper, The causes of false fire alarms in buildings, found that; 'False alarms generated from remotely monitored fire detection and fire alarm systems cost businesses and Fire and Rescue Service (FRS) authorities an estimated Pound1bn per year in the UK. In the period 2011-2012 a total of 584,500 fire and false alarms were reported in Britain, 53.4% of these were not fires and therefore considered false alarms. This is a considerable drain on FRS authorities as well as causing business disruptions leading to a loss of productivity and reducing the confidence of the general public.'
The paper proposed that education could contribute significantly to reducing false alarms and that the increased use of multi-sensor detectors is a cost effective way of averting false alarms from common causes such as cooking fumes and steam.
In relation to the built environment, the term `function' refers to the purpose of a building or structure. It can also relate to the proper operation, process or performance of something and how it works, such as plant, tools, lift, building services.
In architecture, functionalism (or `form follows function') is the principle that rather than buildings being designed in accordance with past precedents or stylistic trends (aesthetics), the underlying purpose of the building should determine its form.
Buildings have a wide range of different functions, for example, a house is to be lived in, an office serves as a place of work for business activities, a shopping centre is for consumers to access retail outlets, a school is for pupils and teachers to undertake education, and so on.
Buildings may have a range of different functions (for example, a factory may include offices, a restaurant, assembly lines and so on) and some functions may conflict with one another, for example, access vs security, views vs privacy and so on.
Products, materials, components and systems, can be assessed in terms of their functionality, that is, the suitability and capability with which they serve a particular purpose or practicality for which they were intended.
Adjective: - parallel to the plane of the horizon; at right angles to the vertical.
parallel to the plane of the horizon; at right angles to the vertical.
being at or involving the same level of a hierarchy.
Noun: - a horizontal line, plane, etc.
a horizontal line, plane, etc. -
Installation -
In general, installation is the act of installing something in a fixed, semi-fixed or temporary location. It can also refer to a complete unit which has been installed.
In terms of construction, it often refers to machinery, plant, apparatus, etc., being placed in position or connected for use. Often this can refer to a system or unit with accompanying assemblies, accessories, parts, and so on. It can also include connection to the services which are required to enable the installation to operate.
Installation drawings are developed from co-ordinated detail drawings and present the information needed by trades to install part of the works. This may be particularly important for complex installations such as plant rooms, data centres, ventilation systems, underfloor heating, and so on.
Setting the bar. A new competence regime for building a safer future. The Final Report of the Competence Steering Group for Building a Safer Future, published in October 2020, defines an installer as: `An operative or organisation working, with the appropriate competencies, to place a specific product or system on-site.'
Introduction - There are various definitions of the term `labour'.
There are various definitions of the term `labour'.
Construction - In the construction industry, labor is the term usually given to unskilled, manual workers on a site, i.e what is normally termed `manual labour' or `site labour'. It may do a variety of jobs including, digging, cleaning, catering, carrying and lifting. Typically, such workers have little training or qualifications and may be employees of a contractor or sub-contractor, or temporary workers hired for part or all of the project. The term labour does not include consultants or skilled tradespeople (trades).
In the construction industry, labor is the term usually given to unskilled, manual workers on a site, i.e what is normally termed `manual labour' or `site labour'. It may do a variety of jobs including, digging, cleaning, catering, carrying and lifting. Typically, such workers have little training or qualifications and may be employees of a contractor or sub-contractor, or temporary workers hired for part or all of the project. The term labour does not include consultants or skilled tradespeople (trades).
In the UK in recent years, much manual labour has come from countries such as Poland and Eastern Europe, particularly Romania and Bulgaria. Poland in particular has also supplied many skilled plumbers, electricians, carpenters and so on.
Economics - In the world of economics, `labour' is one of the three `factors of production', along with land and capital. Historically, the three factors have been required in combination to create a business or enterprise. However, the advent of the internet and e-business has obviated the need for land in some instances, e.g a business that only exists in cyberspace and therefore has no requirement for premises.
In the world of economics, `labour' is one of the three `factors of production', along with land and capital. Historically, the three factors have been required in combination to create a business or enterprise. However, the advent of the internet and e-business has obviated the need for land in some instances, e.g a business that only exists in cyberspace and therefore has no requirement for premises.
Politics - `Labour' is the name of a British political party that aims to support the interests of the workers and the lower-paid sections of society. Traditionally a party of the centre-left, it was founded in 1900 and grew out of the trade union movement. Since the 1920s, it has been the main rival to the Conservative Party. Ever since, the two entities have dominated British politics, alternating in power in what is called a `two-party' system.
`Labour' is the name of a British political party that aims to support the interests of the workers and the lower-paid sections of society. Traditionally a party of the centre-left, it was founded in 1900 and grew out of the trade union movement. Since the 1920s, it has been the main rival to the Conservative Party. Ever since, the two entities have dominated British politics, alternating in power in what is called a `two-party' system.
The term `labour' may also be applied to similar left-leaning political parties around the world although they may not have `labour' in their name but may be called something else, e.g the workers party or the socialist party. But generally, they will still be the party of labour.
Verb - When used as a verb, to `labour' can mean to toil earnestly, or work hard or persistently at some task.
When used as a verb, to `labour' can mean to toil earnestly, or work hard or persistently at some task.
The term `lighting' refers to equipment, the primary purpose of which, is to produce light. This is typically some form of lamp, but lighting can also refer to the use of natural light to provide illumination.
Light is the electromagnetic radiation that exists within a certain portion of the electromagnetic spectrum. In terms of 'visible light', i.e. that which enables the sense of sight, it is the part of the spectrum that can be detected and seen by the eye.
The level of light on a surface is described as `Illuminance' and is measured in lux (lx), where one lux is equal to one lumen per square metre (lm/m) and a lumen is the SI unit (International System) of luminous flux, describing the quantity of light emitted by a lamp or received at a surface.
In relation to external lighting, Urban Design Guidelines for Victoria, published by The State of Victoria Department of Environment, Land, Water and Planning in 2017 suggests that: `Lighting performs a number of functions, from supporting way-finding, orientation and safe movement at night to providing a decorative effect for building facades, landmarks and paths. Lighting systems can be large- scale and utilitarian, or small and ornamental. They may use overhead lamps, bollards, up-lights, bulkhead or veranda lighting, feature and facade illumination. Shop display lighting can also contribute to overall public realm lighting levels. Lighting is critical to creating a public realm that is safe and inviting for users.'
Together, the Upper Limit and Limit Offset parameters define the upper boundary of the room.
Note: If room-bounding elements intersect the upper limit offset, those elements form the upper boundary instead. (See About Ceilings and Floors in Room Volume Computations.)
For example, suppose a room starts at Level 1. To indicate that it should extend upward 4000 mm above Level 2, specify an Upper Limit of Level 2 and a Limit Offset of 4000 mm. By default, the Limit Offset is the distance between levels (10' or 4000 mm).
Line weight is the visual lightness, darkness, or heaviness of a line within a drawing. In any architectural drawing, from a sketch to a construction drawing, the interplay of different relative line weights is used to communicate depth, importance, and proximity.
Column location mark: - The coordinate location of a vertical column on the project grid.
The coordinate location of a vertical column on the project grid.
A manufacturer is an organisation or business that produces goods to sell them to a customer. Manufacturers transform raw materials, components, assemblies, and so on, into finished products, often involving processes organised into a production line.
Manufactured products are commonly made on a large scale before being distributed to customers, wholesalers, distributors, retailers and so on.
Manufacturing operations tend to utilise one of the following types of production:
Make-to-stock (MTS): Goods are produced by predicting the market and producing regardless of orders being received. There is the risk that producing too much will result in needing to sell any surplus at a loss, whereas producing too little will result in not selling enough to maximise profit or even cover operating costs.
Make-to-order (MTO): Goods are produced when orders are received, making it easier to control inventory. However, this can result in longer waiting times for clients, and a steady stream of orders is required otherwise production will stop.
Make-to-assemble (MTA): Component parts are produced in anticipation of orders for assembly. This means the manufacturer is ready to fulfil orders, but it can result in a backlog of parts that are waiting to be used if demand is slower than anticipated.
Testing and certification can be used to verify quality.
Manufacturers must adhere to certain standards and regulations when producing their goods. For example, the Eco-Design for Energy-Related Products Regulations 2010 requires manufacturers to achieve minimum standards for the amount of energy regulated products consume. A declaration of conformity must be drawn up by the manufacturer or importer and the CE mark applied.
In the construction industry, manufacturers are often referred to as suppliers. For more information see: Suppliers.
Designing Buildings Wiki has a range of articles relating to manufacturing, including:
3D printing in construction. - Advanced manufacturing.
Advanced manufacturing. - British Standards Institution BSI.
British Standards Institution BSI. - Buildability in construction.
Buildability in construction. - Building information modelling and its effect on computer aided manufacture in the UK construction industry.
Building information modelling and its effect on computer aided manufacture in the UK construction industry.
Circular economy. - Computer aided manufacturing CAM.
Computer aided manufacturing CAM. - Demand for Off-Site Construction Continues to Increase in the UK's Manufacturing Sector.
Demand for Off-Site Construction Continues to Increase in the UK's Manufacturing Sector.
How Computer Aided Manufacturing is Changing the World.
Intelligent building management systems IBMS. - Intermediate product.
Intermediate product. - Kitemark.
Kitemark. - Lean construction.
Lean construction. - Life cycle assessment.
Life cycle assessment. - Manufacturing better buildings.
Manufacturing better buildings. - Mean lean green.
Mean lean green. - Modern methods of construction.
Modern methods of construction. - Offsite manufacturing.
Offsite manufacturing. - Offsite manufacturing and standardised design.
Offsite manufacturing and standardised design. - Prefabrication.
Prefabrication. - Product transparency declaration.
Product transparency declaration. - Purchase orders.
Purchase orders. - Quality control for construction works.
Quality control for construction works. - Virtual reality and manufacturing.
Virtual reality and manufacturing. -
Maximum Ridge Height - The maximum height of the top of the roof above the base level of the building. You can set a maximum allowable ridge height using the Max Ridge Height tool. This is a read-only value. This property is enabled only when creating a roof by footprint.
The maximum height of the top of the roof above the base level of the building. You can set a maximum allowable ridge height using the Max Ridge Height tool. This is a read-only value. This property is enabled only when creating a roof by footprint.
Projected area is the two dimensional area measurement of a three-dimensional object by projecting its shape on to an arbitrary plane. This is often used in mechanical engineering and architectural engineering related fields, specifically hardness testing, axial stress, wind pressures, and terminal velocity.
In very general terms, a model is a representation, often three-dimensional, of a structure system or procedure. It can represent something that already exists, or may be a model that it is intended will be adopted or followed.
A building, such as an architectural model is a type of model (often to scale) built to develop or represent aspects of a design or to communicate design ideas. Historically, such models have been physical representations, made from materials such as paper, cardboard, timber, and so on. These can be used to help explain proposals to clients, planning officers, members of the public and other stakeholders, or they can be used as tools to help designers explore complicated three-dimensional aspects of a design.
More recently, models have been created digitally using software such as computer aided design (CAD) and building information modelling (BIM). 3D printing of digital models is used for a physical representation of digital design files.
Model-based design is a process that involves creating digital representations systems to help with design development and decision-making. It allows rapid analysis and comparison of design alternatives, co-ordination of and collaboration between team members, clear communication and visualisation of information, easy alteration, clash avoidance, and so on.
In the early stages of a project, a digital model might simply include existing information, such as 3D context models, site surveys, condition surveys, information about existing utilities and so on. During the design stages it becomes more detailed, and ultimately, as contractors take over development of the model from designers, it may become a virtual construction model (VCM), containing information allowing all the objects in the model to be manufactured, installed or constructed.
Parametric modelling (or parametric design) is the creation of a digital model based on a series of pre-programmed rules or algorithms known as 'parameters'. That is, the model, or elements of it are generated automatically by internal logic arguments rather than by being manually manipulated. For example, a rule might be created to ensure that walls must start at floor level and reach the underside of the ceiling. Then if the floor to ceiling height is changed, the walls will automatically adjust to suit.
Digital models are generally made up of a number of different component models that may be produced by different consultants, contractors or suppliers.
Designing Buildings Wiki has a range of articles relating to models, including:
3D animation for building insurance risk analysis. - As-built or as-constructed building information model.
As-built or as-constructed building information model. - Asset information model AIM.
Asset information model AIM. - ASTM International architectural model program standard E3223.
ASTM International architectural model program standard E3223. - Building Information Modelling.
Building Information Modelling. - Business model.
Business model. - Data-centric business model.
Data-centric business model. - Design intent model.
Design intent model. - Enterprise model for infrastructure.
Enterprise model for infrastructure. - Model-based design.
Model-based design. - Parametric modelling.
Parametric modelling. - PAS 182 Smart city data concept model.
PAS 182 Smart city data concept model. - Project information model PIM.
Project information model PIM. - Rapid prototyping.
Rapid prototyping. - Simplified Building Energy Model SBEM.
Simplified Building Energy Model SBEM. - Virtual construction model.
Virtual construction model. - Visualisation.
Visualisation. -
monolithic stair: - Specifies that the stairs are to be made of one material.
Specifies that the stairs are to be made of one material.
Landing overlap: - Enabled when stairs are set to monolithic. When a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped. If it is stepped, this parameter controls the distance between the riser face and the vertical face of the corresponding step on the underside.
Enabled when stairs are set to monolithic. When a monolithic stair has a winder, the bottom of the stair can be a smooth shape or stepped. If it is stepped, this parameter controls the distance between the riser face and the vertical face of the corresponding step on the underside.
Classification, an introduction describes classification as, `what things are called, and how those names are arranged and structured', or `the act or process of dividing things into groups according to their type.'
In the construction industry, classification is used in:
Specifications. - Production information.
Production information. - Libraries.
Libraries. - Drawings.
Drawings. - Schedules of rates / quantities.
Schedules of rates / quantities. - Information management systems.
Information management systems. - Operation and maintenance information.
Operation and maintenance information. - The OmniClass Construction Classification System, also known as OmniClass(TM) or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
The OmniClass Construction Classification System, also known as OmniClass(TM) or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
It covers the full facility lifecycle from conception to demolition or reuse, and all types of construction in the built environment. It is useful for Building Information Modelling (BIM), organising reports and object libraries.
Similar to Uniclass, OmniClass is derived from internationally-accepted standards developed by the International Organisation for Standardisation (ISO) and the International Construction Information Society (ICIS) and has been developed from the early-1990s to the present.
OmniClass comprises 15 tables, some of which focus on buildings and landscapes, and some of which also serve civil and/or process engineering. Each table can be used independently to classify a particular type of information, or entries on it can be combined with entries on other tables to classify more complex subjects.
The tables are as follows: -
Construction Entities by Function - Table 11. - Construction Entities by Form - Table 12.
Construction Entities by Form - Table 12. - Spaces by Function - Table 13.
Spaces by Function - Table 13. - Spaces by Form - Table 14.
Spaces by Form - Table 14. - Elements (includes Designed Elements) - Table 21.
Elements (includes Designed Elements) - Table 21.
Work Results - Table 22. - Products - Table 23.
Products - Table 23. - Phases - Table 31.
Phases - Table 31. - Services - Table 32.
Services - Table 32. - Disciplines - Table 33.
Disciplines - Table 33. - Organisational Roles - Table 34.
Organisational Roles - Table 34. - Tools - Table 35.
Tools - Table 35. - Information - Table 36.
Information - Table 36. - Materials - Table 41.
Materials - Table 41. - Properties - Table 49.
Properties - Table 49. - OmniClass incorporates other extant systems currently in use, such as; MasterFormat(TM) for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
OmniClass incorporates other extant systems currently in use, such as; MasterFormat(TM) for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
Orientation: - Angled movement on a horizontal plane of turning part of the crane.
Angled movement on a horizontal plane of turning part of the crane.
Projects, by definition, have a beginning and an end. They also have defined phases between the project kickoff and project closeout. A phase represents a grouping of similar activities that has a very loosely defined beginning and end. Phases are also typically sequential, where the prior phase is essentially complete before the beginning of the next phase. Phases do not have clear-cut end dates and some activities in an early phase of the project will continue into the later phases. This is in contrast to project beginning and ending dates and milestone dates, which do have clearly defined dates with the expectation that these dates will be met.
The production in construction index is a business-cycle indicator which measures the monthly changes in production of buildings (residential and non-residential) and of civil engineering (roads, railways, bridges, tunnels, utility projects).
Conceptually the index shows changes in the volume of construction, i.e. the price adjusted change in the value added to the economy by this sector. As this statistical concept is not directly measurable, the indicator is approximated by several other measures.
Mathematically the index is calculated as a Laspeyres volume index.
Net construction output can be calculated using different data sources:
gross production data from which input received from other sectors is substracted;
turnover; - input of labour and material.
input of labour and material. -
A rafter is a structural component that is used as part of a roof construction. Typically, it runs from the ridge or hip of the roof to the wall plate of the external wall. Rafters are generally laid in series, side by side, providing a base to support roof decks, roof coverings and so on.
Rafters are typically made of timber or steel and can be concealed within the roof structure, or can be left exposed to the spaces below. The may have battens laid on top of and perpendicular to them, to fix the roof covering to.
Rafters can be used as a key component of various types of roof design. The couple roof comprises two rafters leaning against each other, tied where they meet at the top. The rafters sit on a wall plate which is an efficient means of spreading the load exerted by the roof structure down through the walls without creating pressure points where each rafter meets the wall.
A closed couple roof adds ceiling joists running horizontally between the rafter feet, to support a ceiling and to make the structure much more rigid.
In order to increase potential roof spans without compromising wall stability, increasing rafter sizes or attracting extra costs, purlins were introduced. These run perpendicular to rafters, providing additional stiffness. By installing a purlin into the roof structure, rafters no longer needed to be as thick and heavy, allowing larger potential spans.
In modern house construction, the most common form of rafter is known as the fink or 'w' trussed rafter. This consists of a rafter incorporating tension and compression members in the shape of a W. This is capable of spans up to 12 m and can be designed to accommodate many different pitch angles.
Rebar, also known as reinforcement steel and reinforcing steel, is a steel bar or mesh of steel wires used in reinforced concrete and masonry structures to strengthen and hold the concrete in tension. To improve the quality of the bond with the concrete, the surface of rebar is often patterned.
Rebar is necessary to compensate for the fact that whilst concrete is strong in compression, it is relatively weak in tension. By casting rebar into concrete, it is able to carry tensile loads and so increase overall strength.
Different uses of rebar include: -
Primary reinforcement: Used to provide resistance to support design loads.
Secondary reinforcement: Used for durability and aesthetic purposes by providing localised resistance to limit cracking and temperature-induced stresses.
Provide resistance to concentrated loads, spreading it through a wider area.
Assist other steel bars in accommodating their loads by holding them in the correct position.
External steel tie bars to constrain and reinforce masonry structures, sometimes as a means of building conservation.
Reinforced masonry: Some masonry blocks and bricks include voids to accommodate rebar to carry tensile loads. The rebar is secured in place using grout.
Manufacturing - Standards for the specification of rebar are set out in: BS 4449: 2005 Steel for the reinforcement of concrete. Weldable reinforcing steel. Bar, coil and decoiled product. Specification
Standards for the specification of rebar are set out in: BS 4449: 2005 Steel for the reinforcement of concrete. Weldable reinforcing steel. Bar, coil and decoiled product. Specification
Rebar is commonly manufactured using mild or high yield steel of grade 250 or 250 N/mm2 characteristic tensile strength. The constituents of both of these grades are around 99% iron, along with manganese, carbon, sulphur and phosphorous. The quality and grade of steel is dependent on the proportion of carbon. Mild cold-worked steel contains around 0.25% carbon, whereas high yield hot-rolled steel contains around 0.40%.
Bars can be manufactured in various forms: -
Round. - Square-twisted.
Square-twisted. - Ribbed.
Ribbed. - Stretched, twisted and ribbed.
Stretched, twisted and ribbed. - Ribbed and twisted.
Ribbed and twisted. - Steel reinforcement mesh or fabric can be produced in different formats following BS 4483: Steel fabric for the reinforcement of concrete. Specification.
Steel reinforcement mesh or fabric can be produced in different formats following BS 4483: Steel fabric for the reinforcement of concrete. Specification.
The standard sheet size is 4.8 m long x 2.4 m wide. It is formed by interweaving or electronically-welding the wires so that it will withstand normal handling. It can be produced in different ways for different applications:
Square mesh: Mesh size of 200 mm x 200 mm, weight range of 1.54-6.16 kg/sq. m. Typically used for floor slabs.
Rectangular mesh: Mesh size of 200 mm x 100 mm, weight range of 3.05-10.9 kg/sq. m. Typically used for floor slabs.
Long mesh: Mesh size of 100 mm x 400 mm, weight range of 2.61-6.72 kg/sq. m. Typically used for road and pavement construction.
Wrapping mesh: Mesh size of 100 mm x 100 mm. Typically used in suspended or ground supported slabs.
Placing rebar -
Rebar cages are either pre-fabricated or constructed on site using hydraulic benders and shears. Site labourers known as steel fixers place the rebar and ensure adequate concrete cover and embedment. Rebar cages are connected either by spot welding, tying steel wire or with mechanical connections. Mechanical connections, also known as `couplers' or `splices', are an effective means of reducing rebar congestion in highly-reinforced areas for cast-in-place concrete construction.
Rectangular stirrups are placed at regular intervals on the outer part along a column or beam to prevent shear failure.
For safety purposes while being stored on site, protruding ends of rebar should be bent over or guarded by using coloured plastic `mushroom caps'.
Although rebar has ribs that bind it mechanically to the concrete, high stresses can still pull the rebar out of the concrete, which may lead to structural instability and ultimately failure. To prevent this, rebar must be deeply embedded into adjacent structural members (40-60 times the diameter), which increases the friction locking the bar into place. Alternatively, rebar can be bent and hooked at the ends to lock it around the concrete and other rebar sections, which makes use of the concrete's high compressive strength.
Steel rebar can also be susceptible to corrosion if insufficient cover is provided which can cause the concrete to spall away from the steel, and render it less efficient in terms of fire resistance. As a general rule, the minimum cover should not be less than the maximum size of the aggregate in the concrete, or the largest reinforcement bar size (whichever is largest).
NB In November 2019, The British Association of Reinforcement (BAR) issued a warning to clients and contractors to check prefabricated reinforcement was welded by workers certified to do the job. CARES is the Certification Authority for Reinforcing Steels.
Rooms and room tags are separate but related Revit Architecture components. Rooms are model elements in Revit Architecture, like walls and doors. Room tags are annotation elements that can be added and displayed in plan views and section views. Room tags can display values for related parameters, such as room number, room name, computed area, and volume.
A sash is a glazed part of a window or door assembly that opens for purposes of ventilation, viewing out, etc.
In a casement window, the sash is the hinged part of the window (within the frame) that opens outwards or inwards for ventilation. It is the part which holds the glass in position in a secondary frame within the main window frame.
In a traditional sliding sash window, the sash is the glazed part which slides vertically to allow ventilation, views out etc, and holds the glass in place. Such windows usually have two sliding sashes.
For more information see: Window. -
The term sash can also be applied to doors which incorporate glass, i.e the hinged part of a door assembly which opens for entry and exit and which is either fully or partly glazed. When a door is not glazed, the opening part is usually called the `door leaf'.
In very general terms 'scale' refers to an item's size in relationship to something else. For example, the components of a building may be designed so they are at a human scale, ie they are comfortable to use, are functional and anthropometric, or manufacturing can be carried out at scale, rather than for one-offs..
Typically, architecture deals with different types of scale:
Human scale: The human interaction with environments based on physical dimensions, capabilities and limits. Buildings can be designed with greater or lesser adherence to the concepts of human scale depending on the concept and purpose of the building.
Intimate scale: This is a smaller, more personal scale.
Monumental scale: This is much larger than human scale and is intended to be impressive, e.g. public buildings, memorials, religious buildings, and so on.
Proportion: This refers to the relative size of parts of a whole, the relationship between two things of different size.
The term scale is also used to describe the relationship between a depiction of a building, object, area of land etc compared to its actual size. Depictions are typically drawings or physical models. Drawing accurately to scale, and being able to shift between scales, is a fundamental skill of architectural drawing and spatial design.
Scale drawings are used to illustrate items that it is not useful or convenient to draw at their actual size. In the construction industry, a range of scales are generally used depending on the nature of the drawing. For example:
A location plan at 1:1000. - A site plan at 1:200.
A site plan at 1:200. - A floor plan at 1:100.
A floor plan at 1:100. - A room plan at 1:50.
A room plan at 1:50. - A component drawing at 1:5.
A component drawing at 1:5. - An assembly drawing at 1:1.
An assembly drawing at 1:1. - The first number refers to the size of the depiction (such as a drawing or model), and the second number refers to the relative size of the actual item being depicted. So that on a scale of 1:5, the actual item is 5 times bigger than the depiction, whereas on a scale of 5:1, the item is 5 times smaller.
The first number refers to the size of the depiction (such as a drawing or model), and the second number refers to the relative size of the actual item being depicted. So that on a scale of 1:5, the actual item is 5 times bigger than the depiction, whereas on a scale of 5:1, the item is 5 times smaller.
By referring to a drawing or model as being `to scale', it means that every element of it is represented to the same proportion, i.e. with the same relationships as the physical thing, but it is reduced or increased in size by a certain amount.
Digital depictions such as building information models (BIM) of computer aided design (CAD) drawings are generally not considered to be at a specific scale, that is, whist the relative proportions are correct, the user can zoom in or out and print drawings at whatever scale is required.
Other definitions - The Town and Country Planning (Development Management Procedure) (England) Order 2015 defines scale as: `the height, width and length of each building proposed within the development in relation to its surroundings.'
The Town and Country Planning (Development Management Procedure) (England) Order 2015 defines scale as: `the height, width and length of each building proposed within the development in relation to its surroundings.'
Urban Design Guidelines for Victoria, published by the State of Victoria (Australia) in 2016, defines scale as: `The size of a building in relation to its surroundings, or the size of parts or details of the building, particularly in relation to the scale of a person. Scale refers to the apparent size, not the actual size.'
Seated connection: - Connections that join structural steel members with metal connectors, such as an angle upon which one member, such as a beam, rests.
Connections that join structural steel members with metal connectors, such as an angle upon which one member, such as a beam, rests.
The height between the base of the window and floor level is known as sill height. In general, to ensure privacy, the sill height in bathrooms and bedrooms is kept equal to or greater than 1100 mm(3.5 feet) from the floor level.
What Is Ground Level? - The term `ground level`, or `ground floor`, is used to refer to the level of a building that is at ground / street level. The term `storey' tends to refer to all levels of a building above the ground level. It can also refer to the level of ground that has not be built on.
The term `ground level`, or `ground floor`, is used to refer to the level of a building that is at ground / street level. The term `storey' tends to refer to all levels of a building above the ground level. It can also refer to the level of ground that has not be built on.
Lintel and Sill - A lintel or lintol is a structural horizontal block that spans the space or opening between two vertical supports. In the case of windows, the bottom span is instead referred to as a sill, but, unlike a lintel, does not serve to bear a load to ensure the integrity of the wall.
A lintel or lintol is a structural horizontal block that spans the space or opening between two vertical supports. In the case of windows, the bottom span is instead referred to as a sill, but, unlike a lintel, does not serve to bear a load to ensure the integrity of the wall.
What is Plinth Level? - A-Level where the substructure ends and the superstructure starts is known as the plinth level. The plinth is a part of the superstructure located between the ground level and the finished floor level. The plinth helps in transferring the superstructure's load to the foundation.
A-Level where the substructure ends and the superstructure starts is known as the plinth level. The plinth is a part of the superstructure located between the ground level and the finished floor level. The plinth helps in transferring the superstructure's load to the foundation.
Sill Level Height - Sill level height varies from room to room and depends on the room type. For bedrooms generally, a height 1100 mm is adopted due to privacy while in the drawing-room, commonly height 600-650 is provided. The minimum required height of the sill level should be 44 inches.
Sill level height varies from room to room and depends on the room type. For bedrooms generally, a height 1100 mm is adopted due to privacy while in the drawing-room, commonly height 600-650 is provided. The minimum required height of the sill level should be 44 inches.
What Is Sill Level? - It is the height up to the window base, measuring from the building's floor level to the window base upward. Or. A level between the building's window base and floor level above ground level is known as the sill level. The concrete bed or mortar bed is placed at the window base level.
It is the height up to the window base, measuring from the building's floor level to the window base upward. Or. A level between the building's window base and floor level above ground level is known as the sill level. The concrete bed or mortar bed is placed at the window base level.
Floor Finishing Level - Finished floor level (FFL) refers to the uppermost surface of a floor once construction has been completed but before any finishes have been applied. Floor levels and other vertical dimensions are usually expressed in meters to three decimal places, e.g FFL 16,550.
Finished floor level (FFL) refers to the uppermost surface of a floor once construction has been completed but before any finishes have been applied. Floor levels and other vertical dimensions are usually expressed in meters to three decimal places, e.g FFL 16,550.
Lintel Level of a House - The lintel level is the height or vertical measurement from the bottom edge to the top horizontal component of a window or door, the lintel is provided above the doors and windows to transfer the upward wall load to the surrounding wall.
The lintel level is the height or vertical measurement from the bottom edge to the top horizontal component of a window or door, the lintel is provided above the doors and windows to transfer the upward wall load to the surrounding wall.
Plinth in Building - A plinth level forms the foundation of a house. It is a rectangular block of stone on which a column and pillar of a building stands. It is a wall between the ground level and the ground floor level. The main function of a plinth in construction is to distribute the load of the columns over the foundation evenly.
A plinth level forms the foundation of a house. It is a rectangular block of stone on which a column and pillar of a building stands. It is a wall between the ground level and the ground floor level. The main function of a plinth in construction is to distribute the load of the columns over the foundation evenly.
Span - Introduction
Introduction - In structural engineering and architecture, `span' is the term given to the length of a structural component - eg beam, floor, roof or floor truss - that extends (or `spans') between two supports. Thus, a beam may be supported at either end, in which case it is said to span between the two points, and a floor may span between two (or three or even four) continuous supports.
In structural engineering and architecture, `span' is the term given to the length of a structural component - eg beam, floor, roof or floor truss - that extends (or `spans') between two supports. Thus, a beam may be supported at either end, in which case it is said to span between the two points, and a floor may span between two (or three or even four) continuous supports.
A general engineering principle is the longer the span, the deeper the structural component will have to be to safely support its self-weight and whatever it must carry, eg a floor.
Span-to-depth (STD) ratio - Span-to-depth ratio (or span/depth ratio, also known as slenderness ratio L/h) is the ratio of the span length divided by the depth (or vertical height) of a component. It is an important parameter as it can affect structural behaviour, construction costs and aesthetics.
Span-to-depth ratio (or span/depth ratio, also known as slenderness ratio L/h) is the ratio of the span length divided by the depth (or vertical height) of a component. It is an important parameter as it can affect structural behaviour, construction costs and aesthetics.
A 250mm-deep beam that spans 4m has a span/depth ratio of 16. If the span/depth ratio is less than two, the beam is considered to be `deep'. Eurocode 2 gives span/depth rules for designing reinforced concrete beams and slabs.
More dramatic span/depth ratios can be provided by space frames: a rectangular space frame may have a span/depth ratio of up to 40, while this can be as high as 60 for a skew space frame.
Span/depth ratios are useful in limiting the deflection of a member under service loads. Damage may result if limits are exceeded, eg cracking of plaster, partitions and supporting brickwork. If limits are exceeded wildly, catastrophic structural failure accompanied by potential loss of life may result.
In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge's span to its girder depth. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.
Stairs nosing - Approved Document K - Protection from falling, collision and impact defines the `nosing' of stairs as `the leading edge of a stair tread'.
Approved Document K - Protection from falling, collision and impact defines the `nosing' of stairs as `the leading edge of a stair tread'.
The pitch of stairs is the angle of inclination between the horizontal and a line connecting the nosings.
For buildings other than dwellings, step nosings should be made visually apparent by using a contrasting material on both the tread and the riser a minimum of 55 mm wide. If possible, step nosings that protrude over the tread below should be avoided. If the nosing does protrude, it should be by no more than 25 mm.
For common access areas in buildings that contain flats step nosings should be visually apparent, using a material that contrasts visually, 50 - 65 mm wide on the tread and 30 - 55 mm on the riser. A suitable tread nosing profile, should be used.
Approved document M, Volume 1: Dwellings (2015 edition incorporating 2016 amendments), defines a `suitable tread nosing'as; `Nosings that conform with one of the options shown in diagram 1.2 of approved document K'
On an alternating tread stairs alternating steps should be uniform with parallel nosings.
A pitch line is a line that connects the nosing of the treads of a stair.
Stairs riser - Part K of the building regulations requires that the rise, going, handrails, headroom, length and width of any stairs, ladders and ramps between levels are appropriate to afford reasonable safety to people gaining access to and moving about buildings.
Part K of the building regulations requires that the rise, going, handrails, headroom, length and width of any stairs, ladders and ramps between levels are appropriate to afford reasonable safety to people gaining access to and moving about buildings.
Approved Document K - Protection from falling, collision and impact describes provisions that would satisfy this requirement. It defines the `rise' of stairs as the height between consecutive treads, or for ramps, the vertical distance between each end of the ramp flight.
All buildings should have level treads on steps, with the rise and going of each step consistent throughout a flight of steps. If stairs have more than 36 risers in consecutive flights there should be a minimum of one change of direction between flights.
Buildings other than dwellings should not have single steps. For flights between landings the maximum number of risers should be 16 risers for utility stairs and for general access stairs, 12 risers, but exceptionally no more than 16 in small premises where the plan area is restricted.
In buildings other than dwellings, risers should not be open, in order to avoid feet or walking aids being caught underneath the tread during ascent, possibly causing a fall or giving occupants a feeling of insecurity. In dwellings, steps may have open risers if treads overlap by a minimum of 16 mm and steps are constructed so that a 100 mm diameter sphere cannot pass through the open risers.
In buildings other than dwellings, step nosings should be made apparent using a visually contrasting material, a minimum of 55 mm wide, on both the tread and the riser. For common access areas in buildings that contain flats, risers should not be open and step nosings should be visually apparent, using a material that contrasts visually, 50 - 65 mm wide on the tread and 30 - 55 mm on the riser.
Where there are stepped gangways in assembly buildings, each step in the gangway should have a minimum height of 100 mm and a maximum height of 190 mm. If there are two or more rises to each row of seats, each step should be of an equal height
Regulations for the design and construction of stairs are set out in Part K of the building regulations, and compliant designs are described in Approved Document K - Protection from falling, collision and impact.
The treads of stairs are the horizontal parts which people step on.
The leading edge of the tread is described as the `nosing'. In buildings other than dwellings, the nosing should be visually contrasting, and a suitable tread nosing profile, should be used. See nosing for more information.
In buildings other than dwellings, risers should not be open to avoid feet or walking aids being caught underneath the tread during ascent, possibly causing a fall or giving occupants a feeling of insecurity. For dwellings, steps may have open risers if treads overlap by a minimum of 16 mm and steps are constructed so that a 100 mm diameter sphere cannot pass through the open risers.
A tapered tread is a step in which the going reduces from one side to the other. Where stairs have tapered treads, consecutive treads should use the same going. If a stair consists of straight and tapered treads, the going of the tapered treads should not be less than the going of the straight treads.
Alternating tread stairs are stairs with paddle-shaped treads where the wide portion is on alternate sides on consecutive treads. In dwellings, alternating tread stairs may only be used in loft conversions where there is not enough space for conventional stairs and where the stair is for access to only one habitable room and, if desired, a bathroom and/or a WC (although this must not be the only WC in the dwelling).
Alternating tread stairs should; make alternating steps uniform with parallel nosings, have slip-resistant surfaces on treads, have tread sizes over the wider part of the step in line with the table above, should provide a minimum clear headroom of 2 m, should be constructed so that a 100 mm diameter sphere cannot pass through the open risers and should comply with the diagram below.
Structural element: - Stringer (aircraft), or longeron, a strip of wood or metal to which the skin of an aircraft is fastened
Stringer (aircraft), or longeron, a strip of wood or metal to which the skin of an aircraft is fastened
Stringer (slag), an inclusion, possibly leading to a defect, in cast metal
Stringer (stairs), the structural member in a stairway that supports the treads and risers
Stringer (surfing), a thin piece of wood running from nose to tail of a surfboard
Sustainability in building design and construction - Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (ref. Brundtland Commission, Our Common Future, 1987).
Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (ref. Brundtland Commission, Our Common Future, 1987).
Some broader descriptions include social and economic sustainability (which along with environmental sustainability comprise the three pillars of sustainability) although these can confuse the basic issue of the depletion of resources.
Sustainability in building developments is a vast and complex subject that must be considered from the very earliest stages as the potential environmental impacts are very significant (ref. Technology Strategy Board).
The built environment accounts for: -
45% of total UK carbon emissions (27% from domestic buildings and 18% from non-domestic).
72% of domestic emissions arise from space heating and the provision of hot water.
32% of landfill waste comes from the construction and demolition of buildings.
13% of products delivered to construction sites are sent directly to landfill without being used.
Once it has been decided to build a new building, as opposed to say changing working practices or refurbishing an existing building, a very significant commitment to consume resources has already been made. Designers and contractors may be able to help limit that consumption, but they cannot change the overall commitment.
This consumption of resources can be even more significant if the client makes a decision to relocate, with the impact this has on their staff, requiring that they either move house or change their travel plans. Decisions such as this which are often made outside of any environmental assessment process can have a far greater impact on sustainability than decisions that designers are able to influence such as the form of the building and selection of materials.
Key decisions may be picked up by an environmental impact assessment on larger projects, but even then, this can be a post-rationalisation process used to justify decisions to the local planning authority, rather than a genuine decision-making process.
Clients may wish therefore to appoint an independent client adviser with specialist knowledge of sustainability during the very early stages of their project (before the consultant team has been appointed) to help them address these high-level decisions.
Clients may have an existing environmental policy, that sets out an overall sustainability vision, as well as detailed objectives and targets. They may also have environmental accreditation such as ISO 14000 (a series of standards which provides a framework for environmental management).
Other standards may be imposed by funders, the building regulations, and planning legislation (including the possible need for an environmental impact assessment). It is wise however to write a specific environmental plan for the development being considered, as building projects involve many detailed issues that go beyond the scope of an existing corporate plan.
A project-specific environmental plan could form part of the brief, or on larger projects might be a stand-alone document. It might include an overall vision, objectives and specific targets in relation to:
Business planning: -
The need for a new building as opposed to doing nothing, refurbishment or changes in working practices.
Selection of consultants: -
Contractual requirements in relation to the selection of materials, monitoring and reporting, track record, environmental accreditation and qualifications of staff.
Selection of location: -
Availability of transport, the selection of a greenfield or brownfield site, the local availability of resources and services, the local infrastructure and local ecology.
Project brief: -
Procurement route, travel plan, working methods, standards, ecology and landscape, energy use and energy source, flexibility and durability, waste management, water management, material selection and pollution.
Design: -
Energy use and energy source, embodied energy, use of harmful materials, material sources, ecology and landscape, flexibility and durability, waste management, water management, disposal, travel plan and pollution.
Tender: -
Contractual requirements such as monitoring and reporting, working practices, track record, environmental accreditation and qualifications of staff.
Construction: -
Transport, embodied energy, use of harmful materials, material sources, working methods, site waste management plan, recycling, pollution, wheel washing, dust generation and noise nuisance.
Operation: -
Energy source, energy use, water management, maintenance, resource management, waste management, flexibility, durability, landscape and ecology, pollution, evaluation and feedback.
Resilience: -
Resilience to climate change. -
Disposal: -
Dismantling and demolition, re-use, re-sale and recycling, landscape and ecology, hazardous materials and pollution.
The environmental plan should: -
Set specific, measurable targets. - Set standards that must be adhered to.
Set standards that must be adhered to. - Establish risks and mitigation measures.
Establish risks and mitigation measures. - Establish procedures for communication and training.
Establish procedures for communication and training. - Establish procedures for monitoring and reporting.
Establish procedures for monitoring and reporting. - Establish procedures for revision and updating.
Establish procedures for revision and updating. - Environmental plans require policing, and on a large project this can be a full-time job for a specialist. At the client level, a senior champion should be appointed to take responsibility for environmental matters.
Environmental plans require policing, and on a large project this can be a full-time job for a specialist. At the client level, a senior champion should be appointed to take responsibility for environmental matters.
Predicting the likely environmental performance of a development during the design phase is becoming more important as regulations become increasing strict.
As well as the building regulations, and government targets for low carbon construction (see Low carbon construction plan), the National Planning Policy Framework makes clear that there should be a presumption in favour of granting planning permission for sustainable development, this might include low-carbon developments, and developments with resilience to climate change. This should be reflected in design and access statements for outline planning applications.
There are a number of assessment tools and standards available to help assess environmental performance:
BREEAM. - Passivhaus.
Passivhaus. - SAP the Government's Standard Assessment Procedure for energy rating of dwellings.
SAP the Government's Standard Assessment Procedure for energy rating of dwellings.
Leadership in Energy and Environmental Design (LEED), an international green building certification system.
The code for sustainable homes. - These assessment techniques are beginning to allow whole-life costing to form a fundamental part of the design process as it becomes possible to demonstrate that higher initial costs can sometimes result in lower long-term impacts and greater long-term benefits. Demonstration of actual performance in use may be necessary through requirements for a Energy Performance Certificates (EPCs) or Display Energy Certificates (DECs)
These assessment techniques are beginning to allow whole-life costing to form a fundamental part of the design process as it becomes possible to demonstrate that higher initial costs can sometimes result in lower long-term impacts and greater long-term benefits. Demonstration of actual performance in use may be necessary through requirements for a Energy Performance Certificates (EPCs) or Display Energy Certificates (DECs)
Appointments should make clear the extent and standard of environmental performance and assessment that is required.
Introduction - Beams are structural elements that resists loads applied laterally to their axis. They typically transfer loads imposed along their length to their end points where the loads are transferred to walls, columns, foundations, and so on.
Beams are structural elements that resists loads applied laterally to their axis. They typically transfer loads imposed along their length to their end points where the loads are transferred to walls, columns, foundations, and so on.
Beams may be: -
Simply supported: that is, they are supported at both ends but are free to rotate.
Fixed: Supported at both ends and fixed to resist rotation.
Overhanging: overhanging their supports at one or both ends.
Continuous: extending over more than two supports.
Cantilevered: supported only at one end. See Cantilever for more information.
They may be statically determinate, that is, their reactions can be solved using equilibrium conditions, or they can be statically indeterminate.
Historically, beams were formed from timber, but they may also be manufactured from steel, or concrete or they may be composite constructions.
A wide variety of cross section shapes are commonly available, including; square, rectangular, circular, I-shaped, T-shaped, H-shaped, C-shaped, tubular, and so on.
Beams may be straight, curved or tapered.
Common beams (not comprehensive, please add to this list)
Universal beam - A universal beam (UB) is a beam with an 'I' or 'H'-shaped cross-section available in variety of standard sizes. It is a very efficient form for carrying bending and shear loads in the plane of the web.
A universal beam (UB) is a beam with an 'I' or 'H'-shaped cross-section available in variety of standard sizes. It is a very efficient form for carrying bending and shear loads in the plane of the web.
The standard method for specifying the dimensions of a standard hot-rolled steel section includes using initials to designate the type of section. For example:
'UB 203 x 133 x 25' - A universal beam of nominal dimensions 203 mm deep, 133 mm wide, and weight 25 kg/m.
Trussed beam - Trussed beams are strengthened by the addition of cables or rods to form a truss
Trussed beams are strengthened by the addition of cables or rods to form a truss
Hip beam - Hip beams are common in roofs, where they form the angled, inclined hip of the roof, supporting other load-bearing beams (or rafters) which branch away from them on either side and slope down to the eaves.
Hip beams are common in roofs, where they form the angled, inclined hip of the roof, supporting other load-bearing beams (or rafters) which branch away from them on either side and slope down to the eaves.
Composite beam - Composite beams are beams formed from two or more dissimilar materials, such as concrete-steel beams. Downstand beams, flitch beams and shallow floors are examples of composite beams.
Composite beams are beams formed from two or more dissimilar materials, such as concrete-steel beams. Downstand beams, flitch beams and shallow floors are examples of composite beams.
See Concrete-steel composite structures for more information -
Open web beam - Open web beams are commonly used for structures that require long spans with light-to-moderate loading.
Open web beams are commonly used for structures that require long spans with light-to-moderate loading.
See Open web beam for more information. -
Lattice beam - Lattice beams are an alternative to open web beams and can be used for spans of up to 15 m with high depth-to-weight ratios. They can be plate girder lattice beams or tubular lattice beams.
Lattice beams are an alternative to open web beams and can be used for spans of up to 15 m with high depth-to-weight ratios. They can be plate girder lattice beams or tubular lattice beams.
See Lattice beam for more information. -
Beam bridge - Beam bridges are simple forms of bridges comprising a beam-like deck supported at both ends by abutments or piers.
Beam bridges are simple forms of bridges comprising a beam-like deck supported at both ends by abutments or piers.
See Beam bridges for more information. -
Chilled beam - Chilled beams are used to provide cooling to the internal spaces of buildings. Typically, chilled beams are distributed regularly across the ceiling of a space. They include chilled water pumped through copper cooling coils bonded to aluminium fins that cool air by convection.
Chilled beams are used to provide cooling to the internal spaces of buildings. Typically, chilled beams are distributed regularly across the ceiling of a space. They include chilled water pumped through copper cooling coils bonded to aluminium fins that cool air by convection.
See Chilled beam for more information. -
Tie beam - 'A horizontal beam connecting two rafters in a roof or roof truss.' Ref Drawing for Understanding, Creating Interpretive Drawings of Historic Buildings, published by Historic England in 2016.
'A horizontal beam connecting two rafters in a roof or roof truss.' Ref Drawing for Understanding, Creating Interpretive Drawings of Historic Buildings, published by Historic England in 2016.
In the construction industry, the term `frame' typically refers to a rigid structure that supports a building or other built asset such as a bridge or tunnel, or parts of them.
Introduction - Stairs are used to create a pedestrian route between different vertical levels by dividing the height between the levels into manageable steps. Very generally, the word 'stairs' refers to a staircase, whereas the word 'step' refers to the steps that make up the staircase.
Stairs are used to create a pedestrian route between different vertical levels by dividing the height between the levels into manageable steps. Very generally, the word 'stairs' refers to a staircase, whereas the word 'step' refers to the steps that make up the staircase.
The type of stairs suitable for different situations will depend on:
The supporting structure. - The amount and type of usage it is likely to receive.
The amount and type of usage it is likely to receive.
The space available and its geometry. - The difference in height between the top and bottom.
The difference in height between the top and bottom.
Materials selection - Stairs may be:
Stairs may be: -
Open tread or closed tread. - Provided with handrails on one or both sides, or in the middle on wide stairs.
Provided with handrails on one or both sides, or in the middle on wide stairs.
Enclosed by walls or open on one or both side.
Different widths and lengths and may have a range of step dimensions.
Different geometries. - Geometries
Geometries - Some of the most common types of stair geometry include:
Some of the most common types of stair geometry include:
Straight - Generally the most prevalent type of stairs, straight stairs comprise a single linear flight which does not change direction.
Generally the most prevalent type of stairs, straight stairs comprise a single linear flight which does not change direction.
Where there are more than 36 risers in consecutive flights of stairs, Approved Document K requires that there is at least one change of direction, with a landing that has a minimum length equal to the width of the stairs.
Quarter-turn - Quarter-turn, or L-shaped, stairs comprise a straight flight of stairs that makes a 90-degree turn after a landing. This type can be considered safer than a straight staircase since the landing reduces the number of treads in one flight and provides a place to rest.
Quarter-turn, or L-shaped, stairs comprise a straight flight of stairs that makes a 90-degree turn after a landing. This type can be considered safer than a straight staircase since the landing reduces the number of treads in one flight and provides a place to rest.
Winder - This type of stairs is similar to a quarter-turn staircase, but consists of winders which are wedge-shaped treads, wider on one side than the other. Winders allow a turn by 90-degrees (single winder) or 180-degrees (double winder).
This type of stairs is similar to a quarter-turn staircase, but consists of winders which are wedge-shaped treads, wider on one side than the other. Winders allow a turn by 90-degrees (single winder) or 180-degrees (double winder).
Half-turn - Half-turn, or U-shaped, stairs comprise two straight flights of stairs that make a 180-degree turn having been separated by a landing.
Half-turn, or U-shaped, stairs comprise two straight flights of stairs that make a 180-degree turn having been separated by a landing.
Spiral - This type of stair is a compact design with flights resembling a circle (or part of a circle), and centred around a single vertical column. Similar to winder stairs, the treads are wedge-shaped but differ in that they are all uniformly sized (except the final one).
This type of stair is a compact design with flights resembling a circle (or part of a circle), and centred around a single vertical column. Similar to winder stairs, the treads are wedge-shaped but differ in that they are all uniformly sized (except the final one).
Although spiral stairs are often considered to be aesthetically pleasing and effective in terms of space, they may not be the most convenient in terms of frequent use as the treads can often be less easy or safe to traverse than other types of stairs.
Helical - A helical stair similar to a spiral stair, but the helix wraps around a central void rather than a column.
A helical stair similar to a spiral stair, but the helix wraps around a central void rather than a column.
Curved - Also known as arched stairs, this type of stair comprises a continuous flight that is shaped like an arch, with no landings. The treads are wedge-shaped similar to winder stairs. Although achieving an elegant aesthetic, curved stairs are difficult to construct since all basic details, banisters, and so on, need to be curved.
Also known as arched stairs, this type of stair comprises a continuous flight that is shaped like an arch, with no landings. The treads are wedge-shaped similar to winder stairs. Although achieving an elegant aesthetic, curved stairs are difficult to construct since all basic details, banisters, and so on, need to be curved.
Bifurcated - Bifurcated stairs comprise a grand and sweeping set of stairs that divides into two smaller flights that split off into opposite directions.
Bifurcated stairs comprise a grand and sweeping set of stairs that divides into two smaller flights that split off into opposite directions.
Compact - This type of stairs, also known as narrow stairs, are often designed as a solution to confined space within a building. They comprise distinctive treads that are designed to take one foot only.
This type of stairs, also known as narrow stairs, are often designed as a solution to confined space within a building. They comprise distinctive treads that are designed to take one foot only.
Alternating tread - A stair with paddle-shaped treads where the wide portion is on alternate sides on consecutive treads.
A stair with paddle-shaped treads where the wide portion is on alternate sides on consecutive treads.
Uses - Different types of stair use include:
Different types of stair use include: -
Utility stair - Approved document K defines a 'utility stair' as '...a stair used for escape, access for maintenance, or purposes other than as the usual route for moving between levels on a day-to-day basis.'
Approved document K defines a 'utility stair' as '...a stair used for escape, access for maintenance, or purposes other than as the usual route for moving between levels on a day-to-day basis.'
General access stair - Approved document K defines a 'general access stair' as '...a stair intended for all users of a building on a day-to-day basis, as a normal route between levels.'
Approved document K defines a 'general access stair' as '...a stair intended for all users of a building on a day-to-day basis, as a normal route between levels.'
Private stair - Approved document K defines a 'private stair' as '...a stair intended to be used for only one dwelling'
Approved document K defines a 'private stair' as '...a stair intended to be used for only one dwelling'
Protected stair - Approved document B defines a `protected stair' as `...a stair discharging through a final exit to a place of safety (including any exit passageway between the foot of the stair and the final exit) that is adequately enclosed with fire resisting construction'.
Approved document B defines a `protected stair' as `...a stair discharging through a final exit to a place of safety (including any exit passageway between the foot of the stair and the final exit) that is adequately enclosed with fire resisting construction'.
See: Protected stairway for more information. -
Firefighting stair - Approved document B defines a `firefighting stair' as `... a protected stairway communicating with the accommodation area through a firefighting lobby'.
Approved document B defines a `firefighting stair' as `... a protected stairway communicating with the accommodation area through a firefighting lobby'.
Common stair - Approved document B defines a `common stair' as `... an escape stair serving more than one flat'.
Approved document B defines a `common stair' as `... an escape stair serving more than one flat'.
The Unbounded Height parameter shows the largest potential height of the room, based on the room height parameters. This value is read-only. (The room's actual height may be changed by room-bounding elements, such as intervening floors and roofs.
The term `volume' generally refers to a measurement of a three-dimensional shape that is enclosed by a closed surface. It is used to specify the amount of space that a substance such as a solid, liquid or gas occupies.
As per the International System of Units (SI), the standard unit of volume is the cubic metre (m). The cubic metre measurement indicates the volume contained within a cube the edges of which are all 1 m long.
To be able to calculate the volume of simple shapes (e.g. regular, right angled, straight-edged), arithmetic formulae can be used, such as:
Volume = length x width x height -
Whereas, more complex shapes require integral calculus if there is a formula for the shape's boundary.
The term `volume' is also used in relation to sound levels, i.e. how loud or quiet a sound is. The higher the intensity of a sound, the louder it is perceived by the ear, and the higher its volume. Decibels (dB) are most commonly used as a measure of sound volume. The decibel scale gives an approximation of human perception of relative loudness.
In our experience, warranties are one of the most misunderstood concepts in the construction industry. Many owners, designers and contractors think they have put a one-year warranty in their contracts, when in fact they are 100% wrong.
Many times, they don't even understand what a warranty is. Most of the time, they don't understand what it covers, and how long the contractor or vendor is on the hook.
What is a warranty? - A warranty is a representation made by one party upon which another party may rely. It is not the same as a guarantee (which is a promise to stand for the debt of another) even though many contracts use the terms interchangeably. Warranties may be express (written in the contract or stated orally), implied (by the common law) or statutory (set forth in a state's statutes).
A warranty is a representation made by one party upon which another party may rely. It is not the same as a guarantee (which is a promise to stand for the debt of another) even though many contracts use the terms interchangeably. Warranties may be express (written in the contract or stated orally), implied (by the common law) or statutory (set forth in a state's statutes).
Most, if not all, construction contracts contain warranties. Examples of express warranties routinely included in construction contracts are:
A warranty that work will be performed in a good and workmanlike manner;
A warranty that materials will be new and of good quality; and
A warranty that the work will conform to the requirements of the contract documents.
In limited circumstances, courts have implied warranties to protect parties where there were no express warranties to do so. The theory is that in some circumstances the parties intended a warranty to apply even though the contract doesn't expressly say so. The warranty of "habitability" that runs from homebuilders to the purchaser of the home is an example of an implied warranty.
Statutory warranties are created by legislation and become part of some contracts by operation of law. The Uniform Commercial Code, which has been enacted in some form in every state, creates statutory warranties that apply to the sale of goods.
In the construction context, purchase orders to material suppliers will usually be governed by the UCC. Further, if a subcontract is dominated by the purchase of goods more than labor, there is a chance a court will (or will not) find that the subcontract primarily concerns the sale of goods such that the UCC may apply.
UCC statutory warranties on the supplier or subcontractor include:
The warranty of fitness for a particular purpose (that the goods will serve the buyer's intended use if the seller has reason to know that intended use); and
The warranty of merchantability (that the goods will be of at least average quality, conform to the promises made on any labels and are fit for the ordinary purpose for which the goods are used).
How is a warranty different from a one-year correction period?
Many form contracts (such as the AIA) clearly differentiate between a contractor's warranty obligations (to build according to the plans and specs) and its one-year correction period (when it has the right and obligation to fix its work if it fails). One difference between the two obligations is the burden of proving why the work failed: If the work fails during the one-year period, the contractor has to fix it, no questions asked (assuming the failure wasn't due to misuse). After the one-year period, the owner has the burden of proving that the warranty was breached -- that the work wasn't done according to the plans and specs or that the part didn't last as long as it should have.
A second difference is how long the contractor is on the hook. If a contractor fails or refuses to correct work in the one-year period, the owner must file suit within the statute of limitations (say, five years), starting from the end of the one-year period. If the contractor has warranted that the work will meet the plans and specs, and (for example) a masonry wall crumbles in four years, the owner may have five years from the date of failure to bring its suit. How long the warranty exposure will go on will depend on how long the particular part of the work should have lasted: Carpet normally wears out before concrete; caulking will need to be replaced long before the windows should be expected to fail.
What happens if the two concepts get mixed up?
Frequently, we see contracts where someone has called the one-year correction period the "warranty" period and, in fact, goes so far as to say in the real warranty clause that it is for one year (perhaps longer for specific pieces of equipment). Such phrasing could result in an owner having no one to hold responsible if the building falls down in 367 days. We doubt that any owner expects to pay good money for concrete, masonry, steel or other sturdy components of a project that will fall apart after one year, but this is the mess someone could end up in by not reading and understanding the contracts.
Often, even if the warranty clause in the general conditions is clear, there is conflicting language in the front end of a project manual prepared by a designer. Contractors should pay more attention to the exact words used in their contracts. They may be surprised to find that their warranty obligations are not as great as they thought.
Can you avoid long exposures to warranty claims?
Of course, if the other party will agree to it. Most manufacturers print on their labels and in their literature that they are giving "limited" warranties only, and "disclaiming" all other warranties. Courts will typically enforce disclaimers of implied and statutory warranties as long as the disclaimer is clear and unequivocal. But you have to be careful; a failure to change all warranty language in the contract could end up creating inconsistencies that will take a judge or jury to resolve. It is not enough to draft a clear disclaimer. You also have to make sure that the entire contract is consistent with the disclaimer.
Warranties are a part of every construction contract. Those who take the time to understand how those warranties work will gain an advantage over those who do not in managing risk on their projects.
Introduction - Windows are openings fitted with glass to admit light and allow people to see out. They are often openable to allow ventilation.
Windows are openings fitted with glass to admit light and allow people to see out. They are often openable to allow ventilation.
Although the historic use of glass dates back to the Romans, glass windows only became common domestically in England in the early-17th century, gradually becoming more versatile and widespread as plate glass processes were perfected during the Industrial Age.
England, France, Ireland and Scotland introduced a window tax during the 18th and 19th centuries which was payable based on the number of windows in a house. It is still common to see buildings from that period with windows that were bricked-up to avoid the tax. The tax was repealed in 1851.
Windows are can include a number of different components:
Light - The area between the outer parts of a window, usually filled with a glass pane.
Frame - This holds the light in place and supports the window system.
Lintel - A beam over the top of a window.
Jamb - The vertical parts forming the sides of the frame.
Sill (or cill) - The bottom piece in a window frame, often projecting beyond the line of the wall.
Mullion - A vertical element between two window units or lights.
Transom - A horizontal element between two window units or lights.
Head - The uppermost member of the frame.
Sash - The frame holding the glazing. - Casement - A window (or sash) attached to its frame by one or more hinges.
Casement - A window (or sash) attached to its frame by one or more hinges.
Materials - It is important that windows be made of suitable and durable materials:
It is important that windows be made of suitable and durable materials:
With good thermal and sound insulation properties. - Capable of resisting wind, and rain.
Capable of resisting wind, and rain. - Easy to clean.
Easy to clean. - Providing safety and security.
Providing safety and security. - Most styles of windows are available in a number of different materials. Traditionally, windows were made of timber, either hardwood or softwood, and often protected against decay using paint or a natural wood finish. This finish requires regular maintenance.
Most styles of windows are available in a number of different materials. Traditionally, windows were made of timber, either hardwood or softwood, and often protected against decay using paint or a natural wood finish. This finish requires regular maintenance.
Steel and aluminium alloy windows are capable of creating larger areas of glass with a thinner frame. However, historically, these could give rise to condensation on the metal components.
PVC windows are capable of providing excellent heat and sound insulation, as well as requiring little maintenance. However, they may have a shorter life than a well-maintained timber window.
The efficiency of windows is improved by double glazing, treble glazing, low-e coatings, the construction of the frame, the type of glass, the gas used to fill the sealed unit and so on. Generally, more efficient windows are more expensive, but the capital cost may be recovered during the life of the window life through lower energy bills. In addition, the conditions within the enclosed space are likely to be more comfortable.
The BFRC Window Energy Rating (WER) scheme is based on a traffic-light style A-G ratings system for energy efficiency similar to that used for fridges, washing machines, cookers and so on. An A rating indicates a good level of energy efficiency, whilst G is the lowest possible rating.
Opening type - Fixed light
Fixed light - A window that is fixed in place and cannot be opened. Often used where light or vision alone is required rather than ventilation, but fixed lights are commonly used in conjunction with other openable types of window.
A window that is fixed in place and cannot be opened. Often used where light or vision alone is required rather than ventilation, but fixed lights are commonly used in conjunction with other openable types of window.
Vertical slider/sash - Glass is fitted in `sashes' (moveable panels) that slide vertically past each other:
Glass is fitted in `sashes' (moveable panels) that slide vertically past each other:
Single-hung sash: One sash is moveable and the other is fixed.
Double-hung sash: Sashes are hung on spring balances or counterweights and made up of two sashes that overlap slightly and slide up and down vertically inside the frame.
Horizontal sliding sash: Two sashes that overlap slightly and slide horizontally on guide rails within the frame.
Casement - An opening window fixed to the frame by hinges along one of its edges:
An opening window fixed to the frame by hinges along one of its edges:
Side hung casement: The sash side opens outwards.
Top hung casement: The sash top opens outwards. Also known as awning windows.
Bottom hung casement: The sash bottom opens inwards. Also known as hopper windows.
Casement windows preceded sash windows in the UK and traditionally opened inwards, although now they more commonly open outwards so as to free space inside and better direct air inwards for ventilation.
Casement windows require a metal bar called a `stay' to hold them open. Different types are available such as the peg type (the stay has holes along it which allow it to fit over pegs), telescopic (tube shaped), and friction (a bent arm allows the window to open to 180-degrees).
Tilt and turn - Tilt and turn windows Include a mechanism that allows them to tilt inwards from one edge or to open inwards from one side. The stability of the mechanism allows tilt and turn windows to be larger than casement windows. They are also easy to clean from the inside.
Tilt and turn windows Include a mechanism that allows them to tilt inwards from one edge or to open inwards from one side. The stability of the mechanism allows tilt and turn windows to be larger than casement windows. They are also easy to clean from the inside.
Pivot - Pivot windows are hung on one hinge at centre points on each of two opposite sides. This allows the window to revolve when opened. The pivots can either be vertical, with the hinges mounted top and bottom, or horizontal, with the hinges mounted at each jamb. Pivot hinges incorporate a friction device that enables the window to hold itself open against its own weight. Pivot windows tend to be more expensive than casement windows but can allow for easy cleaning access.
Pivot windows are hung on one hinge at centre points on each of two opposite sides. This allows the window to revolve when opened. The pivots can either be vertical, with the hinges mounted top and bottom, or horizontal, with the hinges mounted at each jamb. Pivot hinges incorporate a friction device that enables the window to hold itself open against its own weight. Pivot windows tend to be more expensive than casement windows but can allow for easy cleaning access.
Bi-fold - These are made up of a number of individual sashes, usually 2, 3 or 4, hinged together. They can be opened up in a concertina style and stacked neatly against each other at the side of the window frame.
These are made up of a number of individual sashes, usually 2, 3 or 4, hinged together. They can be opened up in a concertina style and stacked neatly against each other at the side of the window frame.
Louvre - These windows use a series of parallel pieces of glazing that are hung on centre pivots positioned at intervals down the vertical jambs that allow them to open and close using a crank or lever. They allow for good ventilation with only small projections.
These windows use a series of parallel pieces of glazing that are hung on centre pivots positioned at intervals down the vertical jambs that allow them to open and close using a crank or lever. They allow for good ventilation with only small projections.
Other types - Tilt and slide window - The sash tilts inwards at the top and slides horizontally behind the fixed pane.
Tilt and slide window - The sash tilts inwards at the top and slides horizontally behind the fixed pane.
Toplight - These are usually above doors. - Sidelight - Positioned beside a door or main window.
Sidelight - Positioned beside a door or main window.
Skylight - These are windows positioned in the roof. The brand name `Velux' has become associated with opening domestic rooflights.
Clerestory - Bands of windows across the tops of buildings that allow natural light in without compromising privacy or security.
Bay window - Multi-panel windows that project in front of the external wall line, being supported by a sill height wall.
Bow window - A curved bay window. - Multi-lite window - Windows glazed with small panes of glass separated by glazing bars, or muntins.They can be arranged decoratively to suit aesthetic needs or architectural styles.
Multi-lite window - Windows glazed with small panes of glass separated by glazing bars, or muntins.They can be arranged decoratively to suit aesthetic needs or architectural styles.
Stained glass window - Decorative windows made of coloured glass separated by glazing bars, popular in churches and Victorian houses.
Topguided - Tracks and slides enable the top to slide downwards whist the bottom opens out.
Sidehung - A variation on a casement window, side opening controlled by tracks and slides.
Dormer window - A small roofed structure that projects outwards from the main pitched roof of a building. See Dormer window for more information.
Rooflight - A dome light, lantern light, skylight, ridge light, glazed barrel vault or other element intended to admit daylight through a roof.
Roof window - A window that is in the same plane as the surrounding roof, and has a minimum pitch of 15-degrees. See also Velux window.
For more information, see Domestic windows. -
Number of panes - Thermal performance and acoustic requirements will typically determine the need for:
Thermal performance and acoustic requirements will typically determine the need for:
Single glazing. - Double glazing.
Double glazing. - Triple glazing.
Triple glazing. - Secondary glazing.
Secondary glazing. -
Noun: - z-direction
z-direction - (algebraic geometry) The direction aligned with the z-axis of a coordinate system.
(algebraic geometry) The direction aligned with the z-axis of a coordinate system.
Size - Size
Size - In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter".[1] Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches.
In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter".[1] Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches.
Size in general is the magnitude or dimensions of a thing. More specifically, geometrical size (or spatial size) can refer to linear dimensions (length, width, height, diameter, perimeter), area, or volume. Size can also be measured in terms of mass, especially when assuming a density range.
"Physical dimension" redirects here. For the dimension of a physical quantity, see Dimension (physics).
A diagram comparing the size of an average human diver to the size of the modern great white shark, whale shark, and the prehistoric megalodon. The illustration also contains a linear measurement in meters in the middle.
A size comparison illustration comparing the sizes of various planets and stars. In each grouping after the first, the last object from the previous group is presented as the first object of the following group, to present a continuous sense of comparison.
A bat skull next to a ruler used to measure size. Size: 7 mm (0.28 in)
A finch egg next to a dime; a person familiar with the size of a dime would thereby have a sense of the size of the egg.
Forced perspective illusion wherein the perceived size of the Sphinx next to a human is distorted by the incomplete view of both, and the appearance of physical contact between the two.
This animation gives a sense of the scale of some of the known objects in our universe.
In mathematical terms, "size is a concept abstracted from the process of measuring by comparing a longer to a shorter".[1] Size is determined by the process of comparing or measuring objects, which results in the determination of the magnitude of a quantity, such as length or mass, relative to a unit of measurement. Such a magnitude is usually expressed as a numerical value of units on a previously established spatial scale, such as meters or inches.
The sizes with which humans tend to be most familiar are body dimensions (measures of anthropometry), which include measures such as human height and human body weight. These measures can, in the aggregate, allow the generation of commercially useful distributions of products that accommodate expected body sizes,[2] as with the creation of clothing sizes and shoe sizes, and with the standardization of door frame dimensions, ceiling heights, and bed sizes. The human experience of size can lead to a psychological tendency towards size bias,[3] wherein the relative importance or perceived complexity of organisms and other objects is judged based on their size relative to humans, and particularly whether this size makes them easy to observe without aid.
Contents - Humans most frequently perceive the size of objects through visual cues.[4] One common means of perceiving size is to compare the size of a newly observed object with the size of a familiar object whose size is already known. Binocular vision gives humans the capacity for depth perception, which can be used to judge which of several objects is closer, and by how much, which allows for some estimation of the size of the more distant object relative to the closer object. The perception of size can be distorted by manipulating these cues, for example through the creation of forced perspective.
Humans most frequently perceive the size of objects through visual cues.[4] One common means of perceiving size is to compare the size of a newly observed object with the size of a familiar object whose size is already known. Binocular vision gives humans the capacity for depth perception, which can be used to judge which of several objects is closer, and by how much, which allows for some estimation of the size of the more distant object relative to the closer object. The perception of size can be distorted by manipulating these cues, for example through the creation of forced perspective.
Some measures of size may also be determined by sound. Visually impaired humans often use echolocation to determine features of their surroundings, such as the size of spaces and objects. However, even humans who lack this ability can tell if a space that they are unable to see is large or small from hearing sounds echo in the space. Size can also be determined by touch, which is a process of haptic perception.
The sizes of objects that can not readily be measured merely by sensory input may be evaluated with other kinds of measuring instruments. For example, objects too small to be seen with the naked eye may be measured when viewed through a microscope, while objects too large to fit within the field of vision may be measured using a telescope, or through extrapolation from known reference points. However, even very advanced measuring devices may still present a limited field of view.
Objects being described by their relative size are often described as being comparatively big and little, or large and small, although "big and little tend to carry affective and evaluative connotations, whereas large and small tend to refer only to the size of a thing".[5] A wide range of other terms exist to describe things by their relative size, with small things being described for example as tiny, miniature, or minuscule, and large things being described as, for example, huge, gigantic, or enormous. Objects are also typically described as tall or short specifically relative to their vertical height, and as long or short specifically relative to their length along other directions.
Although the size of an object may be reflected in its mass or its weight, each of these is a different concept. In scientific contexts, mass refers loosely to the amount of "matter" in an object (though "matter" may be difficult to define), whereas weight refers to the force experienced by an object due to gravity.[6] An object with a mass of 1.0 kilogram will weigh approximately 9.81 newtons (newton is the unit of force, while kilogram is the unit of mass) on the surface of the Earth (its mass multiplied by the gravitational field strength). Its weight will be less on Mars (where gravity is weaker), more on Saturn, and negligible in space when far from any significant source of gravity, but it will always have the same mass. Two objects of equal size, however, may have very different mass and weight, depending on the composition and density of the objects. By contrast, if two objects are known to have roughly the same composition, then some information about the size of one can be determined by measuring the size of the other, and determining the difference in weight between the two. For example, if two blocks of wood are equally dense, and it is known that one weighs ten kilograms and the other weighs twenty kilograms, and that the ten kilogram block has a volume of one cubic foot, then it can be deduced that the twenty kilogram block has a volume of two cubic feet.
The concept of size is often applied to ideas that have no physical reality. In mathematics, magnitude is the size of a mathematical object, which is an abstract object with no concrete existence. Magnitude is a property by which the object can be compared as larger or smaller than other objects of the same kind. More formally, an object's magnitude is an ordering (or ranking) of the class of objects to which it belongs. There are various other mathematical concepts of size for sets, such as:
cardinality (equal if there is a bijection), of a set is a measure of the "number of elements of the set"
for well-ordered sets: ordinal number (equal if there is an order-isomorphism)
In statistics (hypothesis testing), the "size" of the test refers to the rate of false positives, denoted by . In astronomy, the magnitude of brightness or intensity of a star is measured on a logarithmic scale. Such a scale is also used to measure the intensity of an earthquake, and this intensity is often referred to as the "size" of the event.[7] In computing, file size is a measure of the size of a computer file, typically measured in bytes. The actual amount of disk space consumed by the file depends on the file system. The maximum file size a file system supports depends on the number of bits reserved to store size information and the total size of the file system in terms of its capacity to store bits of information.
In poetry, fiction, and other literature, size is occasionally assigned to characteristics that do not have measurable dimensions, such as the metaphorical reference to the size of a person's heart as a shorthand for describing their typical degree of kindness or generosity. With respect to physical size, the concept of resizing is occasionally presented in fairy tales, fantasy, and science fiction, placing humans in a different context within their natural environment by depicting them as having physically been made exceptionally large or exceptionally small through some fantastic means.
^ C. Smoryski, History of Mathematics: A Supplement (2008), p. 76.
^ Thomas T. Samaras, Human Body Size and the Laws of Scaling (2007), p. 3.
^ Clifford N. Matthews, Roy Abraham Varghese, Cosmic Beginnings and Human Ends: Where Science and Religion Meet (2995), p. 208: "The notion that bacteria are primitive, unsophisticated organisms stems from what I would call size chauvinism".
^ Bennett L. Schwartz, John H. Krantz, Sensation and Perception (2015), Chapter 7: "Depth and Size Perception", p. 169-199.
^ John R. Taylor, The Mental Corpus: How Language is Represented in the Mind (2012), p. 108.
^ See, e.g., Robert A. Meyers, Extreme Environmental Events: Complexity in Forecasting and Early Warning (2010), p. 364, stating "[t]he corner frequency scales with the size of the earthquake measured by the seismic moment".
Color (North American English), or colour (Commonwealth English), is the characteristic of visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of photoreceptor cells (in particular cone cells in the human eye and other vertebrate eyes) by electromagnetic radiation (in the visible spectrum in the case of humans). Color categories and physical specifications of color are associated with objects through the wavelengths of the light that is reflected from them and their intensities. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc.
Colors can appear different depending on their surrounding colors and shapes. In this optical illusion, the two small squares have exactly the same color, but the right one looks slightly darker.
By defining a color space, colors can be identified numerically by coordinates, which in 1931 were also named in global agreement with internationally agreed color names like mentioned above (red, orange, etc.) by the International Commission on Illumination. The RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564580 nm (red); medium-wavelength, peaking near 534545 nm (green); and short-wavelength light, near 420440 nm (blue).[1][2] There may also be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a color's colorfulness).
The photo-receptivity of the "eyes" of other species also varies considerably from that of humans and so results in correspondingly different color perceptions that cannot readily be compared to one another. Honey bees and bumblebees have trichromatic color vision sensitive to ultraviolet but insensitive to red. Papilio butterflies possess six types of photoreceptors and may have pentachromatic vision.[3] The most complex color vision system in the animal kingdom has been found in stomatopods (such as the mantis shrimp) with up to 12 spectral receptor types thought to work as multiple dichromatic units.[4]
The science of color is sometimes called chromatics, colorimetry, or simply color science. It includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (that is, what is commonly referred to simply as light).
Most light sources emit light at many different wavelengths; a source's spectrum is a distribution giving its intensity at each wavelength. Although the spectrum of light arriving at the eye from a given direction determines the color sensation in that direction, there are many more possible spectral combinations than color sensations. In fact, one may formally define a color as a class of spectra that give rise to the same color sensation, although such classes would vary widely among different species, and to a lesser extent among individuals within the same species. In each such class the members are called metamers of the color in question. This effect can be visualized by comparing the light sources' spectral power distributions and the resulting colors.
Spectral colors - The familiar colors of the rainbow in the spectrumnamed using the Latin word for appearance or apparition by Isaac Newton in 1671include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate frequencies (in terahertz) and wavelengths (in nanometers) for various pure spectral colors. The wavelengths listed are as measured in air or vacuum (see refractive index).
The familiar colors of the rainbow in the spectrumnamed using the Latin word for appearance or apparition by Isaac Newton in 1671include all those colors that can be produced by visible light of a single wavelength only, the pure spectral or monochromatic colors. The table at right shows approximate frequencies (in terahertz) and wavelengths (in nanometers) for various pure spectral colors. The wavelengths listed are as measured in air or vacuum (see refractive index).
The color table should not be interpreted as a definitive listthe pure spectral colors form a continuous spectrum, and how it is divided into distinct colors linguistically is a matter of culture and historical contingency (although people everywhere have been shown to perceive colors in the same way[6]). A common list identifies six main bands: red, orange, yellow, green, blue, and violet. Newton's conception included a seventh color, indigo, between blue and violet. It is possible that what Newton referred to as blue is nearer to what today is known as cyan, and that indigo was simply the dark blue of the indigo dye that was being imported at the time.[7]
The intensity of a spectral color, relative to the context in which it is viewed, may alter its perception considerably; for example, a low-intensity orange-yellow is brown, and a low-intensity yellow-green is olive green.
Color of objects - The color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which normally depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as potentially on the angles of illumination and viewing. Some objects not only reflect light, but also transmit light or emit light themselves, which also contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but also on a host of contextual cues, so that color differences between objects can be discerned mostly independent of the lighting spectrum, viewing angle, etc. This effect is known as color constancy.
The color of an object depends on both the physics of the object in its environment and the characteristics of the perceiving eye and brain. Physically, objects can be said to have the color of the light leaving their surfaces, which normally depends on the spectrum of the incident illumination and the reflectance properties of the surface, as well as potentially on the angles of illumination and viewing. Some objects not only reflect light, but also transmit light or emit light themselves, which also contributes to the color. A viewer's perception of the object's color depends not only on the spectrum of the light leaving its surface, but also on a host of contextual cues, so that color differences between objects can be discerned mostly independent of the lighting spectrum, viewing angle, etc. This effect is known as color constancy.
The upper disk and the lower disk have exactly the same objective color, and are in identical gray surroundings; based on context differences, humans perceive the squares as having different reflectances, and may interpret the colors as different color categories; see checker shadow illusion.
Some generalizations of the physics can be drawn, neglecting perceptual effects for now:
Light arriving at an opaque surface is either reflected "specularly" (that is, in the manner of a mirror), scattered (that is, reflected with diffuse scattering), or absorbedor some combination of these.
Opaque objects that do not reflect specularly (which tend to have rough surfaces) have their color determined by which wavelengths of light they scatter strongly (with the light that is not scattered being absorbed). If objects scatter all wavelengths with roughly equal strength, they appear white. If they absorb all wavelengths, they appear black.[8]
Opaque objects that specularly reflect light of different wavelengths with different efficiencies look like mirrors tinted with colors determined by those differences. An object that reflects some fraction of impinging light and absorbs the rest may look black but also be faintly reflective; examples are black objects coated with layers of enamel or lacquer.
Objects that transmit light are either translucent (scattering the transmitted light) or transparent (not scattering the transmitted light). If they also absorb (or reflect) light of various wavelengths differentially, they appear tinted with a color determined by the nature of that absorption (or that reflectance).
Objects may emit light that they generate from having excited electrons, rather than merely reflecting or transmitting light. The electrons may be excited due to elevated temperature (incandescence), as a result of chemical reactions (chemiluminescence), after absorbing light of other frequencies ("fluorescence" or "phosphorescence") or from electrical contacts as in light-emitting diodes, or other light sources.
To summarize, the color of an object is a complex result of its surface properties, its transmission properties, and its emission properties, all of which contribute to the mix of wavelengths in the light leaving the surface of the object. The perceived color is then further conditioned by the nature of the ambient illumination, and by the color properties of other objects nearby, and via other characteristics of the perceiving eye and brain.
Perception - When viewed in full size, this image contains about 16 million pixels, each corresponding to a different color on the full set of RGB colors. The human eye can distinguish about 10 million different colors.[9]
When viewed in full size, this image contains about 16 million pixels, each corresponding to a different color on the full set of RGB colors. The human eye can distinguish about 10 million different colors.[9]
Development of theories of color vision - Although Aristotle and other ancient scientists had already written on the nature of light and color vision, it was not until Newton that light was identified as the source of the color sensation. In 1810, Goethe published his comprehensive Theory of Colors in which he ascribed physiological effects to color that are now understood as psychological.
Although Aristotle and other ancient scientists had already written on the nature of light and color vision, it was not until Newton that light was identified as the source of the color sensation. In 1810, Goethe published his comprehensive Theory of Colors in which he ascribed physiological effects to color that are now understood as psychological.
In 1801 Thomas Young proposed his trichromatic theory, based on the observation that any color could be matched with a combination of three lights. This theory was later refined by James Clerk Maxwell and Hermann von Helmholtz. As Helmholtz puts it, "the principles of Newton's law of mixture were experimentally confirmed by Maxwell in 1856. Young's theory of color sensations, like so much else that this marvelous investigator achieved in advance of his time, remained unnoticed until Maxwell directed attention to it."[10]
At the same time as Helmholtz, Ewald Hering developed the opponent process theory of color, noting that color blindness and afterimages typically come in opponent pairs (red-green, blue-orange, yellow-violet, and black-white). Ultimately these two theories were synthesized in 1957 by Hurvich and Jameson, who showed that retinal processing corresponds to the trichromatic theory, while processing at the level of the lateral geniculate nucleus corresponds to the opponent theory.[11]
In 1931, an international group of experts known as the Commission internationale de l'clairage (CIE) developed a mathematical color model, which mapped out the space of observable colors and assigned a set of three numbers to each.
Color in the eye - Normalized typical human cone cell responses (S, M, and L types) to monochromatic spectral stimuli
Normalized typical human cone cell responses (S, M, and L types) to monochromatic spectral stimuli
The ability of the human eye to distinguish colors is based upon the varying sensitivity of different cells in the retina to light of different wavelengths. Humans are trichromaticthe retina contains three types of color receptor cells, or cones. One type, relatively distinct from the other two, is most responsive to light that is perceived as blue or blue-violet, with wavelengths around 450 nm; cones of this type are sometimes called short-wavelength cones or S cones (or misleadingly, blue cones). The other two types are closely related genetically and chemically: middle-wavelength cones, M cones, or green cones are most sensitive to light perceived as green, with wavelengths around 540 nm, while the long-wavelength cones, L cones, or red cones, are most sensitive to light that is perceived as greenish yellow, with wavelengths around 570 nm.
Light, no matter how complex its composition of wavelengths, is reduced to three color components by the eye. Each cone type adheres to the principle of univariance, which is that each cone's output is determined by the amount of light that falls on it over all wavelengths. For each location in the visual field, the three types of cones yield three signals based on the extent to which each is stimulated. These amounts of stimulation are sometimes called tristimulus values.
The response curve as a function of wavelength varies for each type of cone. Because the curves overlap, some tristimulus values do not occur for any incoming light combination. For example, it is not possible to stimulate only the mid-wavelength (so-called "green") cones; the other cones will inevitably be stimulated to some degree at the same time. The set of all possible tristimulus values determines the human color space. It has been estimated that humans can distinguish roughly 10 million different colors.[9]
The other type of light-sensitive cell in the eye, the rod, has a different response curve. In normal situations, when light is bright enough to strongly stimulate the cones, rods play virtually no role in vision at all.[12] On the other hand, in dim light, the cones are understimulated leaving only the signal from the rods, resulting in a colorless response. (Furthermore, the rods are barely sensitive to light in the "red" range.) In certain conditions of intermediate illumination, the rod response and a weak cone response can together result in color discriminations not accounted for by cone responses alone. These effects, combined, are summarized also in the Kruithof curve, that describes the change of color perception and pleasingness of light as function of temperature and intensity.
Color in the brain - The visual dorsal stream (green) and ventral stream (purple) are shown. The ventral stream is responsible for color perception.
The visual dorsal stream (green) and ventral stream (purple) are shown. The ventral stream is responsible for color perception.
While the mechanisms of color vision at the level of the retina are well-described in terms of tristimulus values, color processing after that point is organized differently. A dominant theory of color vision proposes that color information is transmitted out of the eye by three opponent processes, or opponent channels, each constructed from the raw output of the cones: a redgreen channel, a blueyellow channel, and a blackwhite "luminance" channel. This theory has been supported by neurobiology, and accounts for the structure of our subjective color experience. Specifically, it explains why humans cannot perceive a "reddish green" or "yellowish blue", and it predicts the color wheel: it is the collection of colors for which at least one of the two color channels measures a value at one of its extremes.
The exact nature of color perception beyond the processing already described, and indeed the status of color as a feature of the perceived world or rather as a feature of our perception of the worlda type of qualiais a matter of complex and continuing philosophical dispute.
Nonstandard color perception - Color deficiency
Color deficiency - If one or more types of a person's color-sensing cones are missing or less responsive than normal to incoming light, that person can distinguish fewer colors and is said to be color deficient or color blind (though this latter term can be misleading; almost all color deficient individuals can distinguish at least some colors). Some kinds of color deficiency are caused by anomalies in the number or nature of cones in the retina. Others (like central or cortical achromatopsia) are caused by neural anomalies in those parts of the brain where visual processing takes place.
If one or more types of a person's color-sensing cones are missing or less responsive than normal to incoming light, that person can distinguish fewer colors and is said to be color deficient or color blind (though this latter term can be misleading; almost all color deficient individuals can distinguish at least some colors). Some kinds of color deficiency are caused by anomalies in the number or nature of cones in the retina. Others (like central or cortical achromatopsia) are caused by neural anomalies in those parts of the brain where visual processing takes place.
Tetrachromacy - While most humans are trichromatic (having three types of color receptors), many animals, known as tetrachromats, have four types. These include some species of spiders, most marsupials, birds, reptiles, and many species of fish. Other species are sensitive to only two axes of color or do not perceive color at all; these are called dichromats and monochromats respectively. A distinction is made between retinal tetrachromacy (having four pigments in cone cells in the retina, compared to three in trichromats) and functional tetrachromacy (having the ability to make enhanced color discriminations based on that retinal difference). As many as half of all women are retinal tetrachromats.[13]:p.256 The phenomenon arises when an individual receives two slightly different copies of the gene for either the medium- or long-wavelength cones, which are carried on the X chromosome. To have two different genes, a person must have two X chromosomes, which is why the phenomenon only occurs in women.[13] There is one scholarly report that confirms the existence of a functional tetrachromat.[14]
While most humans are trichromatic (having three types of color receptors), many animals, known as tetrachromats, have four types. These include some species of spiders, most marsupials, birds, reptiles, and many species of fish. Other species are sensitive to only two axes of color or do not perceive color at all; these are called dichromats and monochromats respectively. A distinction is made between retinal tetrachromacy (having four pigments in cone cells in the retina, compared to three in trichromats) and functional tetrachromacy (having the ability to make enhanced color discriminations based on that retinal difference). As many as half of all women are retinal tetrachromats.[13]:p.256 The phenomenon arises when an individual receives two slightly different copies of the gene for either the medium- or long-wavelength cones, which are carried on the X chromosome. To have two different genes, a person must have two X chromosomes, which is why the phenomenon only occurs in women.[13] There is one scholarly report that confirms the existence of a functional tetrachromat.[14]
Synesthesia - In certain forms of synesthesia/ideasthesia, perceiving letters and numbers (graphemecolor synesthesia) or hearing musical sounds (musiccolor synesthesia) will lead to the unusual additional experiences of seeing colors. Behavioral and functional neuroimaging experiments have demonstrated that these color experiences lead to changes in behavioral tasks and lead to increased activation of brain regions involved in color perception, thus demonstrating their reality, and similarity to real color percepts, albeit evoked through a non-standard route.
In certain forms of synesthesia/ideasthesia, perceiving letters and numbers (graphemecolor synesthesia) or hearing musical sounds (musiccolor synesthesia) will lead to the unusual additional experiences of seeing colors. Behavioral and functional neuroimaging experiments have demonstrated that these color experiences lead to changes in behavioral tasks and lead to increased activation of brain regions involved in color perception, thus demonstrating their reality, and similarity to real color percepts, albeit evoked through a non-standard route.
Afterimages - After exposure to strong light in their sensitivity range, photoreceptors of a given type become desensitized. For a few seconds after the light ceases, they will continue to signal less strongly than they otherwise would. Colors observed during that period will appear to lack the color component detected by the desensitized photoreceptors. This effect is responsible for the phenomenon of afterimages, in which the eye may continue to see a bright figure after looking away from it, but in a complementary color.
After exposure to strong light in their sensitivity range, photoreceptors of a given type become desensitized. For a few seconds after the light ceases, they will continue to signal less strongly than they otherwise would. Colors observed during that period will appear to lack the color component detected by the desensitized photoreceptors. This effect is responsible for the phenomenon of afterimages, in which the eye may continue to see a bright figure after looking away from it, but in a complementary color.
Afterimage effects have also been utilized by artists, including Vincent van Gogh.
Color constancy - When an artist uses a limited color palette, the human eye tends to compensate by seeing any gray or neutral color as the color which is missing from the color wheel. For example, in a limited palette consisting of red, yellow, black, and white, a mixture of yellow and black will appear as a variety of green, a mixture of red and black will appear as a variety of purple, and pure gray will appear bluish.[15]
When an artist uses a limited color palette, the human eye tends to compensate by seeing any gray or neutral color as the color which is missing from the color wheel. For example, in a limited palette consisting of red, yellow, black, and white, a mixture of yellow and black will appear as a variety of green, a mixture of red and black will appear as a variety of purple, and pure gray will appear bluish.[15]
The trichromatic theory is strictly true when the visual system is in a fixed state of adaptation. In reality, the visual system is constantly adapting to changes in the environment and compares the various colors in a scene to reduce the effects of the illumination. If a scene is illuminated with one light, and then with another, as long as the difference between the light sources stays within a reasonable range, the colors in the scene appear relatively constant to us. This was studied by Edwin H. Land in the 1970s and led to his retinex theory of color constancy.
Both phenomena are readily explained and mathematically modeled with modern theories of chromatic adaptation and color appearance (e.g. CIECAM02, iCAM).[16] There is no need to dismiss the trichromatic theory of vision, but rather it can be enhanced with an understanding of how the visual system adapts to changes in the viewing environment.
Color naming - This picture contains one million pixels, each one a different color
This picture contains one million pixels, each one a different color
Colors vary in several different ways, including hue (shades of red, orange, yellow, green, blue, and violet), saturation, brightness, and gloss. Some color words are derived from the name of an object of that color, such as "orange" or "salmon", while others are abstract, like "red".
In the 1969 study Basic Color Terms: Their Universality and Evolution, Brent Berlin and Paul Kay describe a pattern in naming "basic" colors (like "red" but not "red-orange" or "dark red" or "blood red", which are "shades" of red). All languages that have two "basic" color names distinguish dark/cool colors from bright/warm colors. The next colors to be distinguished are usually red and then yellow or green. All languages with six "basic" colors include black, white, red, green, blue, and yellow. The pattern holds up to a set of twelve: black, gray, white, pink, red, orange, yellow, green, blue, purple, brown, and azure (distinct from blue in Russian and Italian, but not English).
In culture - Colors, their meanings and associations can play major role in works of art, including literature.[17]
Colors, their meanings and associations can play major role in works of art, including literature.[17]
Associations - Individual colors have a variety of cultural associations such as national colors (in general described in individual color articles and color symbolism). The field of color psychology attempts to identify the effects of color on human emotion and activity. Chromotherapy is a form of alternative medicine attributed to various Eastern traditions. Colors have different associations in different countries and cultures.[18]
Individual colors have a variety of cultural associations such as national colors (in general described in individual color articles and color symbolism). The field of color psychology attempts to identify the effects of color on human emotion and activity. Chromotherapy is a form of alternative medicine attributed to various Eastern traditions. Colors have different associations in different countries and cultures.[18]
Different colors have been demonstrated to have effects on cognition. For example, researchers at the University of Linz in Austria demonstrated that the color red significantly decreases cognitive functioning in men.[19]
Spectral colors and color reproduction - The CIE 1931 color space chromaticity diagram. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers. The colors depicted depend on the color space of the device on which you are viewing the image, and therefore may not be a strictly accurate representation of the color at a particular position, and especially not for monochromatic colors.
The CIE 1931 color space chromaticity diagram. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers. The colors depicted depend on the color space of the device on which you are viewing the image, and therefore may not be a strictly accurate representation of the color at a particular position, and especially not for monochromatic colors.
Most light sources are mixtures of various wavelengths of light. Many such sources can still effectively produce a spectral color, as the eye cannot distinguish them from single-wavelength sources. For example, most computer displays reproduce the spectral color orange as a combination of red and green light; it appears orange because the red and green are mixed in the right proportions to allow the eye's cones to respond the way they do to the spectral color orange.
A useful concept in understanding the perceived color of a non-monochromatic light source is the dominant wavelength, which identifies the single wavelength of light that produces a sensation most similar to the light source. Dominant wavelength is roughly akin to hue.
There are many color perceptions that by definition cannot be pure spectral colors due to desaturation or because they are purples (mixtures of red and violet light, from opposite ends of the spectrum). Some examples of necessarily non-spectral colors are the achromatic colors (black, gray, and white) and colors such as pink, tan, and magenta.
Two different light spectra that have the same effect on the three color receptors in the human eye will be perceived as the same color. They are metamers of that color. This is exemplified by the white light emitted by fluorescent lamps, which typically has a spectrum of a few narrow bands, while daylight has a continuous spectrum. The human eye cannot tell the difference between such light spectra just by looking into the light source, although reflected colors from objects can look different. (This is often exploited; for example, to make fruit or tomatoes look more intensely red.)
Similarly, most human color perceptions can be generated by a mixture of three colors called primaries. This is used to reproduce color scenes in photography, printing, television, and other media. There are a number of methods or color spaces for specifying a color in terms of three particular primary colors. Each method has its advantages and disadvantages depending on the particular application.
No mixture of colors, however, can produce a response truly identical to that of a spectral color, although one can get close, especially for the longer wavelengths, where the CIE 1931 color space chromaticity diagram has a nearly straight edge. For example, mixing green light (530 nm) and blue light (460 nm) produces cyan light that is slightly desaturated, because response of the red color receptor would be greater to the green and blue light in the mixture than it would be to a pure cyan light at 485 nm that has the same intensity as the mixture of blue and green.
Because of this, and because the primaries in color printing systems generally are not pure themselves, the colors reproduced are never perfectly saturated spectral colors, and so spectral colors cannot be matched exactly. However, natural scenes rarely contain fully saturated colors, thus such scenes can usually be approximated well by these systems. The range of colors that can be reproduced with a given color reproduction system is called the gamut. The CIE chromaticity diagram can be used to describe the gamut.
Another problem with color reproduction systems is connected with the acquisition devices, like cameras or scanners. The characteristics of the color sensors in the devices are often very far from the characteristics of the receptors in the human eye. In effect, acquisition of colors can be relatively poor if they have special, often very "jagged", spectra caused for example by unusual lighting of the photographed scene. A color reproduction system "tuned" to a human with normal color vision may give very inaccurate results for other observers.
The different color response of different devices can be problematic if not properly managed. For color information stored and transferred in digital form, color management techniques, such as those based on ICC profiles, can help to avoid distortions of the reproduced colors. Color management does not circumvent the gamut limitations of particular output devices, but can assist in finding good mapping of input colors into the gamut that can be reproduced.
Additive coloring - Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.
Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.
Additive color is light created by mixing together light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color systems such as projectors and computer terminals.
Subtractive coloring - Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black
Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black
Twelve main pigment colors - Subtractive coloring uses dyes, inks, pigments, or filters to absorb some wavelengths of light and not others. The color that a surface displays comes from the parts of the visible spectrum that are not absorbed and therefore remain visible. Without pigments or dye, fabric fibers, paint base and paper are usually made of particles that scatter white light (all colors) well in all directions. When a pigment or ink is added, wavelengths are absorbed or "subtracted" from white light, so light of another color reaches the eye.
Subtractive coloring uses dyes, inks, pigments, or filters to absorb some wavelengths of light and not others. The color that a surface displays comes from the parts of the visible spectrum that are not absorbed and therefore remain visible. Without pigments or dye, fabric fibers, paint base and paper are usually made of particles that scatter white light (all colors) well in all directions. When a pigment or ink is added, wavelengths are absorbed or "subtracted" from white light, so light of another color reaches the eye.
If the light is not a pure white source (the case of nearly all forms of artificial lighting), the resulting spectrum will appear a slightly different color. Red paint, viewed under blue light, may appear black. Red paint is red because it scatters only the red components of the spectrum. If red paint is illuminated by blue light, it will be absorbed by the red paint, creating the appearance of a black object.
Structural color - Structural colors are colors caused by interference effects rather than by pigments. Color effects are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the color's wavelength. If the microstructures are spaced randomly, light of shorter wavelengths will be scattered preferentially to produce Tyndall effect colors: the blue of the sky (Rayleigh scattering, caused by structures much smaller than the wavelength of light, in this case air molecules), the luster of opals, and the blue of human irises. If the microstructures are aligned in arrays, for example the array of pits in a CD, they behave as a diffraction grating: the grating reflects different wavelengths in different directions due to interference phenomena, separating mixed "white" light into light of different wavelengths. If the structure is one or more thin layers then it will reflect some wavelengths and transmit others, depending on the layers' thickness.
Structural colors are colors caused by interference effects rather than by pigments. Color effects are produced when a material is scored with fine parallel lines, formed of one or more parallel thin layers, or otherwise composed of microstructures on the scale of the color's wavelength. If the microstructures are spaced randomly, light of shorter wavelengths will be scattered preferentially to produce Tyndall effect colors: the blue of the sky (Rayleigh scattering, caused by structures much smaller than the wavelength of light, in this case air molecules), the luster of opals, and the blue of human irises. If the microstructures are aligned in arrays, for example the array of pits in a CD, they behave as a diffraction grating: the grating reflects different wavelengths in different directions due to interference phenomena, separating mixed "white" light into light of different wavelengths. If the structure is one or more thin layers then it will reflect some wavelengths and transmit others, depending on the layers' thickness.
Structural color is studied in the field of thin-film optics. The most ordered or the most changeable structural colors are iridescent. Structural color is responsible for the blues and greens of the feathers of many birds (the blue jay, for example), as well as certain butterfly wings and beetle shells. Variations in the pattern's spacing often give rise to an iridescent effect, as seen in peacock feathers, soap bubbles, films of oil, and mother of pearl, because the reflected color depends upon the viewing angle. Numerous scientists have carried out research in butterfly wings and beetle shells, including Isaac Newton and Robert Hooke. Since 1942, electron micrography has been used, advancing the development of products that exploit structural color, such as "photonic" cosmetics.[20]
Additional terms - Color wheel: an illustrative organization of color hues in a circle that shows relationships.
Color wheel: an illustrative organization of color hues in a circle that shows relationships.
Colorfulness, chroma, purity, or saturation: how "intense" or "concentrated" a color is. Technical definitions distinguish between colorfulness, chroma, and saturation as distinct perceptual attributes and include purity as a physical quantity. These terms, and others related to light and color are internationally agreed upon and published in the CIE Lighting Vocabulary.[21] More readily available texts on colorimetry also define and explain these terms.[16][22]
Dichromatism: a phenomenon where the hue is dependent on concentration and thickness of the absorbing substance.
References - ^ Wyszecki, Gnther; Stiles, W.S. (1982). Colour Science: Concepts and Methods, Quantitative Data and Formulae (2nd ed.). New York: Wiley Series in Pure and Applied Optics. ISBN 978-0-471-02106-3.
^ Wyszecki, Gnther; Stiles, W.S. (1982). Colour Science: Concepts and Methods, Quantitative Data and Formulae (2nd ed.). New York: Wiley Series in Pure and Applied Optics. ISBN 978-0-471-02106-3.
^ Pastoureau, Michael (2008). Black: The History of a Color. Princeton University Press. p. 216. ISBN 978-0691139302.
^ a b Judd, Deane B.; Wyszecki, Gnter (1975). Color in Business, Science and Industry. Wiley Series in Pure and Applied Optics (third ed.). New York: Wiley-Interscience. p. 388. ISBN 978-0-471-45212-6.
^ Hermann von Helmholtz, Physiological Optics: The Sensations of Vision, 1866, as translated in Sources of Color Science, David L. MacAdam, ed., Cambridge: MIT Press, 1970.
^ Palmer, S.E. (1999). Vision Science: Photons to Phenomenology, Cambridge, MA: MIT Press. ISBN 0-262-16183-4.
^ Gnambs, Timo; Appel, Markus; Batinic, Bernad (2010). "Color red in web-based knowledge testing". Computers in Human Behavior. 26 (6): 162531. doi:10.1016/j.chb.2010.06.010.
External links - ColorLab MATLAB toolbox for color science computation and accurate color reproduction (by Jesus Malo and Maria Jose Luque, Universitat de Valencia). It includes CIE standard tristimulus colorimetry and transformations to a number of non-linear color appearance models (CIE Lab, CIE CAM, etc.).
ColorLab MATLAB toolbox for color science computation and accurate color reproduction (by Jesus Malo and Maria Jose Luque, Universitat de Valencia). It includes CIE standard tristimulus colorimetry and transformations to a number of non-linear color appearance models (CIE Lab, CIE CAM, etc.).
a useful or valuable thing or person. - an item of property owned by a person or company, regarded as having value and available to meet debts, commitments, or legacies.
an item of property owned by a person or company, regarded as having value and available to meet debts, commitments, or legacies.
The act or process of classifying - systematic arrangement in groups or categories according to established criteria
systematic arrangement in groups or categories according to established criteria
CLASS, CATEGORY -
constituent construction product is: A manufacturer specific construction product (i.e. with a manufacturer reference number) that is not specified by the designer or selected by the constructor, but is used in the manufacture of a specified construction product.
something positioned within a larger object -
Classification, an introduction describes classification as, `what things are called, and how those names are arranged and structured', or `the act or process of dividing things into groups according to their type.'
In the construction industry, classification is used in:
Specifications. - Production information.
Production information. - Libraries.
Libraries. - Drawings.
Drawings. - Schedules of rates / quantities.
Schedules of rates / quantities. - Information management systems.
Information management systems. - Operation and maintenance information.
Operation and maintenance information. - The OmniClass Construction Classification System, also known as OmniClass(TM) or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
The OmniClass Construction Classification System, also known as OmniClass(TM) or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
It covers the full facility lifecycle from conception to demolition or reuse, and all types of construction in the built environment. It is useful for Building Information Modelling (BIM), organising reports and object libraries.
Similar to Uniclass, OmniClass is derived from internationally-accepted standards developed by the International Organisation for Standardisation (ISO) and the International Construction Information Society (ICIS) and has been developed from the early-1990s to the present.
OmniClass comprises 15 tables, some of which focus on buildings and landscapes, and some of which also serve civil and/or process engineering. Each table can be used independently to classify a particular type of information, or entries on it can be combined with entries on other tables to classify more complex subjects.
The tables are as follows: -
Construction Entities by Function - Table 11. - Construction Entities by Form - Table 12.
Construction Entities by Form - Table 12. - Spaces by Function - Table 13.
Spaces by Function - Table 13. - Spaces by Form - Table 14.
Spaces by Form - Table 14. - Elements (includes Designed Elements) - Table 21.
Elements (includes Designed Elements) - Table 21.
Work Results - Table 22. - Products - Table 23.
Products - Table 23. - Phases - Table 31.
Phases - Table 31. - Services - Table 32.
Services - Table 32. - Disciplines - Table 33.
Disciplines - Table 33. - Organisational Roles - Table 34.
Organisational Roles - Table 34. - Tools - Table 35.
Tools - Table 35. - Information - Table 36.
Information - Table 36. - Materials - Table 41.
Materials - Table 41. - Properties - Table 49.
Properties - Table 49. - OmniClass incorporates other extant systems currently in use, such as; MasterFormat(TM) for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
OmniClass incorporates other extant systems currently in use, such as; MasterFormat(TM) for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
Projects, by definition, have a beginning and an end. They also have defined phases between the project kickoff and project closeout. A phase represents a grouping of similar activities that has a very loosely defined beginning and end. Phases are also typically sequential, where the prior phase is essentially complete before the beginning of the next phase. Phases do not have clear-cut end dates and some activities in an early phase of the project will continue into the later phases. This is in contrast to project beginning and ending dates and milestone dates, which do have clearly defined dates with the expectation that these dates will be met.
A rigid link is a type of connection that connects geometric entities such as surfaces, curves, and points so that they remain rigidly connected during an analysis.
window inset The inset of the window into the wall.
Wall Closure This parameter sets the layer wrapping around the window. It overrides any settings in the host.
Glass Pane Material The material for the glass panes in the window.
Assembly code Uniformat assembly code selected from hierarchical list.
OmniClass Number The number from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
OmniClass Title The name from Table 23 of the OmniClass Construction Classification System that best categorizes the family type.
Operation The operation of the window, as defined by the current IFC description (for example, single_panel or triple_panel_horizontal). These values are case-insensitive, and underscores are optional. (SINGLE_PANEL and SinglePanel are the same.)
Heat Transfer Coefficient (U) Used in calculating the heat transfer, typically by convection or phase change between a fluid and a solid.
Keynote Add or edit the window keynote. Click in the value box to open the Keynotes dialog. See Keynotes.
Manufacturer The manufacturer of the window. - URL The link to the manufacturer's web page.
URL The link to the manufacturer's web page.
A work plane is a virtual 2-dimensional surface used as the origin for a view or for sketching elements.
An architectural drawing or architect's drawing is a technical drawing of a building (or building project) that falls within the definition of architecture. Architectural drawings are used by architects and others for a number of purposes: to develop a design idea into a coherent proposal, to communicate ideas and concepts, to convince clients of the merits of a design, to assist a building contractor to construct it based on design intent, as a record of the design and planned development, or to make a record of a building that already exists.
Architectural drawings are made according to a set of conventions, which include particular views (floor plan, section etc.), sheet sizes, units of measurement and scales, annotation and cross referencing.
Historically, drawings were made in ink on paper or a similar material, and any copies required had to be laboriously made by hand. The twentieth century saw a shift to drawing on tracing paper, so that mechanical copies could be run off efficiently. The development of the computer had a major impact on the methods used to design and create technical drawings,[1] making manual drawing almost obsolete, and opening up new possibilities of form using organic shapes and complex geometry. Today the vast majority of drawings are created using CAD software.[2]
The size of drawings reflects the materials available and the size that is convenient to transport rolled up or folded, laid out on a table, or pinned up on a wall. The drafting process may impose limitations on the size that is realistically workable. Sizes are determined by a consistent paper size system, according to local usage. Normally the largest paper size used in modern architectural practice is ISO A0 (841 mm 1,189 mm or 33.1 in 46.8 in) or in the USA Arch E (762 mm 1,067 mm or 30 in 42 in) or Large E size (915 mm 1,220 mm or 36 in 48 in).[3]
Architectural drawings are drawn to scale, so that relative sizes are correctly represented. The scale is chosen both to ensure the whole building will fit on the chosen sheet size, and to show the required amount of detail. At the scale of one eighth of an inch to one foot (1:96) or the metric equivalent 1 to 100, walls are typically shown as simple outlines corresponding to the overall thickness. At a larger scale, half an inch to one foot (1:24) or the nearest common metric equivalent 1 to 20, the layers of different materials that make up the wall construction are shown. Construction details are drawn to a larger scale, in some cases full size (1 to 1 scale).
Scale drawings enable dimensions to be "read" off the drawing, i.e. measured directly. Imperial scales (feet and inches) are equally readable using an ordinary ruler. On a one-eighth inch to one foot scale drawing, the one-eighth divisions on the ruler can be read off as feet. Architects normally use a scale ruler with different scales marked on each edge. A third method, used by builders in estimating, is to measure directly off the drawing and multiply by the scale factor.
Dimensions can be measured off drawings made on a stable medium such as vellum. All processes of reproduction introduce small errors, especially now that different copying methods mean that the same drawing may be re-copied, or copies made in several different ways. Consequently, dimensions need to be written ("figured") on the drawing. The disclaimer "Do not scale off dimensions" is commonly inscribed on architects drawings, to guard against errors arising in the copying process.
Standard views used in architectural drawing[edit]
This section deals with the conventional views used to represent a building or structure. See the Types of architectural drawing section below for drawings classified according to their purpose.
Principal floor plans of the Queen's House, Greenwich (UK).
A floor plan is the most fundamental architectural diagram, a view from above showing the arrangement of spaces in building in the same way as a map, but showing the arrangement at a particular level of a building. Technically it is a horizontal section cut through a building (conventionally at four feet / one metre and twenty centimetres above floor level), showing walls, windows and door openings and other features at that level. The plan view includes anything that could be seen below that level: the floor, stairs (but only up to the plan level), fittings and sometimes furniture. Objects above the plan level (e.g. beams overhead) can be indicated as dashed lines.
Geometrically, plan view is defined as a vertical orthographic projection of an object on to a horizontal plane, with the horizontal plane cutting through the building.
A site plan is a specific type of plan, showing the whole context of a building or group of buildings. A site plan shows property boundaries and means of access to the site, and nearby structures if they are relevant to the design. For a development on an urban site, the site plan may need to show adjoining streets to demonstrate how the design fits into the urban fabric. Within the site boundary, the site plan gives an overview of the entire scope of work. It shows the buildings (if any) already existing and those that are proposed, usually as a building footprint; roads, parking lots, footpaths, hard landscaping, trees and planting. For a construction project, the site plan also needs to show all the services connections: drainage and sewer lines, water supply, electrical and communications cables, exterior lighting etc.
Site plans are commonly used to represent a building proposal prior to detailed design: drawing up a site plan is a tool for deciding both the site layout and the size and orientation of proposed new buildings. A site plan is used to verify that a proposal complies with local development codes, including restrictions on historical sites. In this context the site plan forms part of a legal agreement, and there may be a requirement for it to be drawn up by a licensed professional: architect, engineer, landscape architect or land surveyor.[4]
An elevation is a view of a building seen from one side, a flat representation of one faade. This is the most common view used to describe the external appearance of a building. Each elevation is labelled in relation to the compass direction it faces, e.g. looking toward the north you would be seeing the southern elevation of the building.[5] Buildings are rarely a simple rectangular shape in plan, so a typical elevation may show all the parts of the building that are seen from a particular direction.
Geometrically, an elevation is a horizontal orthographic projection of a building onto a vertical plane, the vertical plane normally being parallel to one side of the building.
Architects also use the word elevation as a synonym for faade, so the "north elevation" is the north-facing wall of the building.
A cross-section, also simply called a section, represents a vertical plane cut through the object, in the same way as a floor plan is a horizontal section viewed from the top. In the section view, everything cut by the section plane is shown as a bold line, often with a solid fill to show objects that are cut through, and anything seen beyond generally shown in a thinner line. Sections are used to describe the relationship between different levels of a building. In the Observatorium drawing illustrated here, the section shows the dome which can be seen from the outside, a second dome that can only be seen inside the building, and the way the space between the two accommodates a large astronomical telescope: relationships that would be difficult to understand from plans alone.
A sectional elevation is a combination of a cross section, with elevations of other parts of the building seen beyond the section plane.
Geometrically, a cross section is a horizontal orthographic projection of a building on to a vertical plane, with the vertical plane cutting through the building.
Isometric and axonometric projections are a simple way of representing a three dimensional object, keeping the elements to scale and showing the relationship between several sides of the same object, so that the complexities of a shape can be clearly understood.
There is some confusion over the distinction between the terms isometric and axonometric. "Axonometric is a word that has been used by architects for hundreds of years. Engineers use the word axonometric as a generic term to include isometric, diametric and trimetric drawings."[6] This article uses the terms in the architecture-specific sense.
Despite fairly complex geometrical explanations, for the purposes of practical drafting the difference between isometric and axonometric is simple (see diagram above). In both, the plan is drawn on a skewed or rotated grid, and the verticals are projected vertically on the page. All lines are drawn to scale so that relationships between elements are accurate. In many cases a different scale is required for different axes, and again this can be calculated but in practice was often simply estimated by eye.
An isometric uses a plan grid at 30 degrees from the horizontal in both directions, which distorts the plan shape. Isometric graph paper can be used to construct this kind of drawing. This view is useful to explain construction details (e.g. three dimensional joints in joinery). The isometric was the standard view until the mid twentieth century, remaining popular until the 1970s, especially for textbook diagrams and illustrations.[7][8]
Cabinet projection is similar, but only one axis is skewed, the others being horizontal and vertical. Originally used in cabinet making, the advantage is that a principal side (e.g. a cabinet front) is displayed without distortion, so only the less important sides are skewed. The lines leading away from the eye are drawn at a reduced scale to lessen the degree of distortion. The cabinet projection is seen in Victorian engraved advertisements and architectural textbooks,[7] but has virtually disappeared from general use.
An axonometric uses a 45 degree plan grid, which keeps the original orthogonal geometry of the plan. The great advantage of this view for architecture is that the draftsman can work directly from a plan, without having to reconstruct it on a skewed grid. In theory the plan should be set at 45 degrees, but this introduces confusing coincidences where opposite corners align. Unwanted effects can be avoided by rotating the plan while still projecting vertically. This is sometimes called a planometric or plan oblique view,[9] and allows freedom to choose any suitable angle to present the most useful view of an object.
Traditional drafting techniques used 3060 and 45 degree set squares, and that determined the angles used in these views. Once the adjustable square became common those limitations were lifted.
The axonometric gained in popularity in the twentieth century, not just as a convenient diagram but as a formal presentation technique, adopted in particular by the Modern Movement.[6] Axonometric drawings feature prominently in the influential 1970's drawings of Michael Graves, James Stirling and others, using not only straightforward views but worms-eye view, unusually and exaggerated rotations of the plan, and exploded elements.[10]
The axonometric view is not readily generated by CAD programmes which create views from a three dimensional model. Consequently, it is now rarely used.
Detail drawings show a small part of the construction at a larger scale, to show how the component parts fit together. They are also used to show small surface details, for example decorative elements. Section drawings at large scale are a standard way of showing building construction details, typically showing complex junctions (such as floor to wall junction, window openings, eaves and roof apex) that cannot be clearly shown on a drawing that includes the full height of the building. A full set of construction details needs to show plan details as well as vertical section details. One detail is seldom produced in isolation: a set of details shows the information needed to understand the construction in three dimensions. Typical scales for details are 1/10, 1/5 and full size.
In traditional construction, many details were so fully standardised, that few detail drawings were required to construct a building. For example, the construction of a sash window would be left to the carpenter, who would fully understand what was required, but unique decorative details of the facade would be drawn up in detail. In contrast, modern buildings need to be fully detailed because of the proliferation of different products, methods and possible solutions.
Perspective in the manner of the classic Ideal city by Jean-Max Albert,1977.
Two point perspective, interior of Dercy House by Robert Adam, 1777.
Perspective in drawing is an approximate representation on a flat surface of an image as it is perceived by the eye. The key concepts here are:
Perspective is the view from a particular fixed viewpoint.
Horizontal and vertical edges in the object are represented by horizontals and verticals in the drawing.
Lines leading away into the distance appear to converge at a vanishing point.
All horizontals converge to a point on the horizon, which is a horizontal line at eye level.
Verticals converge to a point either above or below the horizon.
The basic categorization of artificial perspective is by the number of vanishing points:
One-point perspective where objects facing the viewer are orthogonal, and receding lines converge to a single vanishing point.
Two-point perspective reduces distortion by viewing objects at an angle, with all the horizontal lines receding to one of two vanishing points, both located on the horizon.
Three-point perspective introduces additional realism by making the verticals recede to a third vanishing point, which is above or below depending upon whether the view is seen from above or below.
The normal convention in architectural perspective is to use two-point perspective, with all the verticals drawn as verticals on the page.
Three-point perspective gives a casual, photographic snapshot effect. In professional architectural photography, conversely, a view camera or a perspective control lens is used to eliminate the third vanishing point, so that all the verticals are vertical on the photograph, as with the perspective convention. This can also be done by digital manipulation of a photograph taken with a standard lens.
Aerial perspective is a technique in painting, for indicating distance by approximating the effect of the atmosphere on distant objects. In daylight, as an ordinary object gets further from the eye, its contrast with the background is reduced, its colour saturation is reduced, and its colour becomes more blue. Not to be confused with aerial view or bird's eye view, which is the view as seen (or imagined) from a high vantage point. In J M Gandy's perspective of the Bank of England (see illustration at the beginning of this article), Gandy portrayed the building as a picturesque ruin in order to show the internal plan arrangement, a precursor of the cutaway view.[11]
A montage image is produced by superimposing a perspective image of a building on to a photographic background. Care is needed to record the position from which the photograph was taken, and to generate the perspective using the same viewpoint. This technique is popular in computer visualisation, where the building can be photorealistically rendered, and the final image is intended to be almost indistinguishable from a photograph.
A sketch is a rapidly executed freehand drawing, a quick way to record and develop an idea, not intended as a finished work. A diagram could also be drawn freehand but deals with symbols, to develop the logic of a design. Both can be worked up into a more presentable form and used to communicate the principles of a design.[citation needed]
In architecture, the finished work is expensive and time consuming, so it is important to resolve the design as fully as possible before construction work begins. Complex modern buildings involve a large team of different specialist disciplines, and communication at the early design stages is essential to keep the design moving towards a coordinated outcome.[12] Architects (and other designers) start investigating a new design with sketches and diagrams, to develop a rough design that provides an adequate response to the particular design problems.
There are two basic elements to a building design, the aesthetic and the practical. The aesthetic element includes the layout and visual appearance, the anticipated feel of the materials, and cultural references that will influence the way people perceive the building. Practical concerns include space allocated for different activities, how people enter and move around the building, daylight and artificial lighting, acoustics, traffic noise, legal matters and building codes, and many other issues. While both aspects are partly a matter of customary practice, every site is different. Many architects actively seek innovation, thereby increasing the number of problems to be resolved.
Architectural legend often refers to designs made on the back of an envelope or on a napkin.[13] Initial thoughts are important, even if they have to be discarded along the way, because they provide the central idea around which the design can develop.[14] Although a sketch is inaccurate, it is disposable and allows for freedom of thought, for trying different ideas quickly. Choice becomes sharply reduced once the design is committed to a scale drawing, and the sketch stage is almost always essential.
Diagrams are mainly used to resolve practical matters. In the early phases of the design architects use diagrams to develop, explore, and communicate ideas and solutions. They are essential tools for thinking, problem solving, and communication in the design disciplines. Diagrams can be used to resolve spatial relationships, but they can also represent forces and flows, e.g. the forces of sun and wind, or the flows of people and materials through a building.[15]
An exploded view diagram shows component parts dis-assembled in some way, so that each can be seen on its own. These views are common in technical manuals, but are also used in architecture, either in conceptual diagrams or to illustrate technical details. In a cutaway view parts of the exterior are omitted to show the interior, or details of internal construction.[16] Although common in technical illustration, including many building products and systems, the cutaway is in fact little-used in architectural drawing.
Architectural drawings are produced for a specific purpose, and can be classified accordingly. Several elements are often included on the same sheet, for example a sheet showing a plan together with the principal faade.
Drawings intended to explain a scheme and to promote its merits. Working drawings may include tones or hatches to emphasise different materials, but they are diagrams, not intended to appear realistic. Basic presentation drawings typically include people, vehicles and trees, taken from a library of such images, and are otherwise very similar in style to working drawings. Rendering is the art of adding surface textures and shadows to show the visual qualities of a building more realistically. An architectural illustrator or graphic designer may be employed to prepare specialist presentation images, usually perspectives or highly finished site plans, floor plans and elevations etc.
Measured drawings of existing land, structures and buildings. Architects need an accurate set of survey drawings as a basis for their working drawings, to establish exact dimensions for the construction work. Surveys are usually measured and drawn up by specialist land surveyors.
Historically, architects have made record drawings in order to understand and emulate the great architecture known to them. In the Renaissance, architects from all over Europe studied and recorded the remains of the Roman and Greek civilizations, and used these influences to develop the architecture of the period. Records are made both individually, for local purposes, and on a large scale for publication. Historic surveys worth referring to include:
Colen Campbell's Vitruvius Brittanicus, illustrations of English buildings by Inigo Jones and Sir Christopher Wren, as well as Campbell himself and other prominent architects of the era.
Historic American Buildings Survey, records of notable buildings drawn up during the 1930s Depression, this collection is held by the Library of Congress and is available copyright-free on the internet.
Record drawings are also used in construction projects, where "as-built" conditions of the completed building are documented to take account of all the variations made during the course of construction.
A comprehensive set of drawings used in a building construction project: these will include not only architect's drawings, but structural and other engineering drawings as well. Working drawings logically subdivide into location, assembly and component drawings.[9]
Location drawings, also called general arrangement drawings, include floor plans, sections and elevations: they show where the construction elements are located.
Assembly drawings show how the different parts are put together. For example, a wall detail will show the layers that make up the construction, how they are fixed to structural elements, how to finish the edges of openings, and how prefabricated components are to be fitted.
Component drawings enable self-contained elements e.g. windows and doorsets, to be fabricated in a workshop, and delivered to site complete and ready for installation. Larger components may include roof trusses, cladding panels, cupboards and kitchens. Complete rooms, especially hotel bedrooms and bathrooms, may be made as prefabricated pods complete with internal decorations and fittings.
Formerly, working drawings would typically combine plans, sections, elevations and some details to provide a complete explanation of a building on one sheet. That was possible because little detail was included, the building techniques involved being common knowledge amongst building professionals. Modern working drawings are much more detailed and it is standard practice to isolate select areas of the project on separate sheets. Notes included on drawings are brief, referring to standardised specification documents for more information. Understanding the layout and construction of a modern building involves studying an often-sizeable set of drawings and documents.
Until the latter part of the 20th century, all architectural drawings were manually produced, if not by the architects, then by trained (but less skilled) draftsmen (or drafters), who did not generate the design, but did make many of the less important decisions. This system has continued with CAD drafting: many design architects have little or no knowledge of CAD software programmes, relying upon others to take their designs beyond the sketch stage. Draftsmen often specialize in a type of structure, such as residential or commercial, or in a type of construction: timber frame, reinforced concrete, prefabrication, etc.[17]
The traditional tools of the architect were the drawing board or drafting table, T-square and set squares, protractor, compasses, pencil, and drawing pens of different types.[14] Drawings were made on vellum, coated linen, and tracing paper. Lettering would either be done by hand, mechanically using a stencil, or a combination of the two. Ink lines were drawn with a ruling pen, a relatively sophisticated device similar to a dip-in pen, but with adjustable line width, capable of producing a very fine controlled line width. Ink pens had to be dipped into ink frequently. Draftsmen worked standing up, keeping the ink on a separate table to avoid spilling ink on the drawing.[citation needed]
Developments in the 20th century included the parallel motion drawing board, as well as more complex improvements on the basic T-square. The development of reliable technical drawing pens allowed for faster drafting and stencilled lettering. Letraset dry transfer lettering and half-tone sheets were popular from the 1970s until[when?] computers made those processes obsolete.[citation needed]
Computer generated perspective of the Moscow School of Management, by David Adjaye.
Computer-aided design (generally referred to by the acronym CAD) is the use of computer software to create drawings. Today the vast majority of technical drawings of all kinds are made using CAD. Instead of drawing lines on paper, the computer records equivalent information electronically. There are many advantages to this system: repetition is reduced because complex elements can be copied, duplicated and stored for re-use. Errors can be deleted, and the speed of drafting allows many permutations to be tried before the design is finalised. On the other hand, CAD drawing encourages a proliferation of detail and increased expectations of accuracy, aspects which reduce the efficiency originally expected from the move to computerisation.[citation needed]
Professional CAD software such as AutoCAD is complex and requires both training and experience before the operator becomes fully productive. Consequently, skilled CAD operators are often divorced from the design process. Simpler software such as SketchUp and Vectorworks allows for more intuitive drawing and is intended as a design tool.[18][19]
CAD is used to create all kinds of drawings, from working drawings to photorealistic perspective views. Architectural renderings (also called visualisations) are made by creating a three-dimensional model using CAD. The model can be viewed from any direction to find the most useful viewpoints. Different software (for example Autodesk 3ds Max) is then used to apply colour and texture to surfaces, and to represent shadows and reflections. The result can be accurately combined with photographic elements: people, cars, background landscape.[citation needed]
Building information modeling (BIM) is the logical development of CAD drawing, a relatively new technology but fast becoming mainstream. The design team collaborates to create a three-dimensional computer model, and all plans and other two-dimensional views are generated directly from the model, ensuring spatial consistency. The key innovation here is to share the model via the internet, so that all the design functions (site survey, architecture, structure and services) can be integrated into a single model, or as a series of models associated with each specialism that are shared throughout the design development process. Some form of management, not necessarily by the architect, needs to be in place to resolve conflicting priorities. The starting point of BIM is spatial design, but it also enables components to be quantified and scheduled directly from the information embedded in the model.[citation needed]. Building information modelling can be characterized into 3 different levels ranging from 0-3. These levels represent BIM maturity and distinguishes the amount of cooperation in projects. They gauge information being shared throughout the whole process.
Level 0 is individualized with no collaboration. Individuals are working on their own CAD files separately and working using their own standards. These are known to be more traditional ways which are being phased out therefore no longer being used today.
Level 1 is a mixture of 3D and 2D work. Project teams are required to manage and share data amongst the team. Aspects such as naming conventions should be adopted.
Level 2 involves all team members using 3D models.Although they might not being using the same information, the built environment is shared through a similar file formats. This level also introduces construction sequencing and cost.
Level 3 involves working on a shared project model. The model exists in a central environment and can be modified by everyone. Conflicting information is reduced due to real time update on models. Later levels include sequencing components,cost estimation and accounting for upfront costs.
Parametric design is an example of computer intelligence rising in the field of architecture. It is the creation of complex relationships between models. Measurements in parametric design connect by scripts. Users can adjust and adapt their models based on measurements. Changing one measurement will affect other measurements based on the set parameters. The parametric design uses scalability and adjustments which involve complex organic shapes. It allows for the creation of forms that would not be possible with regular 3d modeling or would take copious amounts of time. Models can decrease production time, therefore, allowing for the time allotted to other times of the design process. An argument with parametric design is the question of practicality. At times, it is unsure whether or not these styles properly comply with users wants and needs.[20] Real-life examples of parametric designs would be The Metropol Parasol in Seville or the Canton in Guangzhou China. These forms have a commonality with complex repetitive patterns which twist, bend and curve in dramatic ways. These lattices are unique and there is a complexity tied with how they look. This is coined as parametricism by Zaha Hadid which is a style based on digital animation techniques.
An architectural animation is a short film showing how a proposed building will look: the moving image makes three-dimensional forms much easier to understand. An animation is generated from a series of hundreds or even thousands of still images, each made in the same way as an architectural visualization. A computer-generated building is created using a CAD programs, and that is used to create more or less realistic views from a sequence of viewpoints. The simplest animations use a moving viewpoint, while more complex animations can include moving objects: people, vehicles, and so on.[citation needed]
Schools are producing well versed architecture students who perform in computer assisted collaboration, construction automation and intelligent buildings which promise to have as much impact before the adaptation of technologies. Its important to understand that architects are problem solvers and critical thinking which has been used since the dawn of man is still being carried on. The idea of innovation,responsiveness and critical thinking will never be phased out and always relevant today. Although pure drafting, which involves manually drawing plans for construction, are not being used as often because of CAD, they are training architects to exercise human centered designer and to dive deeper into the culture to ultimately understand clientele . Human centered design involves the human perspective in all steps of the design process .The unpredictability and complexity of humans are unmatched with any pre-programmed systems.
Virtual reality in architectural projects helps designers understand spaces from a cognitive perspective.[21] VR stands for virtual reality and explains an experience in a world that doesn't exist. Virtual reality creates an experience generated by a computer program. The use of motion tracking allows for quick manipulation. It creates an individual secluded experience. Architecture firms are using this as a tool to allow employees to learn and create a more engaging experience for both clients and employees. Benefits of VR for architecture include low start-up costs, gaining a competitive edge, avoiding revision, and the duplication of real-world scenarios. By placing a client into the virtual world, the feedback is often more straight forward as the client can walk through based on their needs and aesthetic choices.
Due to COVID-19. architecture firms have increasingly shifted to a digital environment for collaboration. Video conferencing is proving to be a popular way of meeting with clients and simulating the studio environment. Collaboration and communication using programs like Zoom are common consistently being used. Since the beginning of the epidemic, people are expected to be increasingly well versed with technology. Although coordination is often difficult, programs like BIM help improve workflow between both architects clients. However, relationships with clients are harder to facilitate because clients are not able to touch or feel the work.[22] Adaptation is critical as more and more programs are being implemented among the studio to support staff.
Reprographics or reprography covers a variety of technologies, media, and support services used to make multiple copies of original drawings. Prints of architectural drawings are still sometimes called blueprints, after one of the early processes which produced a white line on blue paper. The process was superseded by the dye-line print system which prints black on white coated paper (Whiteprint). The standard modern processes are the ink-jet printer, laser printer and photocopier, of which the ink-jet and laser printers are commonly used for large-format printing. Although colour printing is now commonplace, it remains expensive above A3 size, and architect's working drawings still tend to adhere to the black and white / greyscale aesthetic.
^ David Byrnes, AutoCAD 2008 For Dummies. Publisher: John Wiley & Sons; illustrated edition (4 May 2007). ISBN 0-470-11650-1
^ Ching, Frank (1985), Architectural Graphics Second Edition, New York: Van Norstrand Reinhold, ISBN 0-442-21862-1
^ a b Alan Piper, Drawing for Designers. Laurence King Publishing 2007. ISBN 978-1-85669-533-6 Page 57, definition of axonometric drawing
^ a b W. B. McKay: McKay's Building Construction. Donhead Publishing 2005. ISBN 978-1-873394-72-4 A new reprint of the combined three volumes that McKay published between 1938 and 1944. Heavily illustrated textbook of architectural detailing.
^ a b Arthur Thompson, Architectural Design Procedures, Second Edition. Architectural Press: Elsevier 2007. ISBN 978-0-340-71941-1
^ Thomas W Schaller, Architecture in Watercolour. Van Nostrand Re9inhold, New York 1990. ISBN 0-442-23484-8
^ The Great Perspectivists, by Gavin Stamp. RIBA Drawings Series, published by Trefoil Books London 1982. ISBN 0-86294-002-8
^ Richard Boland and Fred Collopy (2004). Managing as designing. p.69.
^ a b Rendow Yee (2002). Architectural Drawing: A Visual Compendium of Types and Methods. 2nd Edition. Wiley, 2002.
^ Andreas C. Papadakis (1988). Deconstruction in Architecture: In Architecture and Urbanism. p.65.
Asset - PAS 1192-3 Specification for information management for the operational phase of construction projects using building information modelling, is concerned with the operational phase of built assets, specifying how an asset information model should be created used and maintained through the life an asset.
PAS 1192-3 Specification for information management for the operational phase of construction projects using building information modelling, is concerned with the operational phase of built assets, specifying how an asset information model should be created used and maintained through the life an asset.
It defines an asset as an item, thing or entity that has potential or actual value to an organisation
And suggests that an asset may be fixed, mobile or movable. It may be an individual item of plant, a system of connected equipment, a space within a structure, a piece of land, or an entire piece of infrastructure or an entire building or portfolio of assets.
It suggests that, in this context, value can be tangible, intangible, financial or non-financial and can vary throughout the life of the asset.
This is narrower than the description of the term asset in PAS 55-1:2008 Asset Management Part 1: Specification for the optimised management of physical assets (now withdrawn) which identified five types of asset:
Human assets. - Information assets.
Information assets. - Intangible assets.
Intangible assets. - Financial assets.
Financial assets. - Physical assets.
Physical assets. - It proposed that physical assets include plant, machinery, property, vehicles and other items that have a distinct value to the organisation, including .any software code that is critical to the delivery function of the asset.
It proposed that physical assets include plant, machinery, property, vehicles and other items that have a distinct value to the organisation, including .any software code that is critical to the delivery function of the asset.
The February 2015 draft of PAS 1192-5:2015, Specification for security-minded building information modelling, digital built environments and smart asset management, defines a 'built asset' as a:
...building, multiple buildings (e.g. a site or campus) or built infrastructure (e.g. roads, railways, pipelines, dams, docks, etc.) that are the subject of a construction project or where the asset information is held in a digital format.
According to NRM3: Order of cost estimating and cost planning for building maintenance works, the term asset refers to:
'...the whole building, element, system, sub-element and/or a specific asset, or component or part thereof. Note asset classifications can be at portfolio/estate level (e.g. offices or schools) down to specific maintainable assets (e.g. boilers). NRM 3 applies to all levels of building or constructed assets that are applicable to maintenance and life cycle major repairs and replacement work.'
The Loss Prevention Standard (LSP 2082 : Issue 1.0), published by BRE Global in 2017, defines an asset as: An item, thing or entity that has potential or actual value to an organisation. The value may be derived financially or due to the asset being critical to the organisations mission.
See also: Tangible v intangible assets. -
OmniClass is a comprehensive classification system for the construction industry. OmniClass can be used for many applications, such as filing physical materials or organizing project information, but its chief application is to provide a classification structure for electronic databases and software, enriching the information used in those resources. OmniClass incorporates other extant systems currently in use as the basis of two of its Tables MasterFormat for Table 22 - Work Results and UniFormat for Table 21 - Elements.
OmniClass provides a method for classifying the full built environment through the full project life cycle.
Beam Analysis Properties - Help
Help - Modify the analytical properties of the beam to accommodate structural analysis tools and procedures.
Modify the analytical properties of the beam to accommodate structural analysis tools and procedures.
To change structural analytical properties, select the element. In the Properties palette, select the element specific analytical properties from the Properties filter.
Name - Description
Description - Analytical Model
Analytical Model - Analyze as
Analyze as - Used by external analysis applications to determine whether beam conditions contribute to Gravity or Lateral analysis.
Used by external analysis applications to determine whether beam conditions contribute to Gravity or Lateral analysis.
Analytical Links - Either Yes, No, or From Column. A frame element that can be set to fully rigid or released in global directions. When Analytical Links are enabled, an additional analytical segment is engaged in the model between the end of the analytical model of a beam and the analytical model of a column. From Column defines the analytical link of the beam to that of its connected column.
Either Yes, No, or From Column. A frame element that can be set to fully rigid or released in global directions. When Analytical Links are enabled, an additional analytical segment is engaged in the model between the end of the analytical model of a beam and the analytical model of a column. From Column defines the analytical link of the beam to that of its connected column.
Applies to curved beams only. Select to create segment based on both the values for Maximum discretized offset and Use hard-points. See Segmented Analytical Model Parameters.
Maximum discretized offset - Applies to curved beams only. Limits the distance between a smooth curve and a line segment when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Applies to curved beams only. Limits the distance between a smooth curve and a line segment when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Use hard-points - Applies to curved beams only. Forces the segmented analytical model to have nodal points at the ends of the members attached to the curved beam when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Applies to curved beams only. Forces the segmented analytical model to have nodal points at the ends of the members attached to the curved beam when the Approximate curve parameter is selected. See Segmented Analytical Model Parameters.
Analytical Properties - Family Type
Family Type - The family type of the element.
The family type of the element. - Physical Material Asset
Physical Material Asset - The name of a physical asset assigned to the beam material (read-only).
The name of a physical asset assigned to the beam material (read-only).
Length - The length of the analytical model.
The length of the analytical model. - Cross-Section Rotation
Cross-Section Rotation - Start Release - Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Start Release - Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Displays the cross-section rotation of analytical members. The angle of rotation is measured from the work plane of the member and the direction of the center reference plane.
Analytical Alignment - Start Alignment Method
Start Alignment Method - Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam start position are automatically justified or have a defined projection.
Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam start position are automatically justified or have a defined projection.
Start y Projection - Either Location Line, Left of Element, Center of Element, Right of Element, , or . Available when Start Alignment Method is specified as Projection.
Either Location Line, Left of Element, Center of Element, Right of Element,
Specifies the horizontal location of the analytical model at the start of the beam.
Start z Projection - Either Location Line, Top of Element, Center of Element, Bottom of Element, , , or . Available when Start Alignment Method is specified as Projection.
Either Location Line, Top of Element, Center of Element, Bottom of Element,
Specifies the vertical location of the analytical model at the start of the beam.
End Alignment Method - Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam end position are automatically justified or have a defined projection.
Either Auto-detect or Projection. Specifies if the horizontal and vertical references of the beam end position are automatically justified or have a defined projection.
End y Projection - Either Location Line, Left of Element, Center of Element, Right of Element, , or . Available when End Alignment Method is specified as Projection.
Either Location Line, Left of Element, Center of Element, Right of Element,
Specifies the horizontal location of the analytical model at the end of the beam.
End z Projection - Either Location Line, Top of Element, Center of Element, Bottom of Element, , , or . Available when End Alignment Method is specified as Projection.
Either Location Line, Top of Element, Center of Element, Bottom of Element,
Specifies the vertical location of the analytical model at the end of the beam.
End release - Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Start Fx - The translational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
Start Fy - The translational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
Start Fz - The translational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
Start Mx - The rotational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
Start My - The rotational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
Start Mz - The rotational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the start end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
End Release - Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
Specifies the end release condition: either Fixed, Pinned, Bending Moment or User Defined. User Defined allows you to enable/disable each of the end release conditions.
End Fx - The translational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the force is not available.
End Fy - The translational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the force is not available.
End Fz - The translational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
The translational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the force is not available.
End Mx - The rotational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local x-axis. When selected the degree of freedom is released and the moment is not available.
End My - The rotational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local y-axis. When selected the degree of freedom is released and the moment is not available.
End Mz - The rotational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
The rotational release at the end of the brace along the local z-axis. When selected the degree of freedom is released and the moment is not available.
Member Forces - Specifies the internal forces at the start and end of the analytical beams and braces. This data communicates load information for both documentation and connection fabrication. Click Edit to enter user-defined force and moment values.
Specifies the internal forces at the start and end of the analytical beams and braces. This data communicates load information for both documentation and connection fabrication. Click Edit to enter user-defined force and moment values.
Identity Data - Member Number
Member Number - An identifier created for the analytical member. This value should be unique across Analytical Beams, Analytical Braces and Analytical Columns in a project. Revit warns you if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Review Warning Messages.
An identifier created for the analytical member. This value should be unique across Analytical Beams, Analytical Braces and Analytical Columns in a project. Revit warns you if the number is already used but allows you to continue using it. You can see the warning using the Review Warnings tool. See Review Warning Messages.
Comments - User comments.
User comments. - Phasing
Phasing - Phase Created
Phase Created - Indicates in which phase the beam was created. See Project Phasing.
Indicates in which phase the beam was created. See Project Phasing.
Approved document F, Ventilation, defines airtightness as a general descriptive term for the resistance of the building envelope to infiltration with ventilators closed. The greater the airtightness at a given pressure difference across the envelope, the lower the infiltration.
It suggests that air permeability is the physical property used to measure the airtightness of the building fabric. It is defined as air leakage rate per hour per square metre of envelope area at a test reference pressure differential across the building envelope of 50 Pascal (50 N/m2). The design air permeability is the target value set at the design stage.
The Air Tightness Testing and Measurement Association (ATTMA) defines air leakage as the '...uncontrolled flow of air through gaps and cracks in the fabric of a building. It is sometimes known as infiltration or draughts. Air leakage is not to be confused with ventilation, which is controlled airflow in and out of a building'.
Approved Document E suggests that infiltration '...is the uncontrolled exchange of air between inside a building and outside through cracks, porosity and other unintentional openings in a building, caused by pressure difference effects of the wind and/or stack effect.'
Wherever infiltration occurs, there is a corresponding exfiltration somewhere else in the building. During the summer, infiltration can bring humid, outdoor air into buildings. In winter, exfiltration can result in moist indoor air moving into cold wall cavities and can result in condensation and ultimately mould or rot.
While air infiltration is not desirable, it is important for buildings to have sufficient purpose-provided ventilation. According to the Building Services Research and Information Association (BSRIA), 'Project teams should design and construct the building fabric to be reasonably airtight, and also provide natural or mechanical ventilation systems that maintain good indoor air quality while minimising energy use. In other words: build tight, ventilate right.' Ref BSRIA Topic Guide - Airtightness.
The term 'building fabric' refers to structural materials, cladding, insulation, finishes, etc., that enclose the interior of a building, separating the internal from the external.
Very broadly, for most buildings, the building fabric will include a number of elements:
The roof. - External walls.
External walls. - Windows.
Windows. - Doors.
Doors. - The lowest floor.
The lowest floor. - Each of these will in turn be assemblies of a number of components.
Each of these will in turn be assemblies of a number of components.
The building fabric serves to: -
Protect the building occupants from the weather, such as wind, rain, solar radiation, snow, and so on.
Regulate the indoor environment in terms of temperature, humidity, moisture, and so on.
Provide privacy for occupants. - Prevent the transmission of noise.
Prevent the transmission of noise. - Provide security for occupants and the building contents.
Provide security for occupants and the building contents.
Provide safety, for example preventing the spread of fire or smoke.
Provide views into and out of the building.
Provide access between the inside and the outside of the building.
It is also generally a major part of the structure of the building.
As a result, building fabric is now seen much less as just a stylistic add on to a building, but more as a fundamental part of to the way the building operates. Increasingly, this is resulting in the creation of complex, multi layered elements to the building fabric, and the use of modern materials such as high performance glazing, architectural fabrics, active shading, and so on.
The building fabric will usually contain openings as a means of providing physical access, admitting daylight, providing natural or mechanical ventilation, supplying services, allowing drainage, and so on. In some cases, this may conflict with other performance requirements, for example, openings may cause security, privacy or noise nuisance issues. These potential conflicts require careful consideration and design, which may include the use of screens, shades, baffles, and so on.
Junctions between the elements that make up the building fabric can also cause problems, for example creating a cold bridge between the inside and the outside.
In terms of the built environment, the term safety generally refers to the condition of being protected, or safe, from hazards and other undesirable events. As construction is one of the most dangerous industries to work in, the positive control and management of hazards and risks to achieve a sufficiently-high level of safety is very important, and is often a legal requirement.
From a safety perspective, a hazard is a condition with the potential to cause physical impairment or health consequences in people or other types of life.
Safety audits are carried out to assess health and safety processes on construction sites, considering; legislative requirements, industry best practice, and the contractors own health and safety management systems.
Construction companies use a wide range of safety practices as part of their safety management programmes, with an increasing emphasis on creating a safety culture throughout the organisation.
The term safety can also be used to refer to how safe or protected against harmful events a building or structure is when it is in use. This can be in relation to extreme weather, earthquakes, security, operational failures or hazards, and so on
A hazard is a situation that creates a threat to life, health, property, the environment, personal integrity, and so on. Hazards differ from risks, in that risks describe the potential for a situation such as a hazard to cause harm.
From a health and safety perspective, a hazard may be seen as a condition with the potential to cause physical impairment or health consequences in people (or any other type of life). In a project environment, a hazard is anything that may affect the success of project activities or the project as a whole. Similarly, companies, ventures, physical assets, the environment and society face hazards.
Most hazards are potential or latent but a hazardous situation becomes 'effective', it can cause an incident, an accident or a even a disaster.
The Lifting Operations and Lifting Equipment Regulations (LOLER) place legal duties and responsibilities on those who own, operate or have control over lifting equipment. It was created under the Health and Safety at Work etc. Act 1974, and came into force in 1998, replacing several preceding pieces of legislation which had previously regulated the use of lifting equipment.
LOLER defines lifting equipment as work equipment for lifting or lowering loads and includes its attachments used for anchoring, fixing or supporting it.
Insurer - Insurer (sometimes called the insurance provider, insurance company or underwriter) refers to a company that provides various types of insurance policy to indemnify individuals, groups, organisations, government agencies and other bodies. Such insurance policies can provide cover and may pay out in cases of ill health, job loss, accidents, theft, property damage, professional liability and other instances where individuals and companies may face heavy losses if uninsured.
Insurer (sometimes called the insurance provider, insurance company or underwriter) refers to a company that provides various types of insurance policy to indemnify individuals, groups, organisations, government agencies and other bodies. Such insurance policies can provide cover and may pay out in cases of ill health, job loss, accidents, theft, property damage, professional liability and other instances where individuals and companies may face heavy losses if uninsured.
The insurance policy is a sort of contract stipulating the conditions under which the insurer promises to compensate the insured (those who have purchased a policy) against a stated loss or losses.
For more information see: Insurance. -
The insurer is not the same as the insurance broker or agent. The latter advises those seeking to buy insurance, arranges cover and passes on the premium (plus commission for their effort) to the insurer.
Recent times have seen many small, high street brokers put out of business, as insurance can now often be arranged directly with insurers over the internet.
In very general terms, an agreement is an understanding and statement of intent between two or more parties, which has often been negotiated and sets out their respective rights and responsibilities.
Whether an agreement is legally enforceable will depend on its type and form. A non-binding agreement, also known as a gentlemans agreement is typically oral (but can be written), or may be part of an unspoken agreement, and relies on an understanding between the parties that they will honour the agreement as opposed to it being enforceable. A binding agreement is also known as a contract and creates rights and obligations between the parties.
There are four essentials in forming a contract:
Two or more parties. - An intention to create legal relations.
An intention to create legal relations. - An agreement.
An agreement. - Consideration. (Save for contracts made under seal, and subject to the Contracts (Rights of Third Parties) Act, the courts will not enforce gratuitous promises. There must be valuable consideration. Valuable consideration is 'something of value in the eye of the law'.
Consideration. (Save for contracts made under seal, and subject to the Contracts (Rights of Third Parties) Act, the courts will not enforce gratuitous promises. There must be valuable consideration. Valuable consideration is 'something of value in the eye of the law'.
For more information see: Essentials of a contract.
Contracts may be executed under seal (signed by the parties, witnessed and most importantly made clear that it is executed as a deed) or under hand (a 'simple contract' that is just signed by the parties). For more information see: Contracts under seal v under hand.
Contract documents for a construction contract will often include articles of agreement. These set out the core obligations of the parties involved. Typically, they consist of four sections:
Recitals. - Articles.
Articles. - Contract Particulars.
Contract Particulars. - Attestation.
Attestation. - For more information, see Articles of agreement.
For more information, see Articles of agreement.
When an agreement is made to appoint consultants, this generally referred to as an appointment rather than a contract. For more information see: Appointing consultants.
Other types of contractual agreement include: -
Framework agreements, often used by clients that are continuously commissioning construction work, to allow them to invite tenders from suppliers of goods and services to be carried out over a period of time on a call-off basis as and when required. For more information, see Framework contract.
Partnering is a broad term used to describe a collaborative management approach that encourages openness and trust between parties to a contract. The parties become dependent on one another for success and this requires a change in culture, attitude and procedures throughout the supply chain. Partnering can be arranged either by use of a traditional contract with a separate partnering agreement, or by use of a contract with an aligned partnering agreement. For more information, see Partnering.
Pre-Construction Services Agreements (PCSAs) enable clients to employ contractors before the main construction contract commences. Typically, they are part of a two-stage tender process, used in the first stage to procure contractor involvement in the design process. For more information, see Pre-construction services agreement.
Pre-construction services agreement PCSA - Pre-Construction Services Agreements (PCSAs), sometimes referred to as Pre-Contract Services Agreements, enable clients to employ contractors before the main construction contract commences.
Pre-Construction Services Agreements (PCSAs), sometimes referred to as Pre-Contract Services Agreements, enable clients to employ contractors before the main construction contract commences.
Typically they are part of a two-stage tender process, used in the first stage to procure contractor involvement in the design process. This can enable the contractor to:
Contribute to the design process itself. - Advise on buildability, sequencing, and construction risk.
Advise on buildability, sequencing, and construction risk.
Advise on the packaging of the works (and the risks of interfaces between packages).
Advise on the selection of specialist contractors. - Help develop the cost plan and construction programme.
Help develop the cost plan and construction programme.
Help develop the method of construction. - Obtain prices for work packages from sub-contractors or suppliers on a open book basis.
Obtain prices for work packages from sub-contractors or suppliers on a open book basis.
Prepare a site layout plan for the construction stage showing temporary facilities.
Draft the preliminaries for specialist and trade contractor bid documents.
Assist with any planning application on matters concerning the build phase, such as; waste disposal proposals, construction traffic movements, tree preservation protection, etc.
This early involvement of the contractor should improve the buildability and cost-certainty of the design as well as creating a better integrated project team and reducing the likelihood of disputes.
The PCSA will define the services that are required of the contractor during the pre-construction phase and is generally similar to a consultancy agreement. It should make clear whether the contractor is undertaking design work, whether they will have any design liability, and what will happen to this liability if they are not appointed for the second stage. It should also set out the method of payment, and any provisions for deferred payment.
The contractor appointed under the PCSA will not necessarily be appointed for the second-stage construction contract. However, the client inevitably loses leverage in the second-stage of the tender process, as the contractor becomes embedded in the team and potential competitors lose interest once they find out that another contractor has been awarded the first-stage tender.
However, a longer period of familiarity with the project creates better relationships as well as a reduction in learning curves and programme performance, and so, whilst tender prices for two-stage contracts may initially be higher than single-stage tenders, which are subject to full competition, the final account tends to include fewer variations and fewer claims. Competition can be introduced into the second stage by an open-book approach to the tendering of sub-contracts.
It is important that the client ensures they have some means of securing an alternative bid if second-stage negotiations fail, albeit this is likely to result in delays and difficulties regarding design liability.
PCSAs are often used on design and build projects to obtain early input from the contractor. They can also be used to obtain pre-construction services by specialists, appointed either by the contractor, or by the client (for example on a construction management contract) or on Private Finance Initiative (PFI) or Public Private Partnership (PPP) projects to obtain contractor input to a consortium bidding for a project.
The supply chain is the interconnected hierarchy of supply contracts necessary to procure a built asset. Managing the supply chain involves understanding the breakdown and traceability of products and services, organisations, logistics, people, activities, information and resources that transform raw materials into a finished product that is fit for its purpose.
Unlike the automotive industry, the construction industry has the particular difficulty that every building is different, a unique prototype, developed by a team of consultants, contractors and other suppliers that may never have worked together before and may never work together again.
To add to the complexity, different procurement systems place elements of supply chain management with varying disciplines and organisations.
On a 'traditional' building project, design consultants are first tier suppliers, working for the client, and the contractor has a supply chain of sub-contractors and specialist suppliers. On PFI or design and build projects, however, there may be just one first tier supplier (sometimes the contractor) and design consultants will work for them as part of their supply chain.
On large or complex projects, responsibility and performance may cascade down the supply chain to a plethora of suppliers sometimes unknown to management at the top of the chain. For more information see: Suppliers.
One of the problems in the construction industry is that the first and second tier of the supply chain typically sign up to fairly onerous agreements, but as the chain develops, so the contractual liabilities decrease until suppliers at the end of the chain are often not locked in at all.
The key to supply chain management is providing a strategy that aligns with the project programme. This starts at the design stage, scoping the work into packages. Early evaluation based on feedback from the supply chain can produce enormous cost benefits and value. Capacity and production capability in a market controlled by supply and demand are particularly significant if programme bottlenecks are to be avoided.
Built asset - PAS 1192-5:2015 Specification for security-minded building information modelling, digital built environments and smart asset management, defines a built asset as a:
PAS 1192-5:2015 Specification for security-minded building information modelling, digital built environments and smart asset management, defines a built asset as a:
'building, multiple buildings (e.g. a site or campus) or built infrastructure (e.g. roads, railways, pipelines, dams, docks, etc.) that is the subject of a construction project or where the asset information is held in a digital format'
It suggests that a built asset may include associated land or water, such as the catchment area for a water company or the navigation channels for a dock and that it may comprise a portfolio or network of assets.
Building information modelling BIM - BIM guide 600.jpg
BIM guide 600.jpg -
Contents - [hide]
[hide] - 1 Definition
1 Definition - 2 Maturity levels
2 Maturity levels - 3 Policy
3 Policy - 4 Uptake
4 Uptake - 5 Characteristics of BIM
5 Characteristics of BIM - 6 Software
6 Software - 7 Protocols standards and tools
7 Protocols standards and tools - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - Definition
Definition - Building Information Modelling (BIM) is a very broad term that describes the process of creating and managing digital information about a built asset such as a building, bridge, highway or tunnel.
Building Information Modelling (BIM) is a very broad term that describes the process of creating and managing digital information about a built asset such as a building, bridge, highway or tunnel.
ISO 19650:2019 defines BIM as: -
Use of a shared digital representation of a built asset to facilitate design, construction and operation processes to form a reliable basis for decisions.
Maturity levels - The range of BIM maturity levels have been categorised as:
The range of BIM maturity levels have been categorised as:
Level 0: Unmanaged CAD (Computer Aided Design).
Level 1: Managed CAD in 2D or 3D.
Level 2: Managed 3D environment with data attached, but created in separate discipline models.
Level 3: Single, online, project model with construction sequencing, cost and life-cycle management information.
These maturity levels are not defined in ISO 19650:2019 or related guidance.
Policy - In the UK, the Government Construction Strategy published in May 2011, stated that the '...government will require fully collaborative 3D BIM (with all project and asset information, documentation and data being electronic) as a minimum by 2016'.
In the UK, the Government Construction Strategy published in May 2011, stated that the '...government will require fully collaborative 3D BIM (with all project and asset information, documentation and data being electronic) as a minimum by 2016'.
This represents a minimum requirement for Level 2 BIM on centrally-procured public projects from April 2016.
Uptake - NBS has suggested that adopting BIM can cost a practice 10,000 per workstation (ref. NBS: National BIM report 2012). However, this depends on whether implementation is simply an exercise in buying hardware and software and then training staff to use it, or whether it is part of a wider process of business change.
NBS has suggested that adopting BIM can cost a practice 10,000 per workstation (ref. NBS: National BIM report 2012). However, this depends on whether implementation is simply an exercise in buying hardware and software and then training staff to use it, or whether it is part of a wider process of business change.
The justification for this cost is in the value that adopting BIM brings to a project throughout its life-cycle. The BIM Task Group suggest that '...if successfully implemented, (BIM) will help organisations strip the waste from their processes which in many cases could be in the bandwidth of 20-30%' (ref. BIM Task Group FAQ's).
The requirement for the adoption of BIM in the public sector has lead to an increase in uptake, meaning that the UK now ranks alongside Singapore, USA and Scandinavia (in particular Finland) in terms of BIM usage. Adoption of BIM in the UK is most common among architects and larger contractors, while there is less take-up by services engineers, facilities managers and smaller contractors.
The 2012 NBS BIM survey found that 31% of respondents were using BIM. By the 2020 survey, this had increased to 73%.
However, the 2017 Construction Manager BIM survey revealed 49% of clients did not make BIM a requirement on projects, and only 20% said they asked for BIM Level 2 on all projects, and a survey of 173 manufacturers published by NBS in conjunction with the Construction Products Association (CPA) in November 2017, found that more than half felt the BIM mandate had not been successful because of a lack of rigorous enforcement. (ref. https://www.thenbs.com/knowledge/nbs-manufacturers-bim-report-2017).
In May 2018, the NBS 2018 National BIM Report found that 62% did not think the government was enforcing the BIM mandate. Ref https://www.thenbs.com/knowledge/the-national-bim-report-2018
The 2019, the NBS National BIM Report found that 69% of respondents were aware of and using BIM. However, the report suggested there was an emerging two-speed industry, and that there was a fall in awareness of government activity. https://www.thenbs.com/knowledge/national-bim-report-2019
Characteristics of BIM - Fundamentally, the purpose of BIM is to ensure that appropriate information is created in a suitable format at the right time so that better decisions can be made throughout the design, construction and operation of built assets. It is not about creating a 3D model for its own sake, and it is not an add-on process. BIM is fundamental to the way a project is set up and run.
Fundamentally, the purpose of BIM is to ensure that appropriate information is created in a suitable format at the right time so that better decisions can be made throughout the design, construction and operation of built assets. It is not about creating a 3D model for its own sake, and it is not an add-on process. BIM is fundamental to the way a project is set up and run.
BIM centres around the creation of employer's information requirements (EIR), which define the information that the employer wishes to procure in order to develop and operate a built asset. Setting this out in a contract document ensures that appropriate information is created in a suitable format at the right time.
Very broadly, building information that might be required is categorised as:
2D. - 3D.
3D. - 4D (including time / programme information).
4D (including time / programme information).
5D (including cost information). - 6D (including facilities management information).
6D (including facilities management information). - For more information see: BIM dimensions.
For more information see: BIM dimensions. -
At level 2, building information models are likely to comprise a series of federated models prepared by different design teams, including model files, documents and structured data files containing non-geometric information about the facility, floors, spaces, systems and components. Together these create a digital replica of the built asset that starts by representing design intent, but by handover, reflects what has actually been built and installed.
The creation of a geometric model as part of this process allows buildings to be conceived collaboratively and tested virtually, before they are built and operated for real. This should reduce the problems that are encountered in construction and occupation. See clash avoidance for more information.
These models are created from a series of parametric objects. Each object is defined only once and then placed in the model in multiple locations as required. If the object is then changed, these changes will appear throughout the model. This makes models automatically consistent and reduces errors. See parametric modelling for more information.
The common data environment (CDE), is the single source of information for the project, used to collect, manage and disseminate documentation, the graphical model and non-graphical data for the whole project team. Creating this single source of information facilitates collaboration between project team members and helps avoid duplication and mistakes.
The Building Regulations set out requirements for specific aspects of building design and construction. Regulation 26 of the building regulations states that Where a building is erected, it shall not exceed the target CO2 emission rate for the building,
The target CO2 emission rate (TER) sets a minimum allowable standard for the energy performance of a building and is defined by the annual CO2 emissions of a notional building of the same size and shape to the proposed building. TER is expressed in annual kg of CO2 per m2.
The Dwelling emission rate (DER) is the actual CO2 emission rate of self-contained dwellings and individual flats (excluding common areas) based on their actual specification.
The DER for the proposed building must not exceed the TER.
Before construction begins, a design stage calculation must be issued to the Building Control Body (BCB), setting out the TER, and DER for the proposed building, along with details of its proposed specification.
Within 5 days of the completion of the construction, a report must be issued to the Building Control Body (BCB), setting out the TER, and DER of the completed building, along with any changes that have been made to the specification, and an energy performance certificate (EPC). These as-built calculations require that an air-permeability test is carried out to ensure that the building envelope has been constructed to a suitably high level of workmanship so that air (and with it, heat) will not leak through the building fabric. In addition, the BCB is likely to require a commissioning notice.
The TER and DER can be calculated by following the Standard Assessment Procedure (SAP). This can be done by using a computer program approved for SAP calculations by BRE on behalf of the government.
NB 2013 changes to part L of the building regulations which came into force on 6 April 2014 introduced a Target Fabric Energy Efficiency (TFEE) rate for dwellings to sit alongside the Target Emission Rate. The TFEE is the minimum energy performance requirement for a new dwelling. The Dwelling Fabric Energy Efficiency (DFEE) rate is the actual energy performance of the new dwelling. The DFEE must not exceed the TFEE. See Target fabric energy efficiency rate for more information.
The word insulate means to protect something by interposing a material between it and other elements that prevents transmission between them. The word insulation refers to the material that is interposed.
Insulation may be used in the construction industry for a number of different purposes:
Thermal insulation to prevent the transmission of heat, typically between the inside and outside of a building. For more information see: Thermal insulation.
Acoustic insulation to prevent the transmission of sound, for example between a recording studio and a performance space. For more information see: Acoustic insulation.
Fire insulation to prevent the passage of fire between spaces or components.
Electrical insulation to contain and separate electrical conductors.
There are a number of articles on Designing Buildings Wiki about insulation:
Principles of enclosure - Enclosure is the term given to any part of a building that physically separates the external from the interior environment. It is often referred to as the building envelope, although enclosure is considered the more precise term.
Enclosure is the term given to any part of a building that physically separates the external from the interior environment. It is often referred to as the building envelope, although enclosure is considered the more precise term.
Human physiology is capable of tolerating only a narrow range of environmental conditions. Beyond this range, health and wellbeing are compromised. Through the materialisation of volumes, architecture is able to create enclosed spaces in the form of structures. A building consists of a collection of spaces bounded by separators of the interior environment, and separators of the exterior environment (the enclosure).
Where exactly the enclosure begins and the exterior environment stops can sometimes be unclear, such as in the case of buffer spaces such as garages, screened porches, attics or vented crawlspaces.
A porch is a covered, single-storey structure that can be enclosed, and projects out from a house or other building. It is a particularly popular option for extending a domestic building, typically at the front entrance, where it can provide additional space, allow the creation of a draft lobby and create an architectural focus. It can also be relatively inexpensive to construct.
A porch can help reduce heat loss from the building, improve energy efficiency and create useful storage space for coats and shoes.
Generally, a porch consists simply of low-level brick dwarf walls, columns, windows and a door. It will require foundations, and the junctions between the walls of the porch and those of the existing building will need to be properly sealed.
Internally, they can be left as open brick or plastered and painted. They will often have a light fitting and an electric socket and a door bell, intruder alarm or other entry system.
Due to their relatively small size, a porch may not require planning permission (although they may in a conservation area or for a listed building, so it is best to check with the local planning authority). Building regulations approval may also be required if the porch is not separated from the house by an internal door and is heated, or if there are structural, accessibility or drainage implications (again, it is best to check with the building control department of the local authority).
There are several different types of porch and it depends to a considerable extent on the existing front entrance as to which is the most suitable. For example, a plain front (as is common with terraced houses) will typically only be suitable for a mounted canopy above the door; a recessed front door (as is common with Victorian and Edwardian houses) will require the recess being blocked in with brickwork and/or glass. Buildings with existing entrance canopies may be capable of being infilled with timber, brick and/or glass, although care should be taken to install a damp-proof course (DPC).
When choosing or designing a porch it is important to make sure that it suits the existing building. Typically this will involve using the same materials, although in some cases, contrast with the existing building can be appropriate. Often, the existing front door can be moved to the exterior face of the porch (if it is suitable), with a new interior door installed between the building and the porch to create a draft lobby.
Porches will often incorporate a large amount of glazing in order to maximise natural light, and so the window design should complement those of the rest of the building or, at least, the frontage.
A lobby is a space from which one or more other rooms or corridors can be accessed, typically found near the main entrance to a building. It may be used for access, circulation, or as a waiting area, and is derived from the latin lobium, meaning a covered walk, or portico. A lobby may be referred to as a vestibule, anteroom or foyer.
The word lobby can also be used specifically to refer to a large space adjacent to a legislative chamber where 'lobbying' may take place (that is, attempting to influence members of the legislature).
Approved Document M suggests that an entrance lobby may be used to:
Limit air infiltration. - Maintain comfort by controlling drafts.
Maintain comfort by controlling drafts. - Increase security.
Increase security. - Provide transitional lighting.
Provide transitional lighting. - It should be designed to allow a wheelchair user (and companion), or a person pushing a pram to move clear of one set of doors before opening the other set. The minimum size therefore is related to the size of the door swing into the lobby.
It should be designed to allow a wheelchair user (and companion), or a person pushing a pram to move clear of one set of doors before opening the other set. The minimum size therefore is related to the size of the door swing into the lobby.
It should be free from obstructions or distracting reflections, and should be provided with a cleaning mat if rainwater may be transported into the lobby.
Approved Document B refers to a protected lobby, which is a lobby which is adequately protected from fire in adjoining accommodation by fire-resisting construction and a firefighting lobby, which is a protected lobby providing access from a firefighting stair to the accommodation area and to the associated firefighting lift.
Approved Document B refers to as a firefighting lobby as, '...a protected lobby providing access from a firefighting stair to the accommodation area and to any associated firefighting lift.
A corridor is a form of hallway or gallery which is typically narrow in comparison to its lenght and acts as a passage connecting different parts of a building. A corridor often has entry points to rooms along it.
Despite being a normal feature of many modern buildings, corridors did not become common until the late-17th century, and were only first used widely in the 19th century. Prior to the use of corridors as a means of circulation, people would simply flow from one room into the next.
It has been theorised that the proliferation of corridors was driven to a certain extent by socio-economic factors and evolving moral attitudes. Corridors were a means of separating the occupants of a building, such as servants from those they served, inmates from the prison guards, workers from supervisors, and so on. They created privacy, in that it was no longer necessary to go through rooms, it was only necessary to go in to them.
Corridors also helped increase the efficiency with which people could move through buildings, while also turning rooms into a series of dead ends by separating circulation from destination.
The design of corridors is largely determined by the functions of the building. Hospital corridors will need to be wide enough to allow bi-directional flow of traffic, including beds and wheelchairs. Hotel corridors need to be robust enough for suitcase wheels, trolleys, and so on. Corridors may need access to natural light from windows, or be lit well artificially so as to avoid dark corners and allow easy circulation.
However, they can sometimes be soulless 'between' spaces, with no particular character or function, anonymous decoration, poor-quality artificial light and the feel of a prison offering nothing but a series of locked cell doors.
The worlds longest corridor is in RAF Mount Pleasant on the Falkland Islands. Nicknamed the Death Star Corridor, it is half a mile (800 m) long, and links the barracks, messes, and recreational/welfare areas of the station.
There are a number of statutory requirements for the design of corridors. Part M of the building regulations sets standards for circulation spaces so as to make them accessible, this includes required widths to allow circulation by people in wheelchairs. Part B of the building regulations sets standards for fire safety; corridors may form part of escape routes, with required minimum widths, and may be protected corridors, that is, corridors which are protected from fire in adjoining accommodation by fire-resisting construction.
Approved document B, Fire Safety, Volume 1 Dwelling houses, defines a room as: 'An enclosed space within a building that is not used solely as a circulation space. The term includes not only conventional rooms, but also cupboards that are not fittings and large spaces such as warehouses and auditoria. The term does not include cavities such as ducts, ceiling cavities and roof spaces.'
The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, suggests that room means: any enclosed part of a storey intended for human occupation or, where no part of any such storey is so enclosed, the whole of that storey, but excepting in either case any part used solely as a bathroom, shower room, washroom, toilet, stair or circulation area.
In a building, headroom is the clear, vertical height (vertical clearance) which exists from the top surface of a floor to the underside of a:
Ceiling. - Door head,
Door head, - Staircase ceiling.
Staircase ceiling. - Between two floors, the headroom is the clear vertical space between the two decks, from the top of the finished floor level of the lower deck, to the underside of the soffit of the upper deck. Low headroom may increase the likelihood of injury or the difficulty of manoeuvring large objects.
Between two floors, the headroom is the clear vertical space between the two decks, from the top of the finished floor level of the lower deck, to the underside of the soffit of the upper deck. Low headroom may increase the likelihood of injury or the difficulty of manoeuvring large objects.
The headroom may or may not be sufficient to allow people to pass under easily. If not sufficient, it will not be possible to pass through without crouching or striking the top surface.
Stairs - On a flight of stairs, the headroom is the vertical distance between the pitch line (or nosing line) and the ceiling, taking into account any bulkheads. Approved Document K of the Building Regulations (section 1.11, diagram 1.3) stipulates a minimum headroom of 2m for all building types whether on the stairs or on a landing.
On a flight of stairs, the headroom is the vertical distance between the pitch line (or nosing line) and the ceiling, taking into account any bulkheads. Approved Document K of the Building Regulations (section 1.11, diagram 1.3) stipulates a minimum headroom of 2m for all building types whether on the stairs or on a landing.
Tunnels and bridges - Headroom may also refer to the clear, vertical height from a roads top surface to the underside of a bridge or to the crown of a tunnel (or the ceiling of some buildings such as car parks). A sign indicating low headroom warns that some vehicles may not be able to pass through without hitting the underside of the structure. In these cases, the clear height of the available headroom will be displayed, and there may be additional warning signs in advance of the low headroom or barriers to try to prevent impact.
Headroom may also refer to the clear, vertical height from a roads top surface to the underside of a bridge or to the crown of a tunnel (or the ceiling of some buildings such as car parks). A sign indicating low headroom warns that some vehicles may not be able to pass through without hitting the underside of the structure. In these cases, the clear height of the available headroom will be displayed, and there may be additional warning signs in advance of the low headroom or barriers to try to prevent impact.
Culverts and outflows - Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines headroom as the: Vertical gap between the water surface and the roof (soffit) of a culvert or outfall to allow for floating debris (also known as air draught).
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines headroom as the: Vertical gap between the water surface and the roof (soffit) of a culvert or outfall to allow for floating debris (also known as air draught).
Introduction - Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a ceiling as:
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a ceiling as:
'Part of a building that encloses a room, protected shaft or circulation space and is exposed overhead. NOTE: The soffit of a rooflight, but not the frame, is included as part of the surface of the ceiling. An upstand below a rooflight is considered as a wall.'
Ceilings help create enclosure of and separation between spaces, they help to control the diffusion of light and sound around a room, and help prevent the passage of sound between rooms. They have fire resistant properties and may also accommodate building services such as vents, lighting, sprinkler heads and so on, as well as being able to conceal other services such as ducts, pipes and wiring.
Types of ceiling - Exposed ceilings
Exposed ceilings - In some buildings, it is possible to omit a 'finished' ceiling completely and simply expose the structural and mechanical components of the building to the interior. This offers the advantages of economy and ease of access for maintenance, and can also expose the thermal mass of the building. The thermal mass of exposed ceilings can be further exploited by the installation of heating or cooling elements such as chilled beams.
In some buildings, it is possible to omit a 'finished' ceiling completely and simply expose the structural and mechanical components of the building to the interior. This offers the advantages of economy and ease of access for maintenance, and can also expose the thermal mass of the building. The thermal mass of exposed ceilings can be further exploited by the installation of heating or cooling elements such as chilled beams.
If well designed and installed, roof structures and floor structures can be aesthetically pleasing if left exposed ot the space below, such as timber beams, concrete slabs, space trusses and so on. The mechanical elements at ceiling level can also create an attractive aesthetic effect.
A permeable suspended ceiling such as an open lattice is sometimes suspended below exposed ceilings. This can be an inexpensive and visually dramatic way of partially concealing services without preventing the movement of air. This technique is often used in retail spaces.
Tightly-attached ceilings - Ceilings made of gypsum, plasterboard, tongued and grooved timber and so on, may be attached tightly to timber joists or rafters, steel joists or concrete slabs. Careful detailing is required where beams or other obstructions protrude through the plane of the ceiling, such as vents, conduits, pipes, sprinkler heads and so on.
Ceilings made of gypsum, plasterboard, tongued and grooved timber and so on, may be attached tightly to timber joists or rafters, steel joists or concrete slabs. Careful detailing is required where beams or other obstructions protrude through the plane of the ceiling, such as vents, conduits, pipes, sprinkler heads and so on.
Suspended ceilings - Suspended ceilings (sometimes referred to as dropped ceilings or false ceilings) are secondary ceilings suspended from the structure above (typically a floor or roof slab), creating a void between the underside of the slab and the top of the suspended ceiling.
Suspended ceilings (sometimes referred to as dropped ceilings or false ceilings) are secondary ceilings suspended from the structure above (typically a floor or roof slab), creating a void between the underside of the slab and the top of the suspended ceiling.
As well as concealing the underside of the slab, this void can provide a useful space for the distribution of heating, ventilation and air conditioning (HVAC) services and plumbing and wiring services, as well as providing a platform for the installation of speakers, light fittings, wireless antenna, CCTV, fire and smoke detectors, motion detectors, sprinklers and so on. It can also provide an air plenum, in which the void itself forms a pressurised duct to supply air to, or extract it from the occupied space below.
For more information see Suspending ceilings. -
Interstitial space - Interstitial spaces, such as interstitial ceilings allow for a larger space to be located between regular-use floors. They generally include an access walkway, and have a low height. They are commonly used in buildings such as hospitals and laboratories that have complex services which may include:
Interstitial spaces, such as interstitial ceilings allow for a larger space to be located between regular-use floors. They generally include an access walkway, and have a low height. They are commonly used in buildings such as hospitals and laboratories that have complex services which may include:
Air-conditioning ducts. - Water and waste pipework.
Water and waste pipework. - Electrical and communications wiring.
Electrical and communications wiring. - Fuel gas lines.
Fuel gas lines. - Compressed air lines.
Compressed air lines. - Oxygen.
Oxygen. - Chilled water.
Chilled water. - Vacuum pipework.
Vacuum pipework. - Chemical waste pipework.
Chemical waste pipework. - As ducts and pipework can occupy a significant amount of space, often require continual maintenance and are subject to frequent change, interstitial ceilings can allow for maintenance and updating work to be carried out without interruption of activities in the spaces above and below.
As ducts and pipework can occupy a significant amount of space, often require continual maintenance and are subject to frequent change, interstitial ceilings can allow for maintenance and updating work to be carried out without interruption of activities in the spaces above and below.
Introduction - Maintenance is the process of ensuring that buildings and other assets retain a good appearance and operate at optimum efficiency. Inadequate maintenance can result in decay, degradation and reduced performance and can affect heath and threaten the safety of users, occupants and others in the vicinity.
Maintenance is the process of ensuring that buildings and other assets retain a good appearance and operate at optimum efficiency. Inadequate maintenance can result in decay, degradation and reduced performance and can affect heath and threaten the safety of users, occupants and others in the vicinity.
Depending on its design, quality of materials and workmanship, function and location, buildings deteriorate at different rates and require different levels of attention. No building will ever be maintenance-free, but the quality of the design and workmanship can minimise the level required.
Maintenance can help: -
Prevent the process of decay and degradation. - Maintain structural stability and safety.
Maintain structural stability and safety. - Prevent unnecessary damage from the weather or from general usage.
Prevent unnecessary damage from the weather or from general usage.
Optimise performance. - Help inform plans for renovation, refurbishment, retrofitting or new buildings.
Help inform plans for renovation, refurbishment, retrofitting or new buildings.
Determine the causes of defects and so help prevent re-occurrence or repetition.
Ensure continued compliance with statutory requirements. - For maintenance to be most effective, it should be organised through a programme of cyclical maintenance. At the most basic level this includes daily routines, and works upwards to periodic programmes of weekly, monthly, semi-annual, annual, quinquennial and so on routines.
For maintenance to be most effective, it should be organised through a programme of cyclical maintenance. At the most basic level this includes daily routines, and works upwards to periodic programmes of weekly, monthly, semi-annual, annual, quinquennial and so on routines.
At the quinquennial point and beyond, architects, engineers and surveyors may become involved to inspect for structural and other serious defects (in particular for historic buildings), and the long-term maintenance plan may be revised and updated.
Types of maintenance - Maintenance can be classified as:
Maintenance can be classified as: -
Planned maintenance: Carried out on a regular basis, such as servicing boilers.
Preventive maintenance: Carried out in order to keep something in working order or extend its life, such as replacing cracked roofing tiles before inclement weather.
Corrective maintenance: This involves repairing something that has broken, such as a window or guttering.
Front-line maintenance: This involves maintaining something while it is still in use, such as repainting and decorating an occupied building.
Proactive maintenance: Maintenance work that is undertaken to avoid failures or to identify defects that could lead to failure.
Reliability centred maintenance: A combination of maintenance strategies used to ensure a physical asset continues to function correctly.
Scheduled maintenance: Preventive maintenance carried out in accordance with predetermined intervals, number of operations, hours run, and so on.
Planned and preventative maintenance (PPM) are sometimes grouped together to distinguish them from unplanned maintenance undertaken in response to an incident. PPM may be scheduled on a PPM calendar.
For more information, see Planned preventive maintenance.
Maintenance can also be classified as exterior or interior works.
Common maintenance tasks include: -
Exterior painting and plastering. - Landscaping and gardening.
Landscaping and gardening. - Paving repairs.
Paving repairs. - Window and door repairs.
Window and door repairs. - Debris/rubbish removal and clearance.
Debris/rubbish removal and clearance. - Jet washing with chemical cleaning agents to remove fungal stain or mould.
Jet washing with chemical cleaning agents to remove fungal stain or mould.
Gutter clearance and repair. - Carpentry.
Carpentry. - Lighting repairs.
Lighting repairs. - Re-plastering and plaster repairs.
Re-plastering and plaster repairs. - Rendering.
Rendering. - Window and door repairs.
Window and door repairs. - Tiling.
Tiling. - Carpeting and flooring.
Carpeting and flooring. - Plumbing.
Plumbing. - Building services maintenance.
Building services maintenance. - Repointing.
Repointing. - Removing paintwork: Can be removed by water washing, steam stripping, application of chemical paint removers, abrasive methods, hot air paint stripper, burning-off method (using a blowtorch).
Removing paintwork: Can be removed by water washing, steam stripping, application of chemical paint removers, abrasive methods, hot air paint stripper, burning-off method (using a blowtorch).
Repairing cracking or leaning walls. - Repairing decayed floorboards.
Repairing decayed floorboards. - Soft landings
Soft landings - Where it is possible, it is important that maintenance providers are involved in developing the brief for new buildings, and that they are properly instructed about the operation of new buildings before they are occupied.
Where it is possible, it is important that maintenance providers are involved in developing the brief for new buildings, and that they are properly instructed about the operation of new buildings before they are occupied.
There is often a significant gap between predicted and achieved performance that results in part from short-comings in briefing, design and construction and in part from poor operation. This problem is exacerbated by the almost complete separation of construction and operation.
The term soft landings refers to a strategy adopted to ensure the transition from construction to occupation is bump-free and that operational performance is optimised. See soft landings for more information.
Building owner's manual - O&M manual - The building owner's manual, or operation and maintenance manual (O&M manual), contains the information required for the operation, maintenance, decommissioning and demolition of a building.
The building owner's manual, or operation and maintenance manual (O&M manual), contains the information required for the operation, maintenance, decommissioning and demolition of a building.
The building owner's manual is prepared by the contractor with additional information from the designers (in particular the services engineer) and suppliers. It is a requirement that is generally defined in the preliminaries section of the tender documentation where its contents will be described, although there may be additional requirements regarding mechanical and electrical services in the mechanical and electrical specification.
See Building owner's manual - O&M manual for more information.
Building log book - Part L of the Building Regulations (conservation of fuel and power) requires that the building owner is issued with information about the building services to help them operate the building properly and efficiently. It is suggested that this is done by issuing a building log book to the building's facilities manager.
Part L of the Building Regulations (conservation of fuel and power) requires that the building owner is issued with information about the building services to help them operate the building properly and efficiently. It is suggested that this is done by issuing a building log book to the building's facilities manager.
Building log books are required for new buildings and for existing buildings where the services have changed. Whilst not a requirement of the Building Regulations, it is suggested that existing buildings would also benefit from a building log book.
See Building log book for more information. -
In-house or outsource maintenance - Maintenance can be carried out by an in-house team, or may be outsourced (or parts of it). On projects such as PFI projects, maintenance might be part of the contract that also includes design, construction and operation.
Maintenance can be carried out by an in-house team, or may be outsourced (or parts of it). On projects such as PFI projects, maintenance might be part of the contract that also includes design, construction and operation.
Depending on the size of an organisation, there can be many diverse decision makers when it comes to allocating responsibility for maintenance. However, one thing all decision makers have in common is that maintenance is seen as a service provision, perceived as a cost to the organisation. The internal struggle is how to demonstrate value from maintenance because without showing value, procurement will be determined on lowest cost. However, in the long-term, 'you get what you pay for.
See In-house or outsource maintenance for more information.
Facilities management - FM is concerned with the management of facilities in the built environment at both a strategic and a day-to day level to deliver operational objectives and to maintain a safe and efficient environment.
FM is concerned with the management of facilities in the built environment at both a strategic and a day-to day level to deliver operational objectives and to maintain a safe and efficient environment.
Whilst there has always been a need for facilities management, it has emerged, developed and grown as a profession in recent years, partly as a result of the increasing rate of change required in the built environment, but also due the trend for outsourcing services, and the introduction of procurement routes that include operation and maintenance in integrated supply contracts.
See Facilities management for more information. -
Masonry - Lime mortar.jpg
Lime mortar.jpg -
A mason is a person who builds with, or dresses, hard units such as brick, stone or block. The term masonry can be used to describe the trade of masons, work done by them, or the actual, stonework, brickwork or blockwork that they construct.
Masonry is generally used to form the walls and other solid elements of buildings and structures such as bridges, tunnels and so on. It may be load bearing, forming an integral part of the structure, or non-load bearing, such as a partition wall or cladding.
Generally the size of the units is suitable for being laid by one person, although, increasingly, masonry is delivered to site in prefabricated panels that are craned into position. Masonry is often formed by laying a number of interlocking units, bound together by mortar, however, dry set masonry relies on the friction between the units to prevent movement, and does not require mortar.
Masonry is very strong in compression, but less effective at resisting lateral loading or tension forces. Additional strength can be achieved by increasing the thickness of the masonry, by the addition of piers or buttresses, or by the incorporation of reinforcement.
Masonry walls may have complex constructions to optimise performance, that may include hollow sections in the masonry itself, a cavity between internal and external leaves of the wall, insulation, a vapour barrier and internal and external finishes and decoration.
However, generally masonry does not require finishing and decorating and is very durable, so is relatively inexpensive to maintain and repair. It tends to offer good thermal mass, high acoustic insulation and good resistance to fire.
Masonry tends to be heavy, and so requires strong foundations. It can be prone to frost damage, staining and disintegration of joints.
To find out about the cleaning of masonry, see How to clean masonry.
Mortar - Mortar is one of the oldest building materials, enabling large structures to be constructed from small, easy-to-handle components. It was used by the Romans, Greeks and Egyptians, and the oldest example may date back as far as 10,000 years in Israel (ref. Mortar Industry Association).
Mortar is one of the oldest building materials, enabling large structures to be constructed from small, easy-to-handle components. It was used by the Romans, Greeks and Egyptians, and the oldest example may date back as far as 10,000 years in Israel (ref. Mortar Industry Association).
It is composed from a mixture of a fine aggregate (typically sand), a binder (typically cement, but sometimes lime or a combination of lime and cement) and water. This combination creates a paste that is used in masonry construction as a bedding and adhesive to bind and fill the gaps between adjacent blocks of brick, concrete or stone.
Mortar is applied as a thick paste which sets hard as it cures. It creates a tight seal between bricks and blocks to prevent air and moisture entering into the construction. It can compensate for variations in brick or block size to produce an aesthetically-pleasing and structurally-sound construction. Generally, it is structurally weaker than the blocks or bricks it bonds, creating a sacrificial layer that is more easily repaired than defects would be in the bricks or blocks themselves.
Mortar is generally very durable and has a typical lifespan of between 20-30 years, after which repairs (or repointing) can be necessary to fill cracks or gaps that may begin to appear.
Mortar may be provided in its component parts and mixed on site, or factory-mixed. The two main types of factory-produced mortar are:
Wet ready-to-use mortar that requires no further mixing.
Dry ready-to-use mortar which requires the addition of water.
Factory-produced mortar is made under tightly-controlled conditions and provides:
Consistent quality, colour and strength. - Reduced mixing and labour costs.
Reduced mixing and labour costs. - Reduced wastage.
Reduced wastage. - Guaranteed specification.
Guaranteed specification. - Improved site health and safety.
Improved site health and safety. - For the different types of mortar, see Types of mortar.
For the different types of mortar, see Types of mortar.
The profile of mortar joints (pointing) can be varied depending on exposure or to create a specific visual effect. The most common profiles are; flush (rag joint), bucket handle, weather struck, weather struck and cut, and recessed.
A wide range of colours are available to match or contrast with the surrounding bricks or blocks, or to match existing mortar. Pigments are specified according to BS EN 12878:2014 Pigments for the colouring of building materials based on cement and/or lime. Specifications and methods of test.
A range of admixtures can be included in mortar, such as plasticisers, bonding agents, and waterproofing. These can be specified according to BS EN 934-3:2009+A1:2012 Admixtures for concrete, mortar and grout. Admixtures for masonry mortar. Definitions, requirements, conformity and marking and labelling.
Mortar must have good workability to ensure there are no air pockets which might prevent proper bonding. Plasticisers can improve workability by entraining very small air bubbles in the mix. Alternatively, the addition of lime can improve the workability of mortar.
Where porous bricks or blocks are being laid, the mortar may dry quickly, preventing proper levelling and so preventing a good bond from being formed. This can be countered by laying shorter lengths or by limited wetting.
Binding agent - A binding agent, or binder, is a material used to form materials into a cohesive whole, as a means of providing structural stability. Binding agents harden chemically or mechanically, and in the process bond fibres, filler powder and other substances together.
A binding agent, or binder, is a material used to form materials into a cohesive whole, as a means of providing structural stability. Binding agents harden chemically or mechanically, and in the process bond fibres, filler powder and other substances together.
Binding agents have been commonly used in construction for a very long time; for example, the use of straw and natural fibres to strengthen clay in wattle-and-daub construction. A very common binding agent used in contemporary construction is cement, which is used to make concrete. Other common examples include bitumen binder which is used for asphalt pavements, and clay for binding bricks.
Hydraulic binding agents are often used in underground and underwater engineering projects. On mixing with water they continue to preserve and increase their strength. Examples include; Portland cement, pozzolanic cement, blast-furnace cement, alumina and expanding cement, hydraulic lime, and so on.
Air-entrained binding agents harden and maintain their strength after mixing in air rather than water. Examples include; gypsum cement, magnesium cement, air-hardening lime, and so on.
Acid-resistant binding agents can maintain their strength after mixing in air while also in contact with acids, and form various kinds of acid-resistant cement, such as silicon fluoride cement, quartz cement, and so on.
Binding agents can also be 'organic', where they are of organic origin, such as asphalt, bitumen, pitch, polyvinylacetate, resins, and so on. Under the influence of physical or chemical processes they transition from a plastic state to a hard state.
Durability Guaranteed - Pulhamite Rockwork - Its conservation and repair, Published by Historic England in 2008, defines a binder as: The medium or vehicle that binds together the particles of aggregate in a mortar, render or concrete, or the pigments and fillers in a coating (in a mortar or render the binder is usually lime or cement). The binder coats each particle and fills the voids between them, and it is the drying or curing of the binder that causes a mortar or coating to set. Its drying or curing properties and the proportion of binder to aggregate are very important in determining the durability of a mortar.
NB: The use of 'mechanical' binders refers to bond stones in masonry, and tie beams in timber framing.
Introduction - Pavements are a form of exterior surface covering, typically raised and used by pedestrians, running parallel to, and on either side of a road. They provide an area that is separated from, and so protected from vehicular traffic. However, the term can also be used to refer to other paved areas, such as pedestrianised streets, patios, courtyards, driveways, and so on.
Pavements are a form of exterior surface covering, typically raised and used by pedestrians, running parallel to, and on either side of a road. They provide an area that is separated from, and so protected from vehicular traffic. However, the term can also be used to refer to other paved areas, such as pedestrianised streets, patios, courtyards, driveways, and so on.
Pavements can be constructed using asphalt, concrete, flagstone, cobblestone, artificial stone, bricks, tiles and timber.
The term paver or paviour (pavior in the USA) refers to a paving stone, tile, brick or piece of concrete used to form a pavement surface. They are usually laid to a fall of 1:60 or more to drain water to one or both sides. They are usually built to a minimum width of 1.2 m where this is possible.
Suspended ceilings are secondary ceilings suspended from the structural floor slab above, creating a void between the underside of the floor slab and the top of the suspended ceiling. The gap between a suspended ceiling and the structural floor slab above is often between 3 to 8 inches which is why they are often referred to as dropped ceilings or false ceilings.
Suspended ceilings are very popular in commercial properties as they provide a useful space for concealing unsightly wires and installations that otherwise would alter the interior appearance of the building.
The space gained through installed a suspended ceiling has proved useful for distribution of heating, ventilation and air conditioning (HVAC) services and plumbing and wiring services, as well as providing a platform for the installation of speakers, light fittings, wireless antenna, CCTV, fire and smoke detectors, motion detectors, sprinklers and so on.
Buildings should be designed to offer an acceptable level of fire safety and to minimise risks from heat and smoke.
The objective is to reduce to acceptable levels the potential for death or injury to the occupants of a building and others who may become involved, such as the fire and rescue service, as well as to protect contents and ensure that as much as possible of a building can continue to function after a fire. The risk to adjoining properties also needs to be considered, as well as possible environmental pollution.
The main design options for ensuring fire safety are:
Prevention: Controlling ignition and fuel sources so that fires do not start.
Communications: If ignition occurs, ensuring occupants are informed and any active fire systems are triggered.
Escape: Ensuring that occupants of buildings and surrounding areas are able to move to places of safety.
Containment: Containing fire to the smallest possible area, limiting the amount of property likely to be damaged and the threat to life safety.
Extinguishment: Ensuring that fire can be extinguished quickly and with minimum consequential damage.
Sprinklers are designed to extinguish small fires or contain growing fires until the fire and rescue service arrives.
Part B of the building regulations requires the installation of sprinklers under certain circumstances, such as new residential blocks of more than 30m in height and uncompartmented areas of shops or self storage buildings of more than 2000 square metres. They can also be used as a compensatory feature to address a specific fire hazard.
Sprinkler systems distribute water to sprinkler heads which spray water into spaces as required. They are a well-established technology and have demonstrated their reliability and effectiveness in protecting life and property over a long period.
It is thought that the oldest sprinkler system in Britain was fitted in 1812 in the Theatre Royal on Drury Lane. Traditionally, sprinkler systems have been used in commercial and industrial properties, but they are now available for a wide range of applications, including domestic buildings. More than 40 million sprinklers are fitted world-wide each year (Ref British Automatic Fire Sprinkler Association).
The British Automatic Fire Sprinkler Association suggest that losses from fires in buildings protected by sprinklers are one tenth of those in unprotected buildings.
Individual sprinklers operate when activated by their own heat detector, and then spray water onto the fire. They typically cover an area of 9 sq. m. They can be placed within occupied spaces, or in concealed spaces such as floor ducts to prevent fires from growing unnoticed.
Sprinkler systems can be: -
Wet installations. - Alternate wet and dry installations.
Alternate wet and dry installations. - Dry installations.
Dry installations. - Tail-end alternate systems.
Tail-end alternate systems. - Pre-action installations.
Pre-action installations. - Deluge installations.
Deluge installations. - System zones.
System zones. - Sprinklers themselves can be:
Sprinklers themselves can be: -
Conventional and spray type sprinklers. - Ceiling, recessed and concealed type sprinklers.
Ceiling, recessed and concealed type sprinklers. - Side wall type sprinklers.
Side wall type sprinklers. - Early Suppression Fast Response (ESFR) sprinklers.
Early Suppression Fast Response (ESFR) sprinklers.
Enhanced Protection Extended Coverage (EPEC) sprinklers.
According to The Impact of Automatic Sprinklers on Building Design, an independent report produced by WSP, sponsored by the Business Sprinkler Alliance (BSA), automatic sprinklers:
Typically only operate in areas where fire is present allowing adjacent rooms or areas to remain unaffected.
Reliability of discharge in the presence of fire is 98 to 99.8%, and discharge in the absence of fire is rare.
Have an 80-95% probability of being successful.
Can be designed to conceal pipes, and the availability of decorative sprinkler heads allows them to be matched with the interior of the space.
In June 2018 it was announced that the Scottish government was introducing legislation to make sprinklers compulsory in new social housing.
In March 2019 the Local Government Association (LGA) called for tougher rules on sprinklers to guarantee fire safety in high-rise buildings and care homes. Ref https://www.local.gov.uk/about/news/tougher-sprinkler-rules-needed-councils-and-fire-authorities-urge
In September 2019, following the Grenfell Tower fire, it was announced that the government was consulting on reducing the building height beyond which sprinklers are required from 30 metres to 18 metres. The consultation will run until 28 November 2019. In addition, a new Protection Board has been created to provide reassurance to residents of high-risk residential blocks that any risks are identified and acted upon. The Board will operate until a new building safety regulator is established to oversee the new regulatory regime for buildings and legislation on a new building safety regime is introduced. Ref https://www.gov.uk/government/news/sprinkler-review-for-high-rise-homes
On 2 April 2020, in response to the Building a Safer Future consultation, Housing Secretary Robert Jenrick MP announced steps to introduce mandatory sprinkler systems and consistent wayfinding signage in all new high-rise blocks of flats over 11 metres tall. The government will legislate for these reforms through the Building Safety Bill. For more information see: Government response to the Building a Safer Future consultation.
Dry risers are used to supply water within buildings for fire-fighting purposes. The provision of a built-in water distribution system means that fire fighters do not need to create their own distribution system in order to fight a fire and it avoids the breaching of fire compartments by running hose lines between them.
Dry risers do not contain water when they are not being used, but are charged with water by fire service pumping appliances when necessary. This is as opposed to wet risers, which are permanently charged with water.
Dry risers have an inlet connector at rescue service vehicle access level and landing valves at locations on each floor. Part B of the building regulations (Fire Safety) requires that fire mains are provided in buildings that are more than 18 m tall. In buildings less than 50m tall, fire mains can be either dry or wet risers, however, where a building extends to more than 50 m above the rescue service vehicle access level, wet risers are necessary as the pumping pressure required to charge the riser is higher than can be provided by a fire service appliance, and to ensure an immediate supply of water is available at high level.
Each inlet connector must be within 18 m of a fire service appliance access. Inlet connectors are typically contained in accessible, but secure enclosures on the external face of buildings and are identified as a dry riser inlet.
Dry risers themselves should be within fire-fighting shafts, and where necessary in protected escape stairs. Dry riser outlets, or landing valves, may be located in protected lobbies, stairs or enclosures where these are available.
At the top of dry-riser pipework an air valve is provided to allow air in the dry riser to escape when the riser is charged with water. There is often also a roof-level testing outlet.
Dry risers should be inspected and tested regularly to ensure equipment is functioning correctly and ready for use. Problems can be very serious in the event of a fire, and are typically caused by vandalism or theft, blockages or pipework failure or by connection failure or outlets being open.
Use of the term air conditioning (AC) can be confusing.
In some of the strictest definitions, air conditioning is used to describe systems that control the moisture content of air, that is, its humidity. This can include humidification and dehumidification. Humidity control can be important for; the comfort of building occupants, to reduce the incidence of condensation (both surface and interstitial), for specialist environments such as swimming pools, and where the protection of sensitive items requires particular conditions.
However, dehumidification of air is generally achieved by cooling. As the temperature of air falls, it is less able to 'hold' moisture, that is, saturation water vapour density falls, and so relative humidity rises. When relative humidity reaches 100%, the air will be saturated. This is described as the 'dew point'. If the air continues to cool, moisture will begin to condense, dehumidifying the air.
This means that humidity control and cooling are often considered together as air conditioning. Cooling and dehumidification are important contributors to thermal comfort. This is because the ability to perspire, and so to lose heat by evaporation from the skin, is limited by the humidity of the air.
As a result, remaining cool is dependent on both temperature and humidity (as well as a number of other factors, see Thermal comfort for more information). A combination of reduced air temperature, and reduced humidity helps people to remain cool.
The cooling of air alone, often described as air conditioning is more correctly referred to as comfort cooling. However, because it cools the air, comfort cooling may include some incidental dehumidification.
Other definitions of air conditioning describe it as the process of conditioning supply air to:
Regulate its humidity. - Regulate its quality (through filtration).
Regulate its quality (through filtration). - Regulate its temperature.
Regulate its temperature. - CIBSE Guide B. Heating, Ventilating, Air Conditioning and Refrigeration suggests that:
CIBSE Guide B. Heating, Ventilating, Air Conditioning and Refrigeration suggests that:
Air conditioning involves full control over the humidity within the conditioned space as well as temperature control. CIBSE suggest that 'close control air conditioning' might be defined as the control of temperature to within 1K and relative humidity to within 10%. This requires a complex process of dehumidification and cooling, reheating and humidification.
The Department for Communities and Local Government (CLG) guide, Improving the energy efficiency of our buildings, A guide to air conditioning inspections for buildings, December 2012 suggests that an air conditioning system is defined as a combination of all components required to provide a form of air treatment in which the temperature is controlled, or can be lowered, and includes systems which combine such air treatment with the control of ventilation, humidity and air cleanliness.
This includes fixed, self-contained systems, such as split systems and centralised systems. Mechanical ventilation systems that provide no mechanical cooling, but serve spaces that are cooled by other means are included. Any components contained in air conditioning systems that are only intended to provide heating are excluded.
Air handling unit AHU - Air handling units (AHU, sometimes referred to as air handlers) form part of the heating, ventilating and air conditioning system (HVAC) that supplies, circulates and extracts air from buildings.
Air handling units (AHU, sometimes referred to as air handlers) form part of the heating, ventilating and air conditioning system (HVAC) that supplies, circulates and extracts air from buildings.
Air handling units can be supplied in a range of sizes, and with a variety of capabilities, but typically they comprise an insulated box that forms the housing for; filter racks or chambers, a fan (or blower), and sometimes heating elements, cooling elements, sound attenuators and dampers (that can be operated manually or automatically to regulate or prevent specific air flows). In some situations, such as in swimming pools, air handling units might include dehumidification.
Heating and / or cooling can be generated within the unit itself, or can be provided by connection to the buildings boilers or chillers.
Generally, air handling units will be connected to the ductwork within the building that supplies air to and extracts air from the interior, but they can be used to supply and extract air direct to a space, or they may be located on a roof (rooftop units or RTU).
Air handling units that consist of only a fan and a heating or cooling element, located within the space they are serving, may be referred to as fan coil units (FCU).
Air handling units can be used to re-circulate a proportion of stale air within a building, mixing this with fresh air to reduce the amount of air conditioning that is required. They can also include heat recovery, recovering heat from return air and using it to warm the supply air.
Fans may be single speed, may have a range of set speeds, or may be variable frequency drive. Flow rates may also be controlled by inlet vanes or outlet dampers.
Air handling units generate noise (and vibration) which can be disruptive, and this can be compounded where ductwork passes between acoustically separate spaces. In this case, acoustic attenuators might be used. In addition, vibration can be generated. This vibration can be isolated by inserting flexible sections between the unit and ductwork and by isolating the unit from the building structure.
Where air handling units are located outside buildings, they can be the source of complaints by neighbours because of the noise and vibration they generate and sometimes because of odours they expel (typically where they are serving kitchens). It is important that these units are properly designed, installed and maintained to minimise this disturbance.
Wet systems, that include water evaporative cooling, can present a hazard to health. Businesses using such systems are required to carry out a risk assessment and put in place procedures to ensure there is no risk to public health.
Ductwork, ducts, or ducting, are conduits, or tubes, that typically form part of a ventilation system, used to convey air throughout a building. An example of a simple elementary duct is a fireplace chimney, used to convey smoke to the outside. Hard pipes used to transfer water or gas are not classed as ductwork.
Duct design involves planning (laying out), sizing, optimising, and detailing. Ductwork should be among the first items to be considered when designing a new building because of its importance in the overall utility of the building, and the need to integrate complex duct routes with other elements of the overall design. This can be particularly difficult where structural elements pass through building services spaces, such as the downstands of beams, or where ducts have to pass through other elements of the building.
Ducts can be fabricated from a range of materials:
Galvanised mild steel: This is the most common material used as the zinc coating prevents rust forming.
Aluminium: This is lightweight and quick to instal. Custom shapes can be easily fabricated as required by the particular design.
Polyurethane and phenolic foam panels: These are manufactured with aluminium facings on both sides.
Fibreglass: This provides built-in thermal insulation and sound is absorbed by the interior surface.
Flex ducts: These are typically made of flexible plastic over a metal wire coil.
Ductwork layouts may be very complex, involving a number of supply and return ducts, that branch to all parts of a building. Typically Heating Ventilation and Air Conditioning (HVAC) ducting will run through voids above a suspended ceiling, supplying and extracting air from the occupied spaces below through diffuser grilles. Air may be drawn or blown through the ducts by fans or by air handling units.
Duct sizes are calculated based on the relationship between air volume, size, air velocity and resistance. The requirements for the provision of air within buildings is set out in Part F of the building regulations, Ventilation.
Air handling units generate noise (and vibration) which can be disruptive, and this can be compounded where ductwork passes between acoustically separate spaces. In this case, acoustic attenuators might be included in the air handling unit or ductwork. In addition, vibration can be generated. This vibration can be isolated by inserting flexible sections between air handling units and ductwork and by isolating the unit from the building structure.
Other components that can be incorporated in ducting systems include:
Distribution boxes to redirect airflow as required. - Take-offs, which allow a small portion of the main ducts flow to be diverted into branch ducts.
Take-offs, which allow a small portion of the main ducts flow to be diverted into branch ducts.
Volume control dampers, which allow for the adjustment of air flow, and may be manual or automatic.
Smoke and fire dampers where the ductwork passes between fire compartments.
Turning vanes where there are changes of direction and help minimise turbulence and resistance by guiding the air.
Access points for cleaning and maintenance. - Before approval, ductwork should be tested to confirm it is adequately sealed.
Before approval, ductwork should be tested to confirm it is adequately sealed.
NB The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, defines a duct as: the structure, trunking, or casing, with any apertures, enclosing a passage, other than a flue, used solely for conveying air, gases, or refuse.
A combustion appliance is an apparatus where fuel is burned to generate heat for space heating, water heating, cooking or other similar purpose. The appliance does not include systems to deliver fuel to it or for the distribution of heat. Typical combustion appliances are boilers, warm air heaters, water heaters, fires, stoves and cookers.
A boiler is a piece of technical apparatus in which fuels are oxidised to generate thermal energy, which is transferred to water or steam. Boilers are typically used to heat water to feed heating systems or to supply hot water, or both. Boilers are most commonly fuelled by:
Mains gas - Liquid petroleum gas (LPG).
Liquid petroleum gas (LPG). - Wood.
Wood. - Coal.
Coal. - Oil.
Oil. - Electricity.
Electricity. - There are a very wide range of boilers available depending on; size, fuel type, efficiency and application, and ranging from compact units used for domestic heating, to very large boilers used for industrial processes. For more information, see:
There are a very wide range of boilers available depending on; size, fuel type, efficiency and application, and ranging from compact units used for domestic heating, to very large boilers used for industrial processes. For more information, see:
Biomass boiler - CHP boiler
CHP boiler - Types of domestic boiler
Types of domestic boiler - Boiler efficiency
Boiler efficiency - Condensing boiler
Condensing boiler - Types of heating system.
Types of heating system. - Thermostat.
Thermostat. - An automatic feed boiler is a boiler with fully automated fuel supply.
An automatic feed boiler is a boiler with fully automated fuel supply.
Improved efficiency of new boilers - Heating accounts for a large portion of household expenses, especially during the winter. But if your energy costs are higher than normal, it may be due to an aging boiler. Boilers gradually become less efficient over time and often require more maintenance.
Heating accounts for a large portion of household expenses, especially during the winter. But if your energy costs are higher than normal, it may be due to an aging boiler. Boilers gradually become less efficient over time and often require more maintenance.
Replacing an old boiler with a new one means improved efficiency and lower emissions as a result. The Energy Saving Trust estimates that new boiler installations can potentially save households hundreds of pounds a year in energy costs alone.
Installations that meet safety regulations - All boiler installations must meet building and safety regulations. All boiler engineers must deliver professional new boiler installations that meet all safety requirements as established by the government. Most engineers are Gas Safe Registered and properly insured with public liability insurance.
All boiler installations must meet building and safety regulations. All boiler engineers must deliver professional new boiler installations that meet all safety requirements as established by the government. Most engineers are Gas Safe Registered and properly insured with public liability insurance.
Boiler replacement costs vary, as every home has different heating requirements. Upfront costs may seem hefty, but replacing an aging boiler is well worth the investment in the long term. A more efficient boiler means greater energy savings.
Request a consultation - If youre considering installing a new boiler, contact a boiler engineer for a consultation and a written estimate for your new boiler. In some cases, they will also give recommendations such as a power flush to remove any sludge and debris that could be affecting how your boiler runs.
If youre considering installing a new boiler, contact a boiler engineer for a consultation and a written estimate for your new boiler. In some cases, they will also give recommendations such as a power flush to remove any sludge and debris that could be affecting how your boiler runs.
There is an extensive process to assess your entire central heating system and determine the work involved. This allows a more accurate quote to be provided, and the recommendation of a new boiler for your living space.
Energy cost is: The total energy cost from space heating, water heating, ventilation and lighting, less the costs saved by energy generation as derived from SAP calculations and assumptions. This is measured in /year using constant prices based on average fuel prices for 2012 (which input into the 2012 SAP calculations) and do not reflect subsequent changes in fuel prices. Energy costs for each dwelling are based on a standard occupancy and a standard heating regime.
Carbon fibre is fibre made of carbon. But, these fibres are only a base. What is commonly referred to as carbon fibre is a material consisting of very thin filaments of carbon bound together with plastic polymer resin by heat, pressure or in a vacuum. The resulting composite material both strong and lightweight.
Like many fabrics, the strength of carbon fibre is in the weave. The more complex the weave, the more durable the composite will be. It is helpful to imagine a wire screen that is interwoven with another screen at an angle, and another at a slightly different angle, and so on, with each wire in each screen made of carbon fibre strands. Imagine this mesh of screens drenched in liquid plastic, and then pressed or heated until the material fuses together. The angle of the weave, as well as the resin used with the fibre, will determine the strength of the overall composite. The resin is most commonly epoxy, but can also be thermoplastic, polyurethane, vinyl ester, or polyester.
Alternatively, a mold may be cast and the carbon fibres applied over it. The carbon fibre composite is then allowed to cure, often by a vacuum process. In this method, the mold is used to achieve the desired shape. This technique is preferred for uncomplicated forms that are needed on demand.
Carbon fibre material has a wide range of applications, as it can be formed at various densities in limitless shapes and sizes. Carbon fibre is often shaped into tubing, fabric, and cloth, and can be custom-formed into any number of composite parts and pieces.
It is common to find carbon fibre in:
Aeronautics and aerospace industries - Oil and gas industry
Oil and gas industry - Unmanned aerial vehicles
Unmanned aerial vehicles - Formula 1 cars
Formula 1 cars - Satellites
Satellites - Musical instruments
Musical instruments - Furniture
Furniture - Art
Art - Structural elements of buildings
Structural elements of buildings - Bridges
Bridges - Wind turbine blades
Wind turbine blades - Carbon fibre is an incredibly useful material used in composites, and it is likely to continue to grow manufacturing market share. As more methods of producing carbon fibre composites economically are developed, the price is likely to continue to fall, and more industries will take advantage of this unique material.
Carbon fibre is an incredibly useful material used in composites, and it is likely to continue to grow manufacturing market share. As more methods of producing carbon fibre composites economically are developed, the price is likely to continue to fall, and more industries will take advantage of this unique material.
History of carbon fibre - The 20th century saw a roller coaster ride in the demand for carbon fibre. Threats to peace increased the demand for carbon fibre for defense purposes in the middle of the century. A downturn in defense needs then resulted in a reduction in production of carbon fibre toward the close of the century. By the beginning of the 21st century, new applications and new markets sent the production of carbon fibres on an upswing. Despite the downturn in 2007-2008, worldwide demand increased to approximately 40,000 metric tons in 2010.
The 20th century saw a roller coaster ride in the demand for carbon fibre. Threats to peace increased the demand for carbon fibre for defense purposes in the middle of the century. A downturn in defense needs then resulted in a reduction in production of carbon fibre toward the close of the century. By the beginning of the 21st century, new applications and new markets sent the production of carbon fibres on an upswing. Despite the downturn in 2007-2008, worldwide demand increased to approximately 40,000 metric tons in 2010.
Carbon fibres have revolutionised the technology of materials. The National Academy of Engineering voted carbon fibres one of the 20 top engineering achievements of the 20th century and the American Chemical Society named the development of high performance carbon fibres a National Historic Chemical Landmark in September 2003.
Formwork is the term used for the process of creating a temporary mould into which concrete is poured and formed. Traditional formwork is fabricated using timber, but it can also be constructed from steel, glass fibre reinforced plastics and other materials.
While formwork is a broad term that is used in relation to the forming process using a wide variety of materials, shuttering is a term that is often used to refer to the process of using plywood to form the mould.
Shuttering is perhaps the most popular type of formwork and is normally constructed on site using timber and plywood. A special grade of plywood is necessary for shuttering, and it must be water-resistant. It is easy to produce, although it can be time consuming for larger structures. It is used when the labour costs are lower than the cost of producing re-usable formwork from materials such as steel or plastic. It also has the advantage of beingat a significant amount of concrete can be poured at once.
Simple plank shuttering can be used for the construction of a path or hardstanding. The planks should be trimmed so they are level with the top surface of the slab, allowing a tidy concrete finish to be achieved.
Formwork specifications - When selecting formwork, the type of concrete and temperature of the pour are important considerations as they both effect the pressure exerted.
When selecting formwork, the type of concrete and temperature of the pour are important considerations as they both effect the pressure exerted.
The formwork sides must be capable of resisting the hydrostatic pressure of the wet concrete which will diminish to zero within several hours depending on the rate of setting and curing.
The formwork base or soffit must be capable of resisting the initial dead load of the wet concrete and the dead load of the dry set concrete.
Once the concrete has gained sufficient strength the formwork can be struck (removed). A minimum value of 5 N/mm2 is recommended in all cases when striking vertical formwork as so not to damage the permanent concrete in the process.
High quality workmanship and inspection are necessary to ensure a high standard and appearance of the resulting concrete structure.
Both shuttering and formwork in its various forms will be supported by falsework. This refers to poles, stabilisers, or other units that keep the shuttering or formwork in place as the concrete dries. For more information, see Falsework.
Beam formwork - Formwork for beams takes the form of a three-sided box which is supported and propped in the correct position and to the desired level. The removal time for the formwork will vary with air temperature, humidity and consequent curing rate. Typical striking times are as follows (using air temperature of 7-16 C):
Formwork for beams takes the form of a three-sided box which is supported and propped in the correct position and to the desired level. The removal time for the formwork will vary with air temperature, humidity and consequent curing rate. Typical striking times are as follows (using air temperature of 7-16 C):
Beam sides: 9-12 hours. - Beam soffits: 8-14 days.
Beam soffits: 8-14 days. - Beam props: 15-21 days.
Beam props: 15-21 days. - Column formwork
Column formwork - This consists of a vertical mould of the desired shape and size of the column to be poured. As a means of keeping the formwork material thickness to a minimum, horizontal steel or timber clamps (or yokes) are used at equal centres for batch filling and at varying centres for filling that is completed in one pour.
This consists of a vertical mould of the desired shape and size of the column to be poured. As a means of keeping the formwork material thickness to a minimum, horizontal steel or timber clamps (or yokes) are used at equal centres for batch filling and at varying centres for filling that is completed in one pour.
The head of the column formwork can be used to provide support for the beam formwork, but while this gives good top lateral restraint it can make the formwork complex. Alternatively, the column can be cast to the underside of the beams. Later on, a collar of formwork can be clamped around the cast column to complete the casting and support the incoming beam formwork.
Plastic formwork - Re-usable plastic formwork is generally used for quick pours of concrete. The formwork is assembled either from interlocking panels or from a modular system and is used for relatively simple concrete structures. It is not as versatile as timber formwork due to the prefabrication requirements and is best suited for lost-cost, repetitive structures such as mass housing schemes.
Re-usable plastic formwork is generally used for quick pours of concrete. The formwork is assembled either from interlocking panels or from a modular system and is used for relatively simple concrete structures. It is not as versatile as timber formwork due to the prefabrication requirements and is best suited for lost-cost, repetitive structures such as mass housing schemes.
Stay-in-place structural formwork is generally assembled on site using prefabricated fibre-reinforced plastic. It is used for concrete columns and piers and stays in place, acting as permanent axial and shear reinforcement for the structural member. It also provides resistance to environmental damage for both the concrete and reinforcing bars.
Proprietary systems are used to support vertical formwork while concrete cures, consisting of a series of tubes and ties.
https://www.designingbuildings.co.uk/wiki/File:Plastic-formwork.png -
Plywood (sometimes referred to simply as ply) is an engineered sheet timber product that is widely used for construction purposes. It is manufactured from three or more thin layers of wood veneer, or plies, that are glued together to form a thicker, flat sheet. It is economical, capable of being produced to precise dimensions and is relatively resistant to warping and cracking.
Some of the most common uses of plywood include:
Light partition or external walls. - Formwork.
Formwork. - Furniture.
Furniture. - Flooring.
Flooring. - Structural systems.
Structural systems. - Light doors and shutters.
Light doors and shutters. - Types of plywood include:
Types of plywood include: -
Structural plywood: Used in permanent structures where high strength is needed, such as beams, formwork and bracing panels.
External plywood: Used on exterior surfaces where a decorative or aesthetic finish is important.
Internal plywood: Used for aesthetic finishing of non-structural applications such as wall paneling and ceilings.
Marine plywood: Water resistant plywood that is used in shipbuilding and in parts of buildings where there may be high moisture content, such as roofing or bathrooms.
Manufacturing process - Plywood is manufactured from softwoods (such as Douglas fir, pine and redwood), hardwoods (such as ash, maple and mahogany), or a combination of both.
Plywood is manufactured from softwoods (such as Douglas fir, pine and redwood), hardwoods (such as ash, maple and mahogany), or a combination of both.
The timber used to make plywood is prepared by steaming or dipping in hot water. It is then peeled into thin plies of between 1-4 mm by a lathe machine. It is then formed into large sheets.
Plywood consists of the face (the surface that is visible after installation), the back, and the core (which lies between the face and the back). The plies are glued together using a strong adhesive, usually a phenol or urea formaldehyde resin.
Each layer of ply is oriented with its wood grain perpendicular to the adjacent layer, rotated up to 90-degrees to one another. This is called cross-graining and it is this that distinguishes plywood from laminated veneer lumber (LVL). In LVL, the direction of the plies is the same, whereas in plywood, the direction of the plies alternates. It is usual to have an odd number of plies so that the sheet is balanced and this helps to reduce warping.
Cross-graining reduces the tendency of the plywood to split when nailed at the edges. It also reduces expansion and shrinkage, which improves its dimensional stability, and it gives panels consistent strength in all directions.
It is possible to engineer composite plywood when thick sheets are required. In this case, a core of solid timber pieces or particleboard is used, with a wood veneer for the face and back.
The durability of the face and back veneers can be improved by the addition of a thin outer layer that resists moisture, abrasion and corrosion, as well as making it easier to apply paint and dye. Some of the materials that can be used include plastic, resin-impregnated paper, fabric, Formica, and metal.
Properties - Plywood has several properties that make it a useful and popular construction material.
Plywood has several properties that make it a useful and popular construction material.
High strength - Plywood combines the structural strength of the timber from which it is manufactured, with the properties obtained from its laminated design. Cross-graining allows the sheet to resist splitting and provides uniform strength for increased stability.
Plywood combines the structural strength of the timber from which it is manufactured, with the properties obtained from its laminated design. Cross-graining allows the sheet to resist splitting and provides uniform strength for increased stability.
High panel shear - The odd number of veneer layers that comprise plywood mean that it is resistant to bending. By increasing the panel shear of plywood, it can be used in bracing panels and fabricated beams.
The odd number of veneer layers that comprise plywood mean that it is resistant to bending. By increasing the panel shear of plywood, it can be used in bracing panels and fabricated beams.
Flexibility - Plywood can be manufactured to fit a wider range of requirements than cut timber. Veneer thicknesses can vary from a few millimetres to several inches, and the number of veneers used can be increased as required in terms of strength.
Plywood can be manufactured to fit a wider range of requirements than cut timber. Veneer thicknesses can vary from a few millimetres to several inches, and the number of veneers used can be increased as required in terms of strength.
Moisture resistance - Plywood is relatively resistant to moisture and humidity due to the type of adhesive that is used in the binding process. This can make it suitable for exterior use such as cladding, sheds, concrete formwork and in marine construction. The veneers are prevented from warping, shrinking or expanding on exposure to water and temperature by the cross lamination.
Plywood is relatively resistant to moisture and humidity due to the type of adhesive that is used in the binding process. This can make it suitable for exterior use such as cladding, sheds, concrete formwork and in marine construction. The veneers are prevented from warping, shrinking or expanding on exposure to water and temperature by the cross lamination.
Chemical and fire resistance - Plywood can be treated with preservatives which make it resistant to corrosion when exposed to chemicals. Chemical coatings can also increase plywoods resistance to fire.
Plywood can be treated with preservatives which make it resistant to corrosion when exposed to chemicals. Chemical coatings can also increase plywoods resistance to fire.
Impact resistance - Cross lamination gives plywood high tensile strength which makes it capable of withstanding overloading by up to twice its designated load. This makes it suitable for use in flooring systems and formwork.
Cross lamination gives plywood high tensile strength which makes it capable of withstanding overloading by up to twice its designated load. This makes it suitable for use in flooring systems and formwork.
Insulation - Plywoods high thermal and sound insulation qualities make it suitable for flooring, ceilings, roofing and wall cladding.
Plywoods high thermal and sound insulation qualities make it suitable for flooring, ceilings, roofing and wall cladding.
A dimension is a derived unit used to measure a physical quantity such as length, width, height, distance, area, volume, mass and time.
Some of these units, such as area, can be obtained by the multiplication of two other dimensions, so for example (a x b) gives the area ab. Other measurements such as volume can be established by combining three linear measurements. The volume of say, a cylinder may be given by multiplying the area by the height (a x b x h).
A straight line has one dimension; an area has two dimensions and a volume has three.
Measuring velocity requires combining dimensions of length and time. Measuring force also requires combining various dimensions.
In construction, the dimensions most used are those concerning length to provide other dimensions of height, distance, area and volume. Measuring time is also important in construction, as is mass.
Dimensions are critical for co-ordinating building components and ensuring each fits correctly in its allocated place in a construction. Dimensionally co-ordinated products allow designers to select items which they can be confident will fit together (co-ordinate) dimensionally with the structure and other components to accepted tolerances.
Measurements are often included on drawings to give an overall understanding of size, or by wave of instruction to help workers setting out a project or manufacturing components.
Introduction - Heat transfer is the process of thermal exchange between different systems. Generally the net heat transfer between two systems will be from the hotter system to the cooler system.
Heat transfer is the process of thermal exchange between different systems. Generally the net heat transfer between two systems will be from the hotter system to the cooler system.
Heat transfer is particularly important in buildings for determining the design of the building fabric, and for designing the passive and active systems necessary to deliver the required thermal conditions for the minimum consumption of resources.
Very broadly, the mechanisms of heat transfer can be described as:
Conduction. - Convection.
Convection. - Radiation.
Radiation. - Phase change.
Phase change. - The thermal behaviour of a system is a function of the dynamic relationship between these mechanisms.
The thermal behaviour of a system is a function of the dynamic relationship between these mechanisms.
Conduction - Conduction is the diffusion of internal heat within a body as a result of a temperature difference across it.
Conduction is the diffusion of internal heat within a body as a result of a temperature difference across it.
This is particularly important in buildings where there may be a temperature difference between the inside and outside of a building, such as in a heated building during winter. Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.
For building materials it is sometimes thought that conductivity is expressed by the U-Value, however, U-values are the reciprocal of the sum of the thermal resistances of a body plus its inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.
Conduction can be inhibited by insulating materials which have a high thermal resistance and so help reduce heat transfer between the inside and outside. See Insulation for more information.
An insulating effect can also be achieved by the thermal mass of building components. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. In building design, this can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems.
Convection - Convection is the movement of a fluid, such as the air, by advection and diffusion. This is a very important mechanism in the design of buildings, where air movement is necessary to:
Convection is the movement of a fluid, such as the air, by advection and diffusion. This is a very important mechanism in the design of buildings, where air movement is necessary to:
Moderate internal temperatures. - Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Improve the comfort of occupants. - Convection is also a heat transfer mechanism, resulting from the movement of air of different temperatures.
Convection is also a heat transfer mechanism, resulting from the movement of air of different temperatures.
Air movement in buildings can be 'forced' (for example driven by fans), or 'natural' resulting from pressure differences from one part of a building to another. Natural air movement can be either wind driven, or buoyancy driven. For more information see: Natural ventilation.
Accurately predicting the movement of air within buildings is extremely complicated and can require the use of computational fluid dynamics (CFD) modelling software. See CFD for more information.
See convection for more information. -
NB: Fluids can also be used to transfer heat within a building by 'mass transfer', for example by the flow of a refrigerant, chilled water or hot water around a building to provide heating or cooling.
Radiation - All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
The range of terrestrial temperatures experienced within the built environment is relatively small, and relative to the temperature of the sun this range is 'cold' and so radiating at a 'long' wavelength compared to the sun. This anomaly allows us to categorise thermal radiation as short-wave solar radiation and terrestrial or long wave infra-red radiation. Surfaces in the built environment will tend to absorb solar radiation and emit long wave infra-red radiation.
This difference also produces effects such as the greenhouse effect. The atmosphere is relatively transparent to solar radiation, this means it allows sunlight to enter the atmosphere and heat the Earth's surface. These surfaces then re-radiate that heat as long-wave infra-red radiation, which greenhouse gases tend to absorb rather than transmit. The result is that the long-wave infra-red radiation is 'trapped' and heat accumulates in the atmosphere causing a warming process. See greenhouse gases for more information.
The thermal optical properties of a material are a function of three basic parameters; transmittance, reflectance, and absorptance (or emissivity) , describing the ratio of the transmitted, radiated or absorbed radiation to the incident radiation. These properties vary depending on the wavelength and angle of the incident radiation. See Thermal optical properties for more information.
Phase change - When substances change phase, for example changing from liquid to gas, they absorb or release heat energy. For example, when water evaporates, it absorbs heat, producing a cooling effect, and when it condenses it releases heat. So when water evaporates from the surface of a building, or when sweat evaporates from the skin, it has a cooling effect.
When substances change phase, for example changing from liquid to gas, they absorb or release heat energy. For example, when water evaporates, it absorbs heat, producing a cooling effect, and when it condenses it releases heat. So when water evaporates from the surface of a building, or when sweat evaporates from the skin, it has a cooling effect.
This is also important in refrigeration, where refrigerant gases absorb heat from the cooling medium (typically water) as they evaporate, and when they condense, they release heat which is rejected to the outside (or recovered). See Refrigerants for more information.
Phase change materials can also be used in construction to reduce internal temperature changes by storing latent heat in the solid-liquid or liquid-gas phase change of a material. See Phase change materials for more information.
Main author - Gregor Harvie
Gregor Harvie - Architect
Architect - Website
Website - Computational fluid dynamics for buildings
Computational fluid dynamics for buildings - CFD.jpg
CFD.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 How it works
2 How it works - 3 Limitations
3 Limitations - 4 Conclusion
4 Conclusion - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - 6 External references
6 External references - Introduction
Introduction - Computational fluid dynamics (CFD) is a technique used to model the behaviour of fluids.
Computational fluid dynamics (CFD) is a technique used to model the behaviour of fluids.
In building design it is typically used to model the movement and temperature of air within spaces. This is important as it allows designers to investigate internal conditions before a building is built, allowing them to test options and select the most effective solutions.
CFD can be used for modelling: -
The thermal comfort of occupants. - The distribution of environmental conditions within a space.
The distribution of environmental conditions within a space.
The effectiveness of building services (such as the positioning of air inlets and extracts or radiators).
The consequences of fire (such as the spread of heat and smoke).
The effectiveness of natural ventilation (such as the stack effect).
The build up of heat in specialist spaces such as server rooms.
The positioning of sensors. For example in a tall space, the temperature at the top might be very different to the temperature at the bottom. This can be important when positioning temperature sensors that feed back to the building management system. Otherwise, heating and cooling might be operating unnecessarily.
CFD can also be used to investigate the impact of a new building on air movement around a site, and has been used to model other 'fluid' behaviour, such as the movement of people.
Simulations are typically run for a number of different scenarios, testing behaviour under different levels of occupancy, different climatic conditions, in different modes of building services operation, with different openings between spaces and so on. This can build up an overall picture of how a building is likely to behave under normal operating conditions as well as during unusual or extreme conditions.
How it works - CFD works by dividing a space into a grid containing a large number of 'cells'. The grid of cells is surrounded by boundaries that simulate the surfaces and openings that enclose the space. The temperature of the boundaries, the air movement at openings, and the air temperature within the cells is then set to a starting condition which it is hoped is close to those that might be expected to be found within the space. These conditions might be determined using a boundary model that predicts boundary conditions, based on climatic and materials data. The more accurate the boundary model, and the closer the starting condition is to the final position predicted by the model, the faster the model will run and the more accurate the output is likely to be.
CFD works by dividing a space into a grid containing a large number of 'cells'. The grid of cells is surrounded by boundaries that simulate the surfaces and openings that enclose the space. The temperature of the boundaries, the air movement at openings, and the air temperature within the cells is then set to a starting condition which it is hoped is close to those that might be expected to be found within the space. These conditions might be determined using a boundary model that predicts boundary conditions, based on climatic and materials data. The more accurate the boundary model, and the closer the starting condition is to the final position predicted by the model, the faster the model will run and the more accurate the output is likely to be.
The software will then simulate the flow of air from each cell to those surrounding it, and the exchange of heat between the boundary surfaces and the cells adjacent to them. After a series of iterations, the model will come to a steady state that represents the actual air velocities and distribution of temperatures expected to be found within the space.
Increasingly, CFD software is able to interact with other models, such as:
Boundary models. - Climatic models.
Climatic models. - Building services models.
Building services models. - Energy consumption and CO2 generation models.
Energy consumption and CO2 generation models. - Radiant models.
Radiant models. - Daylighting and lighting models.
Daylighting and lighting models. - CAD and BIM software.
CAD and BIM software. - Limitations
Limitations - CFD can be a very useful tool in the right hands, and the output graphics are very persuasive and seductive. However results are highly dependent on the knowledge of the person setting up the model and interpreting the results. This is an increasing concern as CFD software becomes more straight-forward to use and so is more easily operated by people with little understanding of the mathematical model that underpins it.
CFD can be a very useful tool in the right hands, and the output graphics are very persuasive and seductive. However results are highly dependent on the knowledge of the person setting up the model and interpreting the results. This is an increasing concern as CFD software becomes more straight-forward to use and so is more easily operated by people with little understanding of the mathematical model that underpins it.
If the input information is wrong, the output information will be as well. CFD is no substitute for common sense.
An important consideration in developing a CFD model is the generation of the grid of cells. The greater the number of cells, the more accurate the simulation will be, but the longer the model will take to run. In some parts of a space, using a large cell size may not have a significant impact on the results, however in sensitive areas, for example around complex boundaries or where there might be a large temperature difference between a boundary surface and the air next to it, it is important that cells are as small as is computationally practical. For example a very small cell size (a fine grid mesh) is necessary to properly simulate the downdraft that can be experienced next to a cold window. If such a downdraft is not simulated, the heat exchange between the window and the space it encloses will be underestimated.
In spaces where the surfaces enclosing the space are non-cartesian (ie they are curved, or at an angle rather than purely horizontal or vertical) it is important that the grid is body-fitted (ie that it follows the contours of the surfaces) rather than cartesian (in a series of steps), otherwise air velocity at the surface will be underestimated and so heat transfer between the space and its enclosing surfaces will be underestimated. This is particularly important where there is a large temperature difference between the surface and the air adjacent to it.
Where CFD is being used to predict user comfort within a space, it is important that both air temperature and radiant temperature are considered. CFD in itself only models air temperature and air velocity, however, around half of the contribution to our thermal comfort within buildings is dependent on radiant heat transfer, ie the temperature of the surfaces around us. Some CFD software is able to include radiant influences on the temperatures that will be felt by occupants.
Conclusion - In the right hands, CFD can make a useful contribution to understanding the likely performance of a building. However, using CFD properly is time consuming and can be expensive, and in many circumstances there may be other, more straight-forward analytical techniques that will be more appropriate.
In the right hands, CFD can make a useful contribution to understanding the likely performance of a building. However, using CFD properly is time consuming and can be expensive, and in many circumstances there may be other, more straight-forward analytical techniques that will be more appropriate.
In cases where there are unique or complex circumstances, and an understanding of fluid behaviour is critical to the success of the building, CFD can be the only option available.
The word building' is commonly considered to refer to an enclosure within which activities can be carried out. It is a structure, usually consisting of a roof, walls, floors and openings such as doors and windows that is generally (but not always) positioned permanently in one location.
The Building Regulations suggest that the word 'building' refers to: ...any permanent or temporary building but not any other kind of structure or erection. That is, a tunnel, or bridge for example would not be considered to be a building.
The origins of buildings can be traced back over 44,000 years to the ice age and the Siberian Steppe, where remains have been found of simple shelters constructed from animal skins draped between sticks.
These tented structures thrived in regions where materials were scarce, or where survival required mobility; both conditions which tended to be brought about by low rainfall. Changing climates brought about a slow transition from nomadic tents to permanent huts and vice versa, and it was from the resultant process of intermediate modification that an enormous range of composite buildings evolved.
Some of these basic generic forms of structure are still used in remarkably un-changed forms throughout the world today, for example; the black tent, the mud brick hut and the yurt (a composite structure still in common use in Mongolia).
As well as being a noun, the word building is also used as a verb describing the act of constructing or making the thing itself. For more information see: Building work.
Buildings serve a diverse range of societal needs, but fundamentally they create shelter, providing a physical division between the inside and outside environments to provide:
Protection from wind, rain, solar radiation, snow and so on.
Regulation of the indoor environment in terms of temperature, humidity, moisture and so on.
Privacy for occupants. - A barrier to the transmission of noise.
A barrier to the transmission of noise. - Security for occupants and the building contents.
Security for occupants and the building contents. - Safety, for example preventing the spread of fire or smoke.
Safety, for example preventing the spread of fire or smoke.
This differs from the more general term structure which within the context of the built environment refers to anything that is constructed or built from interrelated parts with a fixed location on the ground. This includes buildings, but can also refer to any body that is designed to bear loads, such as a communications mast.
There are a very wide variety of buildings that have been constructed and used throughout history, in all manner of shapes, sizes and functions, and using all kinds of different materials. For more information, see Types of building.
Structure definition - Within the context of the built environment , the term structure refers to anything that is constructed or built from different interrelated parts with a fixed location on the ground.
Within the context of the built environment , the term structure refers to anything that is constructed or built from different interrelated parts with a fixed location on the ground.
This includes buildings, but the term structure can also be used to refer to any body of connected parts that is designed to bear loads, even if it is not intended to be occupied by people. Engineers sometimes refer to these as 'non-building' structures. Common examples include:
Aqueducts and viaducts. - Bridges.
Bridges. - Canals.
Canals. - Cooling towers and chimneys.
Cooling towers and chimneys. - Dams.
Dams. - Railways.
Railways. - Roads.
Roads. - Retaining walls.
Retaining walls. - Tunnels.
Tunnels. - Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineers work on a very wide range of structures, including; buildings, bridges, oil rigs, and so on.
Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineers work on a very wide range of structures, including; buildings, bridges, oil rigs, and so on.
Civil engineers design, construct, maintain and improve the physical environment, including bridges, tunnels, roads, railways, canals, dams, coastal defences, and so on. The term civil engineer is a more broad one than structural engineer that can include infrastructure such as pipelines, transportation, environmental engineering, maritime engineering, and so on. It was originally coined to distinguish it from military engineering.
Structural engineering was initially considered a sub-discipline of civil engineering, however it has developed into an important and complex specialism and is now be considered an specific engineering discipline in its own right.
According to William R Spillers 'Introduction to Structures', structural analysis is for the most part concerned with finding the structural response (the lateral deflection of a building under wind load, the reaction of a bridge to a moving train,) given external loads. In all but the most trivial cases, real structures, that is structures without the simplifications commonly associated with analysis, turn out to be impossibly complex. And what is finally analysed the structural model may appear at first glance to be quite different than the real structure.
In their most simple form, structural elements can be classified as:
One-dimensional: Ropes, struts, beams, arches.
Two-dimensional: Membranes, plates, slab, shells, vaults.
Three-dimensional: Solid masses. - Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, paragraph B3.iii defines elements of structure as:
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, paragraph B3.iii defines elements of structure as:
.the main structural loadbearing elements, such as structural frames, floors and loadbearing walls. Compartment walls are treated as elements of structure although they are not necessarily loadbearing. Roofs, unless they serve the function of a floor, are not treated as elements of structure. External walls, such as curtain walls or other forms of cladding which transmit only self weight and wind loads and do not transmit floor load, are not regarded as loadbearing
Very broadly, the 'substructure' refers to work below the underside of the screed or, where no screed exists, to the underside of the lowest floor finishes, and the 'superstructure includes works above that level. See Substructure and Superstructure for more detailed definitions.
NB The CDM Regulations suggest that structure means:
(a) any building, timber, masonry, metal or reinforced concrete structure, railway line or siding, tramway line, dock, harbour, inland navigation, tunnel, shaft, bridge, viaduct, waterworks, reservoir, pipe or pipeline, cable, aqueduct, sewer, sewage works, gasholder, road, airfield, sea defence works, river works, drainage works, earthworks, lagoon, dam, wall, caisson, mast, tower, pylon, underground tank, earth retaining structure or structure designed to preserve or alter any natural feature and fixed plant;
(b) any structure similar to anything specified in paragraph (a);
(c) any formwork, falsework, scaffold or other structure designed or used to provide support or means of access during construction work,
and any reference to a structure includes part of a structure.
RICS property measurement, 2nd edition, published by the Royal Institution of Chartered Surveyors (RICS) in January 2018, defines a structure as: A construction that provides shelter or serves an ancillary function, but is not necessarily fully enclosed.
Roof structure is a term that refers to the construction at the top of a building which typically provides protection from the elements. It generally comprises a system of structural members designed to support the roof build-up i.e the materials that provide watertightness and thermal and acoustic insulation to the building below.
The term roof structure tends to be associated with pitched or Mansard roofs, and special types of roof such as those made of space frames, trusses, barrel vaults and other structural forms. This sort of roof structure (apart from space frames) will often create a roof space that can be used for various functions, including for living accommodation, storage, office space, plant and other uses. Roof spaces so formed are frequently called lofts or attics.
A roof structure (sometimes simply called the roof) will often fulfil the functions of:
Weather resistance. - Strength and stability.
Strength and stability. - Fire resistance.
Fire resistance. - Thermal insulation.
Thermal insulation. - Acoustic insulation.
Acoustic insulation. - Security.
Security. - Privacy.
Privacy. - From a construction point of view, a traditional roof structure can be conceived of as a separate entity to the structure below it. For example, in a house of masonry construction, the roof structure is often a bolt-on framework comprising timber purlins and rafters fixed to wall plates which in turn are tied down to the masonry walls. This timber framework not only supports the roof build-up (insulation, coverings etc) but also creates a roof space that can be used for habitation. The roof structure also forms an aesthetic element in its own right.
From a construction point of view, a traditional roof structure can be conceived of as a separate entity to the structure below it. For example, in a house of masonry construction, the roof structure is often a bolt-on framework comprising timber purlins and rafters fixed to wall plates which in turn are tied down to the masonry walls. This timber framework not only supports the roof build-up (insulation, coverings etc) but also creates a roof space that can be used for habitation. The roof structure also forms an aesthetic element in its own right.
In normal framed applications, the system of steel or concrete beams is terminated on the underside of the roof build up. There is no separate roof structure as such, only the framing of the top floor beams and columns (supporting the roof build-up) which is considered part of the buildings superstructure. If, however, a Mansard or pitched roof is added, a system of steel (or timber) members will be used to create the roof structure and with it a new roof space that may have various uses.
Framed buildings may have a variety of construction systems added to the top. In these cases, the roof structure may be formed of a series of trusses, a space frame, barrel vaults, braced domes, folded slabs, north lights and tension structures, to name a few. However, most commercial multi-storey buildings have a roof slab that simply supports the roof build-up which provides protection from the weather.
The roof structure may also support walkways and other access equipment, building services plant, planting, water features, lighting, water storage and so on.
Buildings such as concert halls in noisy localities may require special consideration to be given to the design of the roof, with weight and discontinuity of structure necessary to achieve the suitable acoustics. This can make the roof structure design complex and expensive.
Likewise, resistance to the spread of fire will depend on proximity to other buildings, the nature of the building in question and the roof structure itself. Fire protection must prevent the passage of fire from adjacent roofs, while the roof structure must prevent fire spread from its roof space into other parts of the building. Considerations such as these can make the design of roof structures very complicated.
For more information see: Types of roof.
A braced frame is a structural system commonly used in structures subject to lateral loads such as wind and seismic pressure. The members in a braced frame are generally made of structural steel, which can work effectively both in tension and compression.
The beams and columns that form the frame carry vertical loads, and the bracing system carries the lateral loads. The positioning of braces, however, can be problematic as they can interfere with the design of the faade and the position of openings. Buildings adopting high-tech or post-modernist styles have responded to this by expressing bracing as an internal or external design feature.
Bracing systems - The resistance to horizontal forces is provided by two bracing systems:
The resistance to horizontal forces is provided by two bracing systems:
Vertical bracing - Bracing between column lines (in vertical planes) provides load paths for the transference of horizontal forces to ground level. Framed buildings require at least three planes of vertical bracing to brace both directions in plan and to resist torsion about a vertical axis.
Bracing between column lines (in vertical planes) provides load paths for the transference of horizontal forces to ground level. Framed buildings require at least three planes of vertical bracing to brace both directions in plan and to resist torsion about a vertical axis.
Horizontal bracing - The bracing at each floor (in horizontal planes) provides load paths for the transference of horizontal forces to the planes of vertical bracing. Horizontal bracing is needed at each floor level, however, the floor system itself may provide sufficient resistance. Roofs may require bracing.
The bracing at each floor (in horizontal planes) provides load paths for the transference of horizontal forces to the planes of vertical bracing. Horizontal bracing is needed at each floor level, however, the floor system itself may provide sufficient resistance. Roofs may require bracing.
Types of bracing - Single diagonals
Single diagonals - Singlediagonalbrace.jpg
Singlediagonalbrace.jpg -
Trussing, or triangulation, is formed by inserting diagonal structural members into rectangular areas of a structural frame, helping to stabilise the frame. If a single brace is used, it must be sufficiently resistant to tension and compression.
Cross-bracing - Xbrace.JPG
Xbrace.JPG -
Cross-bracing (or X-bracing) uses two diagonal members crossing each other. These only need to be resistant to tension, one brace at a time acting to resist sideways forces, depending on the direction of loading. As a result, steel cables can also be used for cross-bracing.
However, cross bracing on the outside face of a building can interfere with the positioning and functioning of window openings. It also results in greater bending in floor beams.
K-bracing - Kbrace.jpg
Kbrace.jpg -
K-braces connect to the columns at mid-height. This frame has more flexibility for the provision of openings in the facade and results in the least bending in floor beams. K-bracing is generally discouraged in seismic regions because of the potential for column failure if the compression brace buckles.
V-bracing - V-brace.jpg V-brace(inverted).jpg
V-brace.jpg V-brace(inverted).jpg -
Two diagonal members forming a V-shape extend downwards from the top two corners of a horizontal member and meet at a centre point on the lower horizontal member (left-hand diagram). Inverted V-bracing (right-hand diagram, also known as chevron bracing) involves the two members meeting at a centre point on the upper horizontal member.
Both systems can significantly reduce the buckling capacity of the compression brace so that it is less than the tension yield capacity of the tension brace. This can mean that when the braces reach their resistance capacity, the load must instead be resisted in the bending of the horizontal member.
Centric bracing is commonly used in seismic regions. It is similar to V-bracing but bracing members do not meet at a centre point. This means there is a space between them at the top connection (see photo above, Salesforce Tower, London). Bracing members connect to separate points on the horizontal beams. This is so the 'link' between the bracing members absorbs energy from seismic activity through plastic deformation. Eccentric single diagonals can also be used to brace a frame.
A girder is a large and deep type of beam that is used in construction. It is typically capable of longer spans and taking greater loads than a normal beam, and is often used as a main horizontal structural support for smaller beams, such as in bridge construction.
There are several different types of girder available depending on circumstances, and the load they are required to support:
Smaller steel girders can be 'rolled' into the required shape. When girders become larger however, a standard rolled shape may not be available and a plate girder may have to be fabricated instead.
A plate girder is typically an I-beam cross-section made up of separate structural steel plates which are welded, bolted or riveted together to form the deeper vertical web and narrower horizontal flanges of the beam. Plate girders are commonly-used for spans of up to 15m.
A gantry girder is used for a gantry crane - typically consisting of two A frames connected by a lattice cross member which straddles the work area. The lifting gear is suspended from the horizontal girder and can move along it on rails. For more information, see Types of crane.
A box girder is fabricated from steel plates used to form a rectangular box. This resists torsion better than a plate girder and can be used when depth constraints mean a plate girder cannot be made deeper.
Situated in Harrow on the Hill, the Kings Head Hotel Gantry is a commemorative sign that hangs from a horizontal beam. Despite being a modern reproduction, it is one of only a few remaining gantry signs in the UK and has been preserved for its significance.
Introduction - The term gantry has several different definitions in relation to construction. In the most general sense, a gantry is a structure that crosses over an area and can be used to display, support or suspend objects.
The term gantry has several different definitions in relation to construction. In the most general sense, a gantry is a structure that crosses over an area and can be used to display, support or suspend objects.
Types of gantries - A gantry can be small (as in a kitchen gantry, which can be used as a support system for pots and pans or decorative objects), medium (as in a decorative gantry such as the Kings Head Hotel Gantry Harrow) or large (as in the case of gantries that display road signs, railway signalling or speed camera equipment or other traffic control devices).
A gantry can be small (as in a kitchen gantry, which can be used as a support system for pots and pans or decorative objects), medium (as in a decorative gantry such as the Kings Head Hotel Gantry Harrow) or large (as in the case of gantries that display road signs, railway signalling or speed camera equipment or other traffic control devices).
Very large gantry scaffolds can be used to create bridge-like platforms that support towers, such as those used for electric power lines.
Gantry cranes (also known as portal cranes) typically consist of two A frames connected by a lattice cross member which straddles the work area. The lifting gear is suspended from the horizontal cross member and can move along it on rails. On small gantry cranes, the A frame may be wheel mounted, whereas larger cranes are typically mounted on powered bogies that run on rail tracks. Larger cranes tend to have the lifting gear mounted with a driving cab on the cross member.
Gantries may also be used for supporting window cleaning cradles and other facade access equipment.
Introduction - Hoists are used on construction sites to vertically transport materials and/or passengers. They are most commonly powered by diesel engines or electric motors that rotate a drum around which a wire rope is wound. Hoists may also be hydraulically powered, and may use chains as the lifting mechanism rather than wire rope.
Hoists are used on construction sites to vertically transport materials and/or passengers. They are most commonly powered by diesel engines or electric motors that rotate a drum around which a wire rope is wound. Hoists may also be hydraulically powered, and may use chains as the lifting mechanism rather than wire rope.
The landing area must be fitted with some form of guard, usually sliding gates, and the base of the hoist, where the winch is situated, should be well guarded to prevent injury. There must be a risk assessment undertaken prior to hoisting, and subsequent lifting operations should be properly planned and carried out in accordance with the Lifting Operations and Lifting Equipment Regulations 1998 (LOLER).
Hoists differ from cranes in that cranes move items vertically and horizontally. Hoists differ from lifts in that they are generally used for industrial purposes and are not publicly accessible. Winches are typically used to pull or drag items along level surfaces, rather than lifting them vertically.
Mobile hoists - Mobile hoists are commonly found on construction sites, and are capable of lifting material loads to heights of up to 30 m. They are designed to be dismantled, folded onto the chassis and moved to another location with relative ease, either under their own power or towed by a haulage vehicle.
Mobile hoists are commonly found on construction sites, and are capable of lifting material loads to heights of up to 30 m. They are designed to be dismantled, folded onto the chassis and moved to another location with relative ease, either under their own power or towed by a haulage vehicle.
The mast and winch unit is mounted on a platform, typically with a load capacity of 500 kg. This is then stabilised using jacks or outriggers. Extending upwards, a lattice hoist mast is constructed to which sections can be added depending on the height required, together with tie supports fixed to scaffolding or the building frame. A protective screen is placed around the hoist mast, fitted with gates at least 2 m high at all landing levels.
Passenger hoists - These are designed to lift passengers, although they can also be used for materials as long as the weight is kept within the loading capacity. The type of hoist can vary from a single cage with rope suspension to twin cages with rack and pinion operation mounted on two sides of a static tower. They are usually controlled from within the cage, and there must be additional safety devices to prevent over-run or free-fall.
These are designed to lift passengers, although they can also be used for materials as long as the weight is kept within the loading capacity. The type of hoist can vary from a single cage with rope suspension to twin cages with rack and pinion operation mounted on two sides of a static tower. They are usually controlled from within the cage, and there must be additional safety devices to prevent over-run or free-fall.
A typical passenger hoist cage is 2.7 m high and capable of carrying 12 passengers at a total weight of 1,000 kg. Typical speeds are 40-100 m/min. The hoist tower is generally assembled from 1.5 m-long sections and tied at 12 m centres to the face of the structure.
Small package hoists - Small hoists consisting of a small lifting arm, simple electric motor and wire rope can be bolted to a structure or to scaffolding and used for light-lifting operations of around 500kg.
Small hoists consisting of a small lifting arm, simple electric motor and wire rope can be bolted to a structure or to scaffolding and used for light-lifting operations of around 500kg.
A tremie is a pipe that can be used for pouring concrete below ground level, often underwater. Common applications include piling works, basements, diaphragm walls, caissons, underwater foundations, and so on.
A tremie is made of rigid metal or plastic tubes, generally with a diameter ranging from 20 - 30 cm. At the head of the tremie pipe is a feed hopper into which concrete is placed. The use of a tremie helps avoid cement washing out of the mix while flowing, and so produces a more reliable strength concrete. Concrete intended for tremie placement should have a very high slump of approximately 150 - 200 mm.
The process begins by lowering a tremie pipe to the point where the concrete is going to be placed. It is important to keep air and water out of the tremie during this placement which is achieved by keeping it full of concrete. A pig, or foam rubber plug, can be used which is forced down the inside of the tremie by the concrete, displacing the water as it does so. The pig is pushed out of the bottom of the tremie and floats to the surface.
The lower end of the tremie should be buried in the mass of concrete as it flows out, as this limits the washing out of cement from the fresh concrete and prevents aggregate segregation. The concrete should be poured into the hopper continuously at a sufficient rate to avoid it setting in the tremie and, if necessary, admixtures can be used to alter the curing time, workability, slump, and so on.
The end of the tremie should be immersed by approximately 3 feet, and as the mix flows out towards the edges and builds up this will generally raise the tremie automatically, although it should be raised manually if necessary. Care should be taken not to raise the tremie to the extent that it breaks out of the freshly poured concrete as this would expose the bottom end to water.
However, if the tremie needs to be moved laterally it is recommended that it is lifted out vertically, plugged, and a new pour started at the new position as opposed to dragging the tremie through the concrete.
Several tremies should be used simultaneously if the pour area is too large for just one to be used and moved around. Tremies should be spaced 3.5 - 5 m apart and around 2.5 m from the formwork. By providing a continuous concrete flow through the tremies, a moderately even surface can be maintained and the risk of uneven setting can be minimised.
An admixture is a substance which can be added to concrete to achieve or modify its properties. Admixtures are added to the concrete, in addition to cement, water and aggregate, typically immediately before or during the mixing process.
Admixtures can be used to reduce the cost of building with concrete, or to ensure certain required properties or quality of the cured concrete. If problems arise with the concrete during the construction process, admixtures can be used as an emergency measure to try and prevent failure. In addition, some of the main functions of using admixtures include:
Water-reducing: Can reduce the water content needed to reach a required slump by 5-10%.
Retarding: Slow the setting rate of concrete, keeping it workable and are often used to counteract the accelerating effect of hot weather.
Accelerating: Increase the rate of early-strength development and reduce the time required for curing.
Superplasticizers: Can reduce water content by 12-30% to make a highly fluid but workable form of concrete known as flowing concrete.
Corrosion-inhibiting: Used to slow the corrosion of reinforcing steel in the concrete. Often used in marine structures, bridges and others that will be exposed to chloride in high quantities.
Air-entraining: Small bubbles of air formed uniformly through the concrete mix to increase cohesion and resistance to freeze-thaw degradation.
Improving the curing of the concrete. - Providing waterproofing properties.
Providing waterproofing properties. - To improve hardness.
To improve hardness. - Providing colour.
Providing colour. - Offsetting or reducing a chemical reaction.
Offsetting or reducing a chemical reaction. - Aeration to reduce the weight.
Aeration to reduce the weight. - Offsetting or reducing shrinkage.
Offsetting or reducing shrinkage. - Dispersing cement particles when mixed with water.
Dispersing cement particles when mixed with water. - Alkali-silica reactivity reduction.
Alkali-silica reactivity reduction. - Admixtures are usually provided in a liquid form. Some admixtures, such as pigments, pumping aids and expansive agents, are typically added manually from pre-measured containers as the amount used is very small.
Admixtures are usually provided in a liquid form. Some admixtures, such as pigments, pumping aids and expansive agents, are typically added manually from pre-measured containers as the amount used is very small.
In the construction industry, fillers are generally either:
Materials that are added to other materials to modify them, making them cheaper, lighter and so on.
Materials that create separation between other materials. - Materials that are used to fill gaps in constructions, such as cracks, holes and joints.
Materials that are used to fill gaps in constructions, such as cracks, holes and joints.
Fillers for gaps have a wide range of densities, drying times, waterproofing, breathability, adhesive qualities, flexibility, colour, coarseness and so on depending on the required use.
For example, mortar can be considered a filler, as it effectively fills the gaps between bricks or stones. For more information see: Mortar.
Grout is fluid, viscous material that is used to fill and seal gaps. It is similar to mortar, but the water concentration is greater and it is less stiff which makes it more suitable for filling complex, inaccessible or small spaces. It is commonly used for tiling. For more information see: Grout.
Caulk is a commonly used filler used by decorators. It is a flexible filler typically made from acrylics or silicone, that dries quickly, but remains flexible, and so it is suitable for use where movement may be expected (such as between a plaster wall and a timber skirting). Historically caulk was made from fibrous materials that could be driven between boards, pipes and so on to make them waterproof, and rope caulks are still available. For more information see: Caulk
Silicone is a man-made polymer that is derived from silicon. It is a class of silicon-based chemical compounds that can be used to form flexible, adhesive, waterproof joints, for example around baths and showers. For more information see: Silicone.
Putty is made typically by mixing a finely ground chalk (whiting) with linseed oil. It is commonly used in traditional glazing to seal panes of glass into timber frames. Synthetic putty can be made using polybutene. For more information see: Putty.
Dry fillers are available in a powdered form, and typically consist of a powdered aggregate and an adhesive, to which water is added to the required consistency. They can generally be sanded when dry to a smooth finish and can then be painted with conventional paints.
Ready mix fillers are essentially dry fillers that have been pre-mixed so they are ready to use. They come in different degrees of stiffness, coarseness adhesion and flexibility depending on the use for which they are required. They also come in multi-purpose forms which are suitable for most common applications.
Highly-adhesive fillers are available which not only fill gaps, but also bond the items on either side of the gap, combining the properties of a filler and a glue. These are now commonly used as a substitute for nails.
Expanding foams are available for large, complex or difficult to reach gaps. They expand significantly on being discharged from a can to fill almost any size or shape or hole.
Introduction - Grout is fluid, viscous material that is used to fill and seal gaps. It is similar to mortar, but the water concentration is greater and it is less stiff which makes it more suitable for filling complex, inaccessible or small spaces.
Grout is fluid, viscous material that is used to fill and seal gaps. It is similar to mortar, but the water concentration is greater and it is less stiff which makes it more suitable for filling complex, inaccessible or small spaces.
It is commonly used for tiling, but is also used in structural and civil engineering applications.
Tiling grout - Types
Types - Tiling grout is used to fill spaces between tiles, helping secure the tile to its base and acting as a sealant, preventing moisture from penetrating joints:
Tiling grout is used to fill spaces between tiles, helping secure the tile to its base and acting as a sealant, preventing moisture from penetrating joints:
Smaller tile joints tend to use non-sanded grout, which is cement-based and designed for use on tile surfaces that are dry when the grout is applied.
Larger joints tend to use sanded grout, which is a cement-based mortar with small sand grains added to assist setting and provide a stronger grout. It should be tested first to make sure the sand will not scratch the tile surface.
Epoxy grout has water-resistant properties and does not require additional sealing. It also prevents bacteria growth and limits cracking. This type of grout is ideal where tiles may be exposed to large amounts of water, chemicals or grease. It can be produced in sanded and unsanded varieties.
Furan grout is similar to epoxy but is composed of polymers of fortified alcohols which give it highly chemical-resistance properties. It is typically used for brick pavers and quarry tiles, and is particularly suited to areas that are exposed to chemicals and grease.
Application - The first step, if re-grouting a surface, is to remove the old grout using a grout saw or scraper.
The first step, if re-grouting a surface, is to remove the old grout using a grout saw or scraper.
The colour of grout should be carefully selected as this will determine how the eye perceives the tiles. Light grout tends to become invisible and accentuates the individual tiles whereas dark grout tends to accentuate the tile pattern. However, lighter colours are more likely to noticeably discolour.
The thinset mortar, which is used to fix the tiles during installation, must have cured before grouting can proceed. Grouting should be mixed according to the directions. A float should be used to spread the grout over joints, moving it at a diagonal angle to the grout lines for a smooth finish.
Some 15-30 minutes after applying the grout, use a large sponge with water to remove excess grout from the tile surfaces. This should be repeated again after a few hours until the grout lines are smooth.
Refer to the manufacturers directions in terms of how long to wait for the grout to cure before sealing it. Make sure the room has good ventilation. Pour a small amount of sealant on the grout and, with small circular motions, work it in using a sponge. After 5-10 minutes this can be wiped off. It is generally recommended that the grout is regularly re-sealed.
Tools - Some of the tools that are commonly used for groutwork include:
Some of the tools that are commonly used for groutwork include:
Grout saw or scraper: A manual tool used to remove old and discoloured grout from joints.
Grout float: A trowel-like tool made of rubber, used for smoothing the grout line surface.
Grout sealer: Water or solvent-based sealant applied over dried grout.
Pointing trowel: Used for applying grout in stone works such as flagstones.
Structural grout - Structural grout cab be used to fill voids in masonry that contains reinforcement steel, helping to secure the steel in pace and bond it to the masonry. It is a particularly strong grout that can withstand vibration and dynamic load shock, and tends not to shrink.
Structural grout cab be used to fill voids in masonry that contains reinforcement steel, helping to secure the steel in pace and bond it to the masonry. It is a particularly strong grout that can withstand vibration and dynamic load shock, and tends not to shrink.
Non-shrink grout - Non-shrink grout is a hydraulic cement grout that hardens at a volume that is greater or equal to its original volume. It sets rapidly and includes ingredients to compensate against cement stone shrinkage. It is often used between load-bearing members as a transfer medium.
Non-shrink grout is a hydraulic cement grout that hardens at a volume that is greater or equal to its original volume. It sets rapidly and includes ingredients to compensate against cement stone shrinkage. It is often used between load-bearing members as a transfer medium.
Civil engineering - Grouting in civil engineering refers to the injection of pumpable materials into a soil or rock formation to alter its physical characteristics. Different materials may be used for grouting depending upon soil type, the size of fissures and so on, however, the basic process is the same: the soil or rock is injected with grout which sets and reduces or acts as a sealant on the materials permeability.
Grouting in civil engineering refers to the injection of pumpable materials into a soil or rock formation to alter its physical characteristics. Different materials may be used for grouting depending upon soil type, the size of fissures and so on, however, the basic process is the same: the soil or rock is injected with grout which sets and reduces or acts as a sealant on the materials permeability.
Types of grout used in civil engineering include:
Cement grouting. - Bentonite grouting.
Bentonite grouting. - Chemical grouting.
Chemical grouting. - Resin grouting.
Resin grouting. - Bituminous grouting.
Bituminous grouting. - For more information, see Grouting in civil engineering
For more information, see Grouting in civil engineering
Introduction - Ceramics are a material often used in construction, made from a mixture of minerals, typically silica sand, with a clay binder and some impurities, and up to 30% water. They are fired at a higher temperature than bricks, so that the silica re-crystallises to form a glassy material that has greater density, strength, hardness, resistance to chemicals and frost and a greater dimensional stability.
Ceramics are a material often used in construction, made from a mixture of minerals, typically silica sand, with a clay binder and some impurities, and up to 30% water. They are fired at a higher temperature than bricks, so that the silica re-crystallises to form a glassy material that has greater density, strength, hardness, resistance to chemicals and frost and a greater dimensional stability.
During firing, the water is driven off, though this may be reduced from 30% to 2-5% by drying before firing. At this reduced water content products are moulded as powder before being fired at 1,800-2,000 degrees for days or weeks at a time, depending on the ceramic and process details. Ceramics may have an as-fired appearance or be glazed (a glass-like coating).
These materials are environmentally stable - they will not oxidise further in the atmosphere, therefore, they are economical in terms of maintenance costs. Problems are likely to occur when they are combined with other materials, typically fixings which are highly stressed and subject to corrosion. If fixings fail, the result can be dramatic. Unlike metals, ceramics are not capable of ductile behaviour. They fail in a brittle manner, directly after their elastic limit.
Types of ceramics - Fire clays and shales
Fire clays and shales - These products include ordinary bricks, clay roof tiles, flooring quarries and pavers.
These products include ordinary bricks, clay roof tiles, flooring quarries and pavers.
Terracotta - This is literally burnt earth. It is made from yellow to brownish-red clays with a uniformity and fineness between brick and vitrified wall tiles. Terracotta is often used for unglazed chimney pots, air bricks, copings and planters.
This is literally burnt earth. It is made from yellow to brownish-red clays with a uniformity and fineness between brick and vitrified wall tiles. Terracotta is often used for unglazed chimney pots, air bricks, copings and planters.
For more information, see Terracotta. -
Faience - This is a glazed form of terra-cotta or stoneware. The base material may be fired to the biscuit stage before glazing and re-firing, or a once-fired process may be used. The latter improves resistance of the glaze to crazing (the spread of lines or cracks on the glazed surface), but reduces the range of colours available.
This is a glazed form of terra-cotta or stoneware. The base material may be fired to the biscuit stage before glazing and re-firing, or a once-fired process may be used. The latter improves resistance of the glaze to crazing (the spread of lines or cracks on the glazed surface), but reduces the range of colours available.
For more information see: Faience. -
Fireclay - This contains a high proportion of clay resistant to high temperatures (kaolin). It is used for chimney flue linings and firebacks.
This contains a high proportion of clay resistant to high temperatures (kaolin). It is used for chimney flue linings and firebacks.
Stoneware - This is similar in composition to fireclay, but is fired at a higher temperature than fireclay and contains a higher proportion of glass. As a result it is harder and less absorbent. Modern manufacturing processes mean that stoneware no longer has to be glazed for use in drainage pipes.
This is similar in composition to fireclay, but is fired at a higher temperature than fireclay and contains a higher proportion of glass. As a result it is harder and less absorbent. Modern manufacturing processes mean that stoneware no longer has to be glazed for use in drainage pipes.
Earthenware - The raw materials are blended and may contain a considerable proportion of limestone. It is a finer product than stoneware and is used as the body for glazed wall tiles and table china. Water absorption may be up to 15%, however, making it less suitable for sanitaryware than vitreous china.
The raw materials are blended and may contain a considerable proportion of limestone. It is a finer product than stoneware and is used as the body for glazed wall tiles and table china. Water absorption may be up to 15%, however, making it less suitable for sanitaryware than vitreous china.
Vitreous china - This has a higher glass content than earthenware, and its water absorption is only about 0.5%, which makes it suitable for sanitary fittings. It is stronger than earthenware.
This has a higher glass content than earthenware, and its water absorption is only about 0.5%, which makes it suitable for sanitary fittings. It is stronger than earthenware.
Porcelain - Porcelain is very similar to vitreous china, but is often made from purer materials under more strictly controlled conditions. It is used for special uses, such as electrical insulators.
Porcelain is very similar to vitreous china, but is often made from purer materials under more strictly controlled conditions. It is used for special uses, such as electrical insulators.
New ceramics - These are also called technical or engineering ceramics. Their purity is far higher than traditional ceramics, not using raw clay mined directly from the ground. Powders are formed which are then cast, pressed, extruded or moulded into shape. The powders may be set in organic binders. The combination of pure materials and exacting production techniques ensures the very high strength of these materials.
These are also called technical or engineering ceramics. Their purity is far higher than traditional ceramics, not using raw clay mined directly from the ground. Powders are formed which are then cast, pressed, extruded or moulded into shape. The powders may be set in organic binders. The combination of pure materials and exacting production techniques ensures the very high strength of these materials.
A brick veneer, also known as a brick slip, is a thin layer of brick that is used aesthetically as a form of surface finish rather than structurally. Conventional brick walls typically support the structural loads of the building, whereas brick veneers are applied for decorative purposes.
They are generally formed from thin brick slips, which may be as little as 20 mm thick (compared to 102.5 mm for a standard brick). Brick veneers can be used for both indoor and outdoor applications and can be applied to almost any surface. A range of special brick slips are available for conditions such as corners, to continue the illusion that walls are constructed from full bricks.
For interior applications, such as around fireplaces, brick veneers may laid in a similar way to tiles. Mortar (or some other adhesive) is spread on the wall and the bricks are set into place on it, separated during drying by plastic spacers. Once bed mortar has set, the brick joints are pointed using more mortar. Other 'veneers' are available in rolls, as a form of three-dimensional wallpaper.
For exterior applications, the veneer may be laid in a similar way to internal applications, as a form of cladding. However, they may also be installed as a free-standing panels (often prefabricated off site, and sometimes including other components such as insulation), anchored back to the structural frame. This type of veneer is vertically self-supporting, but in multi-storey buildings, shelf angles may be used to provide a horizontal expansion joint, usually at the floor edges. This allows for expansion of the brick and potential shrinkage of the frame.
There are several advantages to using brick veneers:
They are relatively easy and quick to install.
They are not as heavy as other forms of masonry, which reduces structural loading.
Cavities behind external brick veneers can aid insulation.
They are durable and fire-resistant. - They can achieve a wide range of decorative functions
They can achieve a wide range of decorative functions
They require little maintenance. - Disadvantages include:
Disadvantages include: -
They are more susceptible to damage as they are thinner than conventional brick walls.
They do not contribute to structural integrity. - They can be susceptible to water damage.
They can be susceptible to water damage. - Over time, the veneer will require re-pointing with new mortar.
Over time, the veneer will require re-pointing with new mortar.
Chert is a type of fine-grained and silica-rich sedimentary rock. It often contains microfossils and/or macrofossils, and can be found in a great variety of colours. It is often confused with flint which is a particular type of chert.
Chert occurs in geology as nodules, concretionary masses and layered deposits, and is characterised by its hardness and conchoidal fractures that create sharp edges. It was these properties that meant chert was used in early human civilisations for creating tools and weapons.
Chert is often used as an aggregate and as a material for road surfacing. It is particularly suited to road surfacing as rainwater firms and compacts it rather than making it 'muddy' like some other fill materials.
However, there can be problems when is used as an aggregate in concrete, such as the development of surface pop-outs as a result of freezing and thawing. This is due to the high porosity of weathered chert. In addition, some kinds of chert can undergo an alkali-silica reaction (ASR) when they come into contact with high-alkali cement which can lead to cracking or expansion.
Development, in terms of land, property or real estate, is a complex process of coordinating various activities to transform ideas and plans into physical reality. As a business process, it involves the financing, construction, renovation or refurbishment of buildings and land in order to make a profit.
The key phase in property development is deciding the nature of the development to be undertaken and whether or not to proceed with it. These decisions are based on an evaluation of the market, and financial appraisal of the proposed development, including the likely constraints, risks and profit.
The development process can be summarised as: -
Initiation and evaluation. - Land and property acquisition.
Land and property acquisition. - Design and permissions.
Design and permissions. - Construction.
Construction. - Management or disposal.
Management or disposal. - Development is a much wider process than construction, which is principally the building of something such as a house, tunnel, bridge, etc. However, developers often manage the construction process as part of the overall development.
Development is a much wider process than construction, which is principally the building of something such as a house, tunnel, bridge, etc. However, developers often manage the construction process as part of the overall development.
Development evaluation requires assessment of a great number of criteria; funding can be difficult to secure, purchases and sales can take considerable time, and developments can require a great deal of management.
Planning permission is the legal process of determining whether proposed developments should be permitted. Responsibility for planning lies with local planning authorities (usually the planning department of the district or borough council). Other than permitted developments, (which are considered to have insignificant impact), all developments require planning permission. This can be one of the most significant risks for developments.
The term 'speculative development' describes a process in which unused land is purchased or a building project is undertaken with no formal commitment from any end users. In other words, the end user of the development is unknown, but the developer is nonetheless confident not only that they will be able to find a one, but that the type of development they are undertaking will be suitable.
A 'committed development' is one that has received full or outline planning permission, or is allocated in an adopted development plan.
The National Planning Policy Framework (NPPF) Annex 2: Glossary, published by the Ministry of Housing, Communities & Local Government (MHCLG) in 2012, suggests that: To be considered developable, sites should be in a suitable location for housing development with a reasonable prospect that they will be available and could be viably developed at the point envisaged.
Buyer-funded development, also known as investor-led fractional sales, is a model of financing property development that typically involves using deposits from individual buyers to fund apartment buildings. Buyers of the apartments purchase off-plan, paying deposits of up to 80%.
This model of financing has become more common since the 2008 financial crisis as it has been harder for developers to fund schemes through traditional borrowing from banks or institutional lenders. It differs from more conventional models of off-plan development where buyers deposits (usually 10%) are held in secure escrow accounts and released only on project completion.
It has been subject to wide criticism as a risky form of investment, with the Solicitors Regulation Authority warning that buyers may be unwittingly financing high-risk or fraudulent property development. Since the large deposit is paid up-front, it can be spent on project costs and fees before any construction work actually begins, and when construction does begin it can be without the commitment of funding necessary to enable it to be completed. There is also no safety net if the developer becomes insolvent, funds run out, or if the developer fails to deliver the project as proposed.
The term apartment refers to a self-contained housing unit that occupies only part of a building, typically, on a single level. It is generally associated with North American real estate, although apartments have been common as far back as the Roman times. The term itself is thought to have originated in the mid-17th century, from the French word appartement derived from the Italian appartamento in turn derived from appartare', meaning to separate.
In North America, apartments are typically leased. Residential blocks in which the residents own their accommodation are generally referred to as condominiums.
The term apartment is sometimes considered to be synonymous with the term flat commonly used in the UK. However, Approved document B, Fire Safety, Volume 1 Dwelling houses, defines a flat specifically as; 'a separate and self-contained premises constructed or adapted for use for residential purposes and forming part of a building from some other part of which it is divided horizontally.' and suggests that this '...includes live/work units, i.e. a flat intended to serve as a workplace for its occupants and for persons who do not live on the premises.
For more information see: Flat definition. -
In the UK, the term duplex refers to an apartment (not a house) that includes two floors of accommodation, joined by an internal staircase. Historically, this would have been referred to as a maisonette, but the term duplex has become increasingly popular because of its perceived Americanism, and is generally applied to apartments with a more modern design, whereas a maisonette might be more traditional.
For more information see: Duplex. -
The term 'penthouse' is used to describe an apartment on the top floor of a high-rise building. According to the New York City building code, a penthouse is ...an enclosed structure on or above the roof of any part of a building, which is designed or used for human occupancy. Penthouses are frequently the largest, most luxurious, and therefore the most expensive, apartments in a building.
The term ground level, or ground floor, is used to refer to the level of a building that is at ground / street level. The term storey tends to refer to all levels of a building above the ground level.
It can also refer to the level of ground that has not be built on. The level of the ground before any excavation or filling has been carried out is referred to as the natural ground level, whereas finished ground level is when it has been finished with paving stones, asphalt, landscaped grass, and so on.
In construction terms, excavation is the process of removing earth to form a cavity in the ground.
On small sites or in confined spaces, excavation may be carried out by manual means using tools such as picks, shovels and wheelbarrows. Larger scale excavation works will require heavy plant such as bulldozers and backactors. For more information, see Excavating plant.
Material types - A common method of classification is by the material being excavated:
A common method of classification is by the material being excavated:
Topsoil excavation - This involves the removal of the exposed layer of the earths surface, including any vegetation or decaying matter which could make the soil compressible and therefore unsuitable for bearing structural loads. The depth will vary from site to site, but is usually in a range of 150-300 mm.
This involves the removal of the exposed layer of the earths surface, including any vegetation or decaying matter which could make the soil compressible and therefore unsuitable for bearing structural loads. The depth will vary from site to site, but is usually in a range of 150-300 mm.
Earth excavation - This involves the removal of the layer of soil directly beneath the topsoil. The removed material (referred to as 'spoil') is often stockpiled and used to construct embankments and foundations.
This involves the removal of the layer of soil directly beneath the topsoil. The removed material (referred to as 'spoil') is often stockpiled and used to construct embankments and foundations.
Rock excavation - This is the removal of material that cannot be excavated without using special excavation methods such as drilling (by hand or with heavy machinery) or blasting with explosives.
This is the removal of material that cannot be excavated without using special excavation methods such as drilling (by hand or with heavy machinery) or blasting with explosives.
Muck excavation - This is the removal of excessively wet material and soil that is unsuitable for stockpiling.
This is the removal of excessively wet material and soil that is unsuitable for stockpiling.
Unclassified excavation - This is the removal of a combination of the above materials, such as where it is difficult to distinguish between the materials encountered.
This is the removal of a combination of the above materials, such as where it is difficult to distinguish between the materials encountered.
Excavation purpose - Excavation can also be classified according to the purpose of the work:
Excavation can also be classified according to the purpose of the work:
Cut and fill excavation - This is the process of excavation whereby the material that is cut or stripped. The removed topsoil and earth can be used as fill for embankments, elevated sections, and so on. It can also be used to form a level surface on which to build, as elevated sections of the site are cut and moved to fill lower sections of the site.
This is the process of excavation whereby the material that is cut or stripped. The removed topsoil and earth can be used as fill for embankments, elevated sections, and so on. It can also be used to form a level surface on which to build, as elevated sections of the site are cut and moved to fill lower sections of the site.
Trench excavation - A trench is an excavation in which the length greatly exceeds the depth. Shallow trenches are usually considered to be less than 6 m deep, and deep trenches greater than 6 m.
A trench is an excavation in which the length greatly exceeds the depth. Shallow trenches are usually considered to be less than 6 m deep, and deep trenches greater than 6 m.
Trench, or footing, excavation is typically used to form strip foundations, buried services, and so on. The choice of technique and plant for excavating, supporting and backfilling the trench depends on factors such as; the purpose of the trench, the ground conditions, the trench location, the number of obstructions, and so on.
The common techniques that are used include: -
Full depth, full length: Suitable for long narrow trenches of shallow depth, such as pipelines and sewers.
Full depth, successive stages: Suitable for deep trenches where works can progress in sequence, reducing the risk of collapse.
Stage depth, successive stages: Suitable for very deep trenches in confined areas, deep foundations and underpinning.
Basement excavation - A basement is part of a building that is either partially or completely below ground level. For more information, see Basement excavation.
A basement is part of a building that is either partially or completely below ground level. For more information, see Basement excavation.
Road excavation - This typically involves stripping topsoil and cut-and-fill. For more information, see Road construction.
This typically involves stripping topsoil and cut-and-fill. For more information, see Road construction.
Bridge excavation - This typically involves the removal of material for the footing and abutments of bridges. The work may be subdivided into wet, dry and rock excavation. Underwater excavations may require special methods of drill and blast. For more information, see Bridge construction.
This typically involves the removal of material for the footing and abutments of bridges. The work may be subdivided into wet, dry and rock excavation. Underwater excavations may require special methods of drill and blast. For more information, see Bridge construction.
Dredging - Dredging is the process of excavating and removing sediments and debris from below water level, typically from the bottom of lakes, rivers, harbours, and so on. For more information, see Dredging.
Dredging is the process of excavating and removing sediments and debris from below water level, typically from the bottom of lakes, rivers, harbours, and so on. For more information, see Dredging.
Over excavation - Excavation that goes beyond the depth which is required for the formation of a below ground structure due to the presence of unsuitable material that must be removed.
Excavation that goes beyond the depth which is required for the formation of a below ground structure due to the presence of unsuitable material that must be removed.
For more information see: Over excavation. -
A roof is a structure forming the upper covering of a building or other shelter. Its primary purpose is generally to provide protection from the elements, but it may also contribute to safety, security, privacy, insulation, and so on.
Roofs may have openings or windows within them to allow light into the buildings, as well as providing, access, ventilation, views, and so on. They also frequently include other features such as chimneys, communications infrastructure, building services, drainage, lighting, access routes, and so on.
Roofs can be constructed from a wide variety of materials and in a wide variety of shapes depending on the requirements they have to satisfy, the local climate, the availability of materials and skills, the span to be covered, and so on.
This article provides links to further information about a range of roof types.
The term lighting refers to equipment, the primary purpose of which, is to produce light. This is typically some form of lamp, but lighting can also refer to the use of natural light to provide illumination.
Light is the electromagnetic radiation that exists within a certain portion of the electromagnetic spectrum. In terms of 'visible light', i.e. that which enables the sense of sight, it is the part of the spectrum that can be detected and seen by the eye.
The level of light on a surface is described as Illuminance and is measured in lux (lx), where one lux is equal to one lumen per square metre (lm/m) and a lumen is the SI unit (International System) of luminous flux, describing the quantity of light emitted by a lamp or received at a surface.
In relation to external lighting, Urban Design Guidelines for Victoria, published by The State of Victoria Department of Environment, Land, Water and Planning in 2017 suggests that: Lighting performs a number of functions, from supporting way-finding, orientation and safe movement at night to providing a decorative effect for building facades, landmarks and paths. Lighting systems can be large- scale and utilitarian, or small and ornamental. They may use overhead lamps, bollards, up-lights, bulkhead or veranda lighting, feature and facade illumination. Shop display lighting can also contribute to overall public realm lighting levels. Lighting is critical to creating a public realm that is safe and inviting for users.
Falsework is '...scaffolding or other temporary structures used to support construction components until the construction is sufficiently advanced to allow the structure to support itself'. Ref The HS2 London-West Midlands Environmental Statement, Department for Transport, November 2013.
There are three main types of systems used for falsework. These include:
Type 1 - Aluminium support legs with aluminium frames assembled into falsework systems, such as; Ischebeck Titan, SGB GASS or PERI MultiProp.
Type 2 - Individual aluminium or steel props, including either timber header beams or proprietary panels, such as ; PERI Multiflex or Doka Eurex Systems.
Type 3 - Heavier steel falsework, such as; RMD Kwikform System Shoring or A-Plant Acrow Props.
The design philosophy behind falsework differs from that of permanent works. They are highly stressed, usually to 90% of their capacity over short periods of time and involve reusable components. Props are rarely tied down and rely on their self-weight and supported load for lateral stability.
The design of the falsework must make allowances for erection tolerances and take into account that the components are re-used many times.
Falsework capacities are provided by the manufactures and permanent, imposed and environmental loads must all be taken account of in their design.
As with general construction, stability is often identified as the main cause of collapse. BS 5975 (BSI, 2011; clause [IP address hidden]) recommends that all falsework is designed for 2.5% of the vertical load acting horizontally as a tolerance for workmanship during erection.
Workmanship and inspections play key roles in the design and installation of falsework, as attention to detail is particularly important.
NB BS 5975: Code of practice for temporary works procedures and the permissible stress design of falsework, was revised in 2019. It provides guidelines for the design, specification, construction and removal of falsework.
Ant Burd, BSI head of built environment, said: This is a significant revision of an important standard that seeks to reflect changes in working practices and health & safety regulation within temporary construction and falsework. It offers procedural guidance to all organizations and personnel involved, to ensure competence in construction projects, from Principal Contractors and clients through to designers and trainers. The standard gives clear instructions and guidance to help companies be properly prepared for site investigations and compliant with current regulation.
Hoarding is a temporary structure of solid construction, erected around the perimeter of construction sites to shield them from view and prevent unauthorised access. It is an important component in ensuring health and safety, for site workers, visitors and the general public and can also be part of a site security system to prevent theft or vandalism.
Road construction - Road surfacing.jpg
Road surfacing.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Setting out
2 Setting out - 3 Earthworks
3 Earthworks - 3.1 Subgrade strength
3.1 Subgrade strength - 4 Paving construction
4 Paving construction - 4.1 Flexible paving
4.1 Flexible paving - 4.1.1 Surfacing
4.1.1 Surfacing - 4.1.2 Sub-base
4.1.2 Sub-base - 4.2 Rigid paving
4.2 Rigid paving - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - 6 External references
6 External references - Introduction
Introduction - The methods of constructing roads have changed a lot since the first roads were built around 4,000 BC made of stone and timber.
The methods of constructing roads have changed a lot since the first roads were built around 4,000 BC made of stone and timber.
The first Roman roads were stone paved, built in North Africa and Europe for military operations. Road construction techniques were gradually improved by the study of road traffic, stone thickness, road alignment, and slope gradients, developing to use stones that were laid in a regular, compact design, and covered with smaller stones to produce a solid layer.
Modern roads tend to be constructed using asphalt and/or concrete.
Very broadly, the construction of roads can be described by three processes:
Setting out. - Earthworks.
Earthworks. - Paving construction.
Paving construction. - Setting out
Setting out - This is carried out following the dimensions specified in layout drawings.
This is carried out following the dimensions specified in layout drawings.
A commonly used setting out procedure is the profile board method. A series of boards that show the exact level 1 metre above the completed construction level are placed at intervals along the proposed line of the road. A profile board with a fixed height, called the traveller, is used for controlling the excavated levels between these profile boards. By placing the traveller in the sight-line between two level boards, it can be seen whether or not the excavation has been carried out to correct levels and adjusted accordingly.
The level of each profile board is controlled using a line level which is a short spirit level hung from a nylon string. The line operator moves the string up or down until the bubble is centred.
Junctions, hammer heads, turning bays and intersecting curves are laid out in a similar manner.
Earthworks - Earthwork is one of the major works involved in road construction. It involves the removal of topsoil, along with any vegetation, before scraping and grading the area to the finished formation level. This is usually done using a tractor shovel, grader or bulldozer. Below the formation level, the soil is known as the subgrade. It is essential that the strength of the subgrade is tested prior to earthwork beginning.
Earthwork is one of the major works involved in road construction. It involves the removal of topsoil, along with any vegetation, before scraping and grading the area to the finished formation level. This is usually done using a tractor shovel, grader or bulldozer. Below the formation level, the soil is known as the subgrade. It is essential that the strength of the subgrade is tested prior to earthwork beginning.
Most earthworks are formed by cut-and-fill, and the type of fill material must be considered, not only in terms of its physical properties, but on the conditions in which it is to be used, and the methods of compaction.
Depending on its quality, compressible subsoil may be removed or stabilised. If the cost of full or partial excavation of subsoil is uneconomical and would be likely to result in consolidation, sand wicks or sand drains may be used. Sand wicks are sand-filled boreholes beneath the road embankment that give greater stability to the soil by decreasing the length that water has to travel in a drainage path, so dissipating water pressure. Sand drains alongside the road are used to intercept ground water.
Subsoil drainage should be provided to deal with seepage through pavements and verges, from higher ground and a result of the seasonal rise and fall of the water table.
Subgrade strength - The required thickness of the pavement is determined by the subgrade strength, so it is desirable to make the subgrade as strong as possible.
The required thickness of the pavement is determined by the subgrade strength, so it is desirable to make the subgrade as strong as possible.
The strength of the subgrade can be achieved by using the following techniques:
Removal of poor material in cuttings and replacing with selected fill.
Compacting subgrade to a high dry density. - Providing adequate subsoil drainage.
Providing adequate subsoil drainage. - Soil stabilisation methods such as the use of cement, bituminous materials or chemicals.
Soil stabilisation methods such as the use of cement, bituminous materials or chemicals.
For more information, see Types of soil.
The subgrade strength will decrease as moisture content increases so protection may be required if it is to left exposed for any length of time.
Protection covering can be either: -
Medium gauge plastic sheeting with 300 mm laps.
Sprayed bituminous binder with a sand topping. - Paving construction
Paving construction - Once the subgrade has been prepared and drainage or buried services installed, the paving construction can begin. Paving can be either flexible or rigid. There are pros and cons to each type, with one being selected over the other depending on the specific needs of a project.
Once the subgrade has been prepared and drainage or buried services installed, the paving construction can begin. Paving can be either flexible or rigid. There are pros and cons to each type, with one being selected over the other depending on the specific needs of a project.
Rigid pavements tend to have lower maintenance costs, a longer design life and higher flexural strength; but flexible pavements tend to have lower construction costs and have a higher ability to expand and contract with temperature and so do not need expansion joints.
Flexible paving - Flexible paving consists of materials applied in layers directly over the subgrade to which the traffic loads are distributed. To prevent permanent deformation, and therefore an uneven running surface, the thicknesses of individual layers must be capable of distributing such loads. The subgrade is compacted with the sub-base on top of it. On top of this is laid the surfacing which is made up of the base layer and the wearing course.
Flexible paving consists of materials applied in layers directly over the subgrade to which the traffic loads are distributed. To prevent permanent deformation, and therefore an uneven running surface, the thicknesses of individual layers must be capable of distributing such loads. The subgrade is compacted with the sub-base on top of it. On top of this is laid the surfacing which is made up of the base layer and the wearing course.
Surfacing - The wearing course is the upper layer of bituminous material, often denser and stronger than the base layer. The thickness depends on the material specification and the amount of wear that is expected. Desired properties are good non-skid capabilities, minimal glare and acceptable durability.
The wearing course is the upper layer of bituminous material, often denser and stronger than the base layer. The thickness depends on the material specification and the amount of wear that is expected. Desired properties are good non-skid capabilities, minimal glare and acceptable durability.
The main materials that are used are hot rolled asphalt (HRA), dense bitumen macadam (DBM), dense tar macadam (DTM) and porous asphalt (PA). PA is especially suitable as it is an open-graded material that is designed to allow rapid drainage of surface water, thereby reducing spray as well as tyre noise.
The base will typically have a minimum thickness of 60 mm and is usually made of dense bitumen macadam or asphalt. It is laid with the appropriate crossfalls and gradients.
Sub-base - This is placed in a layer usually not exceeding 150 mm over the subgrade after waterproofing is complete. Various materials can be used but it is common for crushed stone or dry lean concrete (such as 1 : 15) laid and compacted by heavy rollers.
This is placed in a layer usually not exceeding 150 mm over the subgrade after waterproofing is complete. Various materials can be used but it is common for crushed stone or dry lean concrete (such as 1 : 15) laid and compacted by heavy rollers.
Rigid paving - Rigid paving consists of a reinforced or unreinforced insitu concrete slab laid over a thin granular base course. The rigidity and strength of the pavement enables the loads and stresses to be distributed over a wide area of the subgrade.
Rigid paving consists of a reinforced or unreinforced insitu concrete slab laid over a thin granular base course. The rigidity and strength of the pavement enables the loads and stresses to be distributed over a wide area of the subgrade.
Rigid paving is made up of the following layers (from top to bottom):
Subgrade. - Sub-base of thick crushed stone. Usually to a thickness of 80 mm.
Sub-base of thick crushed stone. Usually to a thickness of 80 mm.
Anti-friction membrane normally made of polythene sheeting. Also prevents grout loss from freshly laid concrete.
Insitu concrete paving slab. Reinforcement in the form of either steel fabric or re-bar may be used.
Asphalt or similar topping if required. - Longitudinal and transverse joints are required in rigid paving between the slabs, limiting the stresses applied due to subgrade restraint (friction between the pavement and subgrade), and providing room for expansion and contraction movements. The spacing of road joints is determined by:
Longitudinal and transverse joints are required in rigid paving between the slabs, limiting the stresses applied due to subgrade restraint (friction between the pavement and subgrade), and providing room for expansion and contraction movements. The spacing of road joints is determined by:
Thickness of the slab. - Whether there is reinforcement in the slab or not.
Whether there is reinforcement in the slab or not.
The expected traffic load and flow rate. - The temperature at which concrete is laid.
The temperature at which concrete is laid. - For more information, see Road joints.
For more information, see Road joints. -
For more information, see Highway drainage. -
For more information, see Kerbs. -
Benchmarking in the construction industry - A benchmark is a pre-determined standard or point of reference against which other things, people, costs, time or activities can be measured. It is regarded as an achievable standard which a failure to achieve could deem the work in question to be unsatisfactory.
A benchmark is a pre-determined standard or point of reference against which other things, people, costs, time or activities can be measured. It is regarded as an achievable standard which a failure to achieve could deem the work in question to be unsatisfactory.
In any industry, a benchmark can constitute a method of instigating best practice and is usually designed to lead to higher standards.
NB On a construction site, a physical benchmark can be represented by a mark, whether on a concrete post set into the ground or some other permanent marker indicating a site datum to which all vertical levels and elevations will relate to. It is the point of reference that surveyors use for levelling and on which drawings by architects, engineers, contractors and subcontractors are based. The Ordnance Bench Mark is an officially established mark that links back to the Ordnance Datum a theoretical level zero which is assumed to be the mean sea level at Newlyn, Cornwall. From this base point, all Ordnance Survey heights above sea level (such as contours) are related, as are geologic surveys and tidal observations.
Project benchmarking - Project benchmarking is a process by which the estimated performance (such as cost) of a project is compared to other similar projects. This can highlight areas of the design that are not offering good value for money and can help in the assessment of tenders from suppliers and contractors.
Project benchmarking is a process by which the estimated performance (such as cost) of a project is compared to other similar projects. This can highlight areas of the design that are not offering good value for money and can help in the assessment of tenders from suppliers and contractors.
Some websites allow construction professionals to benchmark their projects performance against construction industry standards generally. This system may use the nationally-recognised Constructing Excellence construction KPIs a system of benchmarks used for performance measurement and productivity. By measuring and comparing a project or organisational performance against these benchmarks it is possible to identify areas in which it is possible to improve or to demonstrate excellence.
Benchmarking is increasingly carried out on public projects, as the government has access to large amounts of data for similar projects. For example, when analysis of the Buildings Schools for the Future programme was carried out, it exposed variations in costs that could not be justified by project differences.
Proposals are being considered that will see cost benchmarking carried out across all government capital programmes to create baselines for a cost/value-led approach to procurement.
For more information see: Project benchmark. -
The term 'architect' has been used for many centuries, but the architect as a recognised profession is a relatively modern concept dating back to the mid 16th century, from the French architecte and Italian architetto (originating from the Greek arkhitekton, where arkhi means 'chief' and tekton 'builder'). The term and what it represents has evolved through history to its current form in which architects are seen as highly-qualified and educated professionals.
See The History of the architect as a profession for more information.
Regulation of architects - Although buildings in the UK are commonly designed by people who are not architects, the term architect itself is protected by the Architects Act 1997 which established the Architects Registration Board (ARB). Only qualified individuals that are registered with the ARB can offer their services as architects. Section 20 of the Architects Act states that 'A person shall not practise or carry on business under any name style or title containing the word architect unless he is a person registered under this Act'.
Although buildings in the UK are commonly designed by people who are not architects, the term architect itself is protected by the Architects Act 1997 which established the Architects Registration Board (ARB). Only qualified individuals that are registered with the ARB can offer their services as architects. Section 20 of the Architects Act states that 'A person shall not practise or carry on business under any name style or title containing the word architect unless he is a person registered under this Act'.
The ARB has responsibility for: -
Recognising qualifications. - Maintaining a list of registered architects and ensuring that people not on the list do not offer their services as an architect.
Maintaining a list of registered architects and ensuring that people not on the list do not offer their services as an architect.
Monitoring standards and investigating complaints. - ARB issues a code of conduct for architects and can take action against those falling short of the codes standards.
ARB issues a code of conduct for architects and can take action against those falling short of the codes standards.
Architects can also become chartered members of the Royal Institute of British Architects (RIBA), but this is voluntary and is not necessary to practice as an architect.
See The History of the architect as a profession for more information.
In November 2020, the government announced a consultationon changes to the Architects Act to make competence assesssment compulsory. For more information see: Architects' building safety competence consultation.
Training - The most common route into the profession is through university study, broken down into 3 parts:
The most common route into the profession is through university study, broken down into 3 parts:
Part 1 Honours degree in architecture, followed by 1 year out in practice under the guidance of an architect and monitored and recorded in line with RIBA requirements.
Part 2 - Masters, Diploma or BArch (depending on the individual school) taught in university for 2 to 3 years, followed by a further monitored and recorded year in practice.
Part 3 - the RIBA final exam. - The RIBA Examination in Architecture for Office-based Candidates is an alternative route to qualification for Part 1 and Part 2 for people working full-time under the supervision of an architect. Applicants must have a minimum of three years experience in architectural practice to join the examination at Part 1; or 3 years post-Part 1 experience to join the Part 2 stage (as well as holding Part 1).
The RIBA Examination in Architecture for Office-based Candidates is an alternative route to qualification for Part 1 and Part 2 for people working full-time under the supervision of an architect. Applicants must have a minimum of three years experience in architectural practice to join the examination at Part 1; or 3 years post-Part 1 experience to join the Part 2 stage (as well as holding Part 1).
Recently, there is concern that architectural training has become relatively expensive as universities can charge fees of up to 9,000 a year. Training to become an architect takes at least seven years, with four or five of these at university. Adding in necessary living expenses on top of university fees, it is thought that the total cost of training to become an architect could be as much as 100,000.
This may result in architecture becoming the preserve of students whose parents are able to support them through their training. Whilst the number of applications for places at schools of architecture remains high, increasingly this is from students outside the EU, with applications from UK and EU students decreasing.
NB On 27 June 2018, the Institute for Apprenticeships approved standards and end point assessment documents for an architectural assistant apprenticeship, which encompasses a Part 1 qualification, and an architect apprenticeship, which encompasses a Part 2 qualification and a Part 3 qualification. Ref http://ebulletin.arb.org.uk/july2018/degree-apprenticeships/
See architectural training for more information. -
For the types of modules that students study as part of architecture degree courses, see Architecture course essentials.
The term engineer is a very broad one, covering a wide range of disciplines who use the sciences and mathematics to develop solutions for technical applications. Typically on a construction project, a structural engineer and building services engineer will be part of the core consultant team.
To see some of the modules studied as part of an engineering degree course, see Construction engineering management course essentials.
Building services engineers plan, design, monitor and inspect systems to make buildings comfortable, functional, efficient and safe. Typically these systems will include heating, ventilation and air conditioning (HVAC), water and drainage, lighting, power, ICT, lifts and escalators, control systems, and so on.
Complex buildings such as airports, hospitals, factories and laboratories may require additional systems such as specialist gas distribution, humidity and bacteria control and so on.
For more information, see Building services and Building services engineer.
Structural engineer - Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineering was traditionally considered a sub-discipline of civil engineering, however, as it has developed into an important and complex specialism it may now be considered an engineering discipline in its own right.
Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineering was traditionally considered a sub-discipline of civil engineering, however, as it has developed into an important and complex specialism it may now be considered an engineering discipline in its own right.
Structural engineers work on a very wide range of structures, including; buildings, bridges, oil rigs, ships and aircraft. It is both a technical and creative role that involves close collaboration with professionals from other disciplines.
For more information, see Structural engineer. -
Drainage is the artificial removal of water, both surface and sub-surface. Drainage is often a major element of civil engineering and construction projects and is necessary to avoid flooding and other damage.
Typically, effluent is conveyed by drains to sewers, and from sewers to a suitable outfall or treatment plant. In building drainage terms, effluent can refer to the following:
Subsoil water - This is water collected from the earth to lower the subsoils water table.
This is water collected from the earth to lower the subsoils water table.
Surface water - This is collected from surfaces such as roofs and paved areas.
This is collected from surfaces such as roofs and paved areas.
Foul and soil water - This is effluent contaminated by domestic or trade waste. Foul (or waste) water relates to effluent from sinks and basins which does not contain excreta. Soil water relates to effluent from water closets, toilets and urinals which does.
This is effluent contaminated by domestic or trade waste. Foul (or waste) water relates to effluent from sinks and basins which does not contain excreta. Soil water relates to effluent from water closets, toilets and urinals which does.
Subsoil and surface water are considered to be clean and can be discharged into an approved watercourse (e.g. river or lake), or soakaway without treatment. Permission is required from the relevant authority or owner before discharging. Foul and soil water must be conveyed by sewer to a treatment plant before being discharged into a watercourse.
Subsoil drainage - Subsoil drainage can be used to improve ground stability, to lower the moisture content of a site, to enhance horticultural properties for landscaping and so on. It can be required to drain the whole site or to protect a particular part.
Subsoil drainage can be used to improve ground stability, to lower the moisture content of a site, to enhance horticultural properties for landscaping and so on. It can be required to drain the whole site or to protect a particular part.
According to the Approved Document C of the Building Regulations, subsoil drainage should be provided to avoid the passage of ground moisture into a buildings interior or to prevent damage being caused to the buildings fabric.
Subsoil drainage is generally involves the use of pipes that are porous to allow subsoil water to pass through the pipe body, or pipes that are perforated with a series of holes in the lower half to allow subsoil water to rise into the pipe. Both types are generally laid dry jointed in a trench filled with rubble. A pervious membrane is generally placed on top of the rubble as a filter mat, then covered with normal backfill and topped with 150 mm of topsoil.
This type of groundwater control is only feasible up to a depth of 1.5 m, and any further lowering of the water table should be achieved by other methods. For more information, see Groundwater control in urban areas.
When drainage is used to protect a buildings substructure, a cut off drain is generally installed that intercepts the flow of water and diverts it away from the site.
Surface water drainage - Roofing
Roofing - It is a requirement of Building Regulations Approved Document H that adequate provision is made for rainwater to be carried from the roof of buildings. To achieve this, roofs must be designed with a suitable fall towards either a surface water collection channel or gutter that conveys surface water to vertical rainwater pipes, which in turn connect the discharge to the drainage system.
It is a requirement of Building Regulations Approved Document H that adequate provision is made for rainwater to be carried from the roof of buildings. To achieve this, roofs must be designed with a suitable fall towards either a surface water collection channel or gutter that conveys surface water to vertical rainwater pipes, which in turn connect the discharge to the drainage system.
The type of roof covering used determines the required fall of the roof. Minimum recommended falls are typically:
Aluminium 1:60. - Lead 1:120.
Lead 1:120. - Copper 1:60.
Copper 1:60. - Roofing felts 1:60.
Roofing felts 1:60. - Mastic asphalt 1:80.
Mastic asphalt 1:80. - Standards 'flat' roofs should have a designed minimum fall of 1:40, so that an actual finished fall of 1:80 is achieved, allowing some room for error in the construction.
Standards 'flat' roofs should have a designed minimum fall of 1:40, so that an actual finished fall of 1:80 is achieved, allowing some room for error in the construction.
Rainwater installation - Drainage from roofs is generally provided by internal rainwater outlets and downpipes, or by external guttering systems or hoppers. It is recommended that there are at least two drainage points, even if the roof is small, to mitigate against one of them becoming blocked.
Drainage from roofs is generally provided by internal rainwater outlets and downpipes, or by external guttering systems or hoppers. It is recommended that there are at least two drainage points, even if the roof is small, to mitigate against one of them becoming blocked.
Drainage must be arranged so as to avoid causing dampness or damage to the building. If the rainwater pipe is fitted internally it must have leak proof joints. If external, the roofing should prevent water being blown into the eaves by extending into and below the top of the gutter.
The discharge from a building downpipe can be:
Directly connected to a drain discharging into a soakaway.
Directly connected to a drain discharging into a surface water sewer.
Indirectly connected to a drain via a trapped gully if the drain discharges into a combined sewer.
Traditionally, domestic eaves gutters and rainwater pipes were made using cast iron, although uPVC systems are increasingly common due to ease of installation and low maintenance requirements. As long as adequate size, strength and durability can be assured, they can also be made of aluminium alloy, galvanised steel, stainless steel and so on.
Paved areas - Paved areas are generally provided with one of two forms of surface water drainage.
Paved areas are generally provided with one of two forms of surface water drainage.
Yard gully collection - A paved area near a building is laid to falls of 1:60 towards a gully. The type of area being drained and the shape of the paved area will determine the size and number of gullies. The maximum paved area per gully should be 400 sq. m. If it is connected to a combined sewer, the yard gully should be trapped with a minimum 50 mm water seal.
A paved area near a building is laid to falls of 1:60 towards a gully. The type of area being drained and the shape of the paved area will determine the size and number of gullies. The maximum paved area per gully should be 400 sq. m. If it is connected to a combined sewer, the yard gully should be trapped with a minimum 50 mm water seal.
Channel connection - The paving, laid to the same falls, drains away from a building to a channel laid to falls of 1:120. The channel is connected to the drainage system. The channel is typically:
The paving, laid to the same falls, drains away from a building to a channel laid to falls of 1:120. The channel is connected to the drainage system. The channel is typically:
Half-round glazed clayware channel: Either open or with a grating cover.
Precast concrete channel blocks: With a continuous slot down the centre of the top.
Precast or in situ concrete box channel: With a cast iron square mesh grating.
Highway drainage - The construction of roads affects the natural surface and subsurface drainage pattern of watersheds or hill-slopes. The provision of adequate drainage is important to prevent the accumulation of excess water or moisture on or within road constructions that can adversely affect their material properties, compromise overall stability and affect driver safety. Drainage must cope with water from the carriageways, hard shoulders, foot/cycle paths, verges, and adjacent catchment areas.
The construction of roads affects the natural surface and subsurface drainage pattern of watersheds or hill-slopes. The provision of adequate drainage is important to prevent the accumulation of excess water or moisture on or within road constructions that can adversely affect their material properties, compromise overall stability and affect driver safety. Drainage must cope with water from the carriageways, hard shoulders, foot/cycle paths, verges, and adjacent catchment areas.
For more information, see Highway drainage. -
Sustainable urban drainage systems - Sustainable urban drainage systems (SUDS) can provide an alternative to, or addition to, traditional drainage systems. They mimic 'natural' drainage by adopting techniques to deal with surface water runoff locally, through collection, storage, and cleaning before allowing it to be released slowly back into the environment.
Sustainable urban drainage systems (SUDS) can provide an alternative to, or addition to, traditional drainage systems. They mimic 'natural' drainage by adopting techniques to deal with surface water runoff locally, through collection, storage, and cleaning before allowing it to be released slowly back into the environment.
The word effluent refers to liquid waste or sewage.
Event effluent is: 'The combination of inventory and any firefighting water and/or foam and rainwater arising from an event.'
Trade effluent is: Any liquid waste, other than surface water and domestic sewage that is discharged from premises being used for business, trade or industry.
Ref Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014.
Sewerage (the sewer system), is the underground networks of pipes that carries sewage (waste water and excrement), waste water and surface water run-off, from buildings to treatment facilities or disposal points.
A sewer is; 'A pipe or channel taking domestic foul and/or surface water from buildings and associated paths and hardstandings from two or more curtilages and having proper outfall' Ref The SuDS Manual (C753), published by CIRIA in 2015.
Types of sewer include: -
Sanitary sewer: Used solely for carrying sewage.
Surface water sewer: Used to drain groundwater and excess water from impervious surfaces.
Combined sewer: Used to carry both sewage and surface water. This type of sewer can lead to water pollution problems when overflow conditions are experienced.
Effluent sewer (sometimes referred to as Septic Tank Effluent Drainage (STED) or Solids-Free Sewers (SFS)) : These collect remaining sewage from septic tanks and carry it to a treatment plant.
Separate sewer: For surface water or foul sewage, but not a combination of both.
There are a number of ways of moving the contents of sewers:
Gravity sewers use differing elevations to facilitate movement.
Force mains use pumps where sewers are at a lower elevation than the destination.
Vacuum sewers use differential atmospheric pressure. - A sewerage undertaker is: 'A collective term relating to the statutory undertaking of water companies that are responsible for sewerage and sewage disposal, including surface water from roofs and yards of premises.' Ref The SuDS Manual.
A sewerage undertaker is: 'A collective term relating to the statutory undertaking of water companies that are responsible for sewerage and sewage disposal, including surface water from roofs and yards of premises.' Ref The SuDS Manual.
In September 2010, the government announced that most private sewers that connected to the public sewer network would be transferred to the ownership of the regulated sewerage companies in England and Wales. Private sewers that were connected to the public sewer network before 1 July 2011 were transferred on 1 October 2011.
The term units can have several different applications in the context of the built environment.
The term can refer to devices that form part of a more complex mechanism and have a specified function. For example; air handling units, chiller units, consumer units, fan coil units and so on.
It can also refer to a unit of measurement, which is used as a standard for measuring similar items. When any other quantity of the same kind is measured it can be expressed in those units. For example, the physical quantities of length or height. Metres, centimetres and millimetres are units of length that represent a definite predetermined length. In other words, 5 metres refers to five times the predetermined length of a metre.
The International System of Units (SI) is the most commonly adopted system of units.
Public project definition - The term 'public project' is an ambiguous one, but in very broad terms, it refers to a project that is financed by a government and is typically owned, and may be operated by the government. This can include major infrastructure works such as roads, bridges, dams, railways, tunnels, and so on, or public facilities such as hospitals, schools, prisons, libraries, leisure centres, and so on.
The term 'public project' is an ambiguous one, but in very broad terms, it refers to a project that is financed by a government and is typically owned, and may be operated by the government. This can include major infrastructure works such as roads, bridges, dams, railways, tunnels, and so on, or public facilities such as hospitals, schools, prisons, libraries, leisure centres, and so on.
As public projects are generally funded by tax revenue, they are typically subject to a greater level of scrutiny, and greater transparency is required in the bidding and contract award procedures. Public projects often publish their requirements and request bids openly, with received bids considered in an open and transparent way. The government can also stipulate certain criteria that a supplier must fulfil in order to be awarded a public contract, such as; minimum wage levels, reporting procedures, and so on.
The European Union Procurement Directives establish public procurement rules throughout the European Union which apply to any public purchases above the defined thresholds. Public projects must comply with the regulations if the value of contracts is above those thresholds. Private projects may also be required to comply with the regulations if they are publicly subsidised.
See OJEU procurement procedures for more information. -
In the UK, a public building is narrowly defined as a building that is 'occupied by a public authority and frequently visited by the public'. See Public building definition for more information.
Designing Buildings Wiki has an outline work plan setting out the tasks necessary to complete a public project, which you can find here.
Structure definition - Within the context of the built environment , the term structure refers to anything that is constructed or built from different interrelated parts with a fixed location on the ground.
Within the context of the built environment , the term structure refers to anything that is constructed or built from different interrelated parts with a fixed location on the ground.
This includes buildings, but the term structure can also be used to refer to any body of connected parts that is designed to bear loads, even if it is not intended to be occupied by people. Engineers sometimes refer to these as 'non-building' structures. Common examples include:
Aqueducts and viaducts. - Bridges.
Bridges. - Canals.
Canals. - Cooling towers and chimneys.
Cooling towers and chimneys. - Dams.
Dams. - Railways.
Railways. - Roads.
Roads. - Retaining walls.
Retaining walls. - Tunnels.
Tunnels. - Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineers work on a very wide range of structures, including; buildings, bridges, oil rigs, and so on.
Structural engineers design, assess and inspect structures to ensure that they are efficient and stable. Structural engineers work on a very wide range of structures, including; buildings, bridges, oil rigs, and so on.
Civil engineers design, construct, maintain and improve the physical environment, including bridges, tunnels, roads, railways, canals, dams, coastal defences, and so on. The term civil engineer is a more broad one than structural engineer that can include infrastructure such as pipelines, transportation, environmental engineering, maritime engineering, and so on. It was originally coined to distinguish it from military engineering.
Structural engineering was initially considered a sub-discipline of civil engineering, however it has developed into an important and complex specialism and is now be considered an specific engineering discipline in its own right.
According to William R Spillers 'Introduction to Structures', structural analysis is for the most part concerned with finding the structural response (the lateral deflection of a building under wind load, the reaction of a bridge to a moving train,) given external loads. In all but the most trivial cases, real structures, that is structures without the simplifications commonly associated with analysis, turn out to be impossibly complex. And what is finally analysed the structural model may appear at first glance to be quite different than the real structure.
In their most simple form, structural elements can be classified as:
One-dimensional: Ropes, struts, beams, arches.
Two-dimensional: Membranes, plates, slab, shells, vaults.
Three-dimensional: Solid masses. - Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, paragraph B3.iii defines elements of structure as:
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, paragraph B3.iii defines elements of structure as:
.the main structural loadbearing elements, such as structural frames, floors and loadbearing walls. Compartment walls are treated as elements of structure although they are not necessarily loadbearing. Roofs, unless they serve the function of a floor, are not treated as elements of structure. External walls, such as curtain walls or other forms of cladding which transmit only self weight and wind loads and do not transmit floor load, are not regarded as loadbearing
Very broadly, the 'substructure' refers to work below the underside of the screed or, where no screed exists, to the underside of the lowest floor finishes, and the 'superstructure includes works above that level. See Substructure and Superstructure for more detailed definitions.
NB The CDM Regulations suggest that structure means:
(a) any building, timber, masonry, metal or reinforced concrete structure, railway line or siding, tramway line, dock, harbour, inland navigation, tunnel, shaft, bridge, viaduct, waterworks, reservoir, pipe or pipeline, cable, aqueduct, sewer, sewage works, gasholder, road, airfield, sea defence works, river works, drainage works, earthworks, lagoon, dam, wall, caisson, mast, tower, pylon, underground tank, earth retaining structure or structure designed to preserve or alter any natural feature and fixed plant;
(b) any structure similar to anything specified in paragraph (a);
(c) any formwork, falsework, scaffold or other structure designed or used to provide support or means of access during construction work,
and any reference to a structure includes part of a structure.
RICS property measurement, 2nd edition, published by the Royal Institution of Chartered Surveyors (RICS) in January 2018, defines a structure as: A construction that provides shelter or serves an ancillary function, but is not necessarily fully enclosed.
Tension is a state of stress in which a material is being pulled apart, for example a cable that is attached to a ceiling with a weight fixed to its lower end. Under the influence of gravity, the weight exerts a downward pressure that produces tension in the cable, as does the reaction at the fixing point in the ceiling.
A similar effect will be produced by two people each holding one end of a length of rope and pulling hard. Another example is a lift car that is moved by steel cables the fibres in the cables will tend to be pulled apart by the weight of the lift car.
In both the above cases, the fibres become longer as a result of the weight applied. When a unit length of material becomes elongated, it is termed tensile strain.
As long as the cable is not stressed above its elastic range, the extent of lengthening will depend on its cross section, its length and the load applied. The larger the cable diameter, the smaller the unit elongation. Experiments have shown that elongation is inversely proportional to the area, so a member of 20mm2 cross-sectional area will stretch half the amount of a member of the same material that is 10mm2.
Hookes Law states that an increase in the load produces a proportionate increase in elongation and that this elongation is directly proportional to the length of the member. So, for a given load and given length of member, a member 2m-long will stretch twice as much as a 1m-long member of the same material.
In addition to elongation (the main consequence) other deformations may occur when a material is subjected to simple tension. If a material is carefully measured before and after a load is applied, it is observed that with the increase in load and the accompanying elongation, there is also an increase in diameter. This phenomenon was first observed by the French 19th century physicist Poisson.
Poissons ratio is the relationship between the lateral strain and horizontal strain. For steel it is around 0.33.
Tension has different effects on materials: concrete does not accommodate tensile stresses well and may crack and suffer extensive damage with little elongation; while steel is very strong in tension and can elongate substantially under load. It is for this reason that concrete is often reinforced with steel rebar.
The opposite of tension is 'compression' which sees materials pushed or compressed together when a compressive force is applied.
Structures with tension elements include: -
Fabrics structures. - Cable net structures.
Cable net structures. - Suspension bridges.
Suspension bridges. - Three-dimensional tensile structures typically form doubly-curved shapes that are either anticlastic or synclastic.
Three-dimensional tensile structures typically form doubly-curved shapes that are either anticlastic or synclastic.
Location -
In terms of geography and the built environment, the term location is used to refer to a point or area on the Earths surface. It is commonly used to imply more geometrical certainty than place which tends to be used to indicate somewhere with a boundary that can be ambiguous. It also differs to space, which is more abstract and tends to be used to refer to a location without human value or meaning having been attached to it.
Location can be defined in a number of ways:
Relative location: Described as displaced from another point, e.g. 10 miles south of [place].
Locality: An area, usually highly populated, that has an ambiguous boundary, e.g. Greater London.
Absolute location: Uses a Cartesian coordinate grid (e.g. the World Geodetic System) to plot latitudes and longitudes.
In terms of property development and real estate, the common mantra is location, location, location, which is used to emphasise the importance and centrality of location. This mantra refers to the fact that, typically, similar buildings (e.g. houses) can increase or decrease in value depending on their location, and that while structures can be improved, renovated, decorated, and so on, or its use class changed, its location cannot be changed.
However, in certain circumstances a structure can be moved from one place to another, in a process known as relocation. This can be done either by disassembling the structure and reassembling it in a new position, or by transporting it in its entirety. This is, though, a complex process and is often prohibitively expensive. For more information, see Structure relocation.
Some of the factors that can characterise a prime location include:
Good transport infrastructure links. - Good quality schools, hospitals and other public services in the vicinity.
Good quality schools, hospitals and other public services in the vicinity.
Somewhere close to recreation sites and areas of natural beauty, green spaces, and so on.
Properties that have good views. - Close proximity to cultural, entertainment, shopping and leisure hubs.
Close proximity to cultural, entertainment, shopping and leisure hubs.
Economically-stable areas (those where properties have held their value over time).
Low levels of crime, pollution and noise.
Some of the factors that can characterise a bad location include:
Close proximity to commercial, industrial or agricultural areas.
Close proximity to railway tracks, busy roads or flight paths.
High levels of crime, pollution and noise.
Close proximity to an 'eyesore' such as a brownfield site.
Noise or other pollution. - Lack of natural light, ventilation, etc.
Lack of natural light, ventilation, etc.
Economically depressed or volatile areas. - Areas with poor public services, transport links, job opportunities, and so on.
Areas with poor public services, transport links, job opportunities, and so on.
A location plan is a supporting document that may be required by a planning authority as part of a planning application. A location plan provides an illustration of a development in its surrounding context. This enables the planning authority to properly identify the land to which the application refers, and is typically based on an up-to-date Ordnance Survey (or similar) map.
Warranty - The term 'warranty' can have a number of meanings, but in general, it refers to a legally binding assurance or promise.
The term 'warranty' can have a number of meanings, but in general, it refers to a legally binding assurance or promise.
Warranties may be used to provide assurance from one party to another that goods and/or services will meet certain expectations, e.g. fit for purpose, being free from defects, complying with statutory and other regulations and specifications.
A warranty can be either express (i.e. written) or implied.
A common form of warranty, and one that is paid for, is that which runs with a product, meaning that the customer of a product is given an assurance by the manufacturer that any defects or losses will be repaired or compensated during a given period. The warranty can also detail both parties rights and obligations in the event of a dispute.
Defects in buildings are not recoverable in tort (only as a contractual claim), as they are economic loss which are only recoverable through a contractual relationship. As a result, collateral warranties have been developed. These provide for a duty of care to be extended by one of the contracting parties to a third party who is not party to the original contract.
A typical example is an architect of a new development agreeing to a duty of care to the occupant. Privity of contract rules would prevent any liability arising between the architect and occupier without the existence of a collateral warranty.
For more information see: Collateral warranties. -
Bonds and guarantees are forms of security that accompany contractual obligations and are based on either primary or secondary obligations.
For more information, see Guarantees. -
Other forms of assurance that might be referred to on construction projects include:
Fitness for purpose. - Reasonable skill and care.
Reasonable skill and care. - Workmanlike manner.
Workmanlike manner. - Good faith.
Good faith. - Reasonable endeavours.
Reasonable endeavours. - Best endeavours.
Best endeavours. - Retention.
Retention. - Duty of care.
Duty of care. -
A block plan usually shows the siting of buildings as blocks laid out on maps of the surrounding area. A range of standard mark ups can be used to depict boundaries, roads and other details.
Depending on the size of the project, typical scales of block plans are:
1 : 2500 - 1 : 1250
1 : 1250 - 1 : 500
1 : 500 - It is common for the term block plan to be used interchangeably with site plan. They are both similar in that they illustrate the development site along with the position of the proposed building(s), as well as any access roads, vegetation, utilities, and so on. They typically indicate the development site and access in red outline, as well as any other land owned by the developer in blue outline.
It is common for the term block plan to be used interchangeably with site plan. They are both similar in that they illustrate the development site along with the position of the proposed building(s), as well as any access roads, vegetation, utilities, and so on. They typically indicate the development site and access in red outline, as well as any other land owned by the developer in blue outline.
However, a site plan generally shows in more detail the contents and extent of the site for an existing or proposed development, whereas a block plan shows less detail of the site and more of the surrounding area. In planning applications, block plans can help the local authority determine the possible impacts that the proposed project may have on the wider area.
If it is a large site or if a wider indication of the impact on the surrounding area is necessary, then a location plan may be prepared, identifying where the site is, but giving little detail for the development itself.
Space planning - Space planning is an important part of building design and is used to determine how a space (or spaces) should be laid out and used. It may be undertaken as part of the building design process, or as a stand alone exercise looking at how best to plan an existing space, or a space that is being developed (for example, a tenant determining how to fit out their part of a new development). It can be used for very simple spaces such as hotel bedrooms, through to very complex industrial buildings.
Space planning is an important part of building design and is used to determine how a space (or spaces) should be laid out and used. It may be undertaken as part of the building design process, or as a stand alone exercise looking at how best to plan an existing space, or a space that is being developed (for example, a tenant determining how to fit out their part of a new development). It can be used for very simple spaces such as hotel bedrooms, through to very complex industrial buildings.
Good space planning can improve the wellbeing and productivity of the occupants of a space.
Designers will consult with the client to clarify their requirements for the space before starting planning (and perhaps assess existing spaces), typically by considering issues such as:
Budget and time constraints. - The separation of activities into zones.
The separation of activities into zones. - The intended use/s of the space.
The intended use/s of the space.
The number of occupants. - The space required per occupant.
The space required per occupant. - The main focal points of the space.
The main focal points of the space. - The need for or availability of windows and doors.
The need for or availability of windows and doors.
Access into and from the space, and the function of adjacent spaces.
Circulation within the space. - Access and use of the space for people with disabilities.
Access and use of the space for people with disabilities.
The requirement for furniture, fixtures and fittings.
The number of people who are likely to use the space.
Whether the space should be balanced and symmetrical, unbalanced or a combination.
Security, safety and privacy. - Legislative requirements.
Legislative requirements. - Lighting IT and other building services requirements.
Lighting IT and other building services requirements. - Energy targets and sustainability requirements.
Energy targets and sustainability requirements. - Environmental requirements, such as noise, lighting, ventilation, temperature, and so on.
Environmental requirements, such as noise, lighting, ventilation, temperature, and so on.
Environmental controls. - Welfare facilities.
Welfare facilities. - Views.
Views. - Colours and branding.
Colours and branding. - Planting.
Planting. - The need for flexibility or future growth.
The need for flexibility or future growth. - Once considerations such as those listed above have been resolved, a space plan can be created.
Once considerations such as those listed above have been resolved, a space plan can be created.
There are various techniques that can be used to create a space plan. A common early technique is the bubble plan. This involves drawing a plan of the space and using bubbles, or circles, to roughly delineate the various activities that will take place, overlapping according to the relationship between them.
Once the activities have been defined and located in relation to one another, a more detailed scale plan can be drawn to show the layout of individual items within the space. This process can be carried out by hand, or with moveable paper cut outs, or using space planning software such as computer aided design (CAD) software or building information modelling software (BIM).
Parametric modelling can simplify space planning by allowing the automatic application of pre-defined rules to the entire space. So for example, if a colour scheme for particular part of the space is changed, every object that has that colour attribute will also change. Other parameters might include; positional data, dimensions, algorithms describing form, and so on.
In particularly complex spaces, techniques such as space syntax can allow the relationships between spatial layout and human behaviour to be simulated and investigated in detail. This might be useful, for example, in the design of a station where a great number of conflicting uses occupy the same space.
Design drawings -
Design drawings are used to develop and communicate ideas about a developing design:
In the early stages (during the tender process) they might simply demonstrate to the client the ability of a particular design team to undertake the design. They may then be used to:
Develop and communicating the brief. - Investigate potential sites and assess options.
Investigate potential sites and assess options. - Develop the approved idea into a coherent and co-ordinated design.
Develop the approved idea into a coherent and co-ordinated design.
Communicate the developed design to other parties, such as the local planning authority, the building control body, contractors and suppliers.
Record the completed construction. - Record ongoing changes to the completed construction.
Record ongoing changes to the completed construction. - Some of these drawings are not traditionally considered to be design drawings, as either the design proper has not begun, or the design has effectively already been completed. However, almost all of them will include some element of investigation into, or development of the design, or they would serve no purpose.
Some of these drawings are not traditionally considered to be design drawings, as either the design proper has not begun, or the design has effectively already been completed. However, almost all of them will include some element of investigation into, or development of the design, or they would serve no purpose.
Very broadly, design drawings are categorised as:
Feasibility studies. - Options appraisals.
Options appraisals. - Concept drawings. Some designers will differentiate between 'concept design' and 'scheme design'. In this case, the 'concept' is the initial design idea, whereas the 'scheme' develops the concept, taking on board more functional and practical considerations.
Concept drawings. Some designers will differentiate between 'concept design' and 'scheme design'. In this case, the 'concept' is the initial design idea, whereas the 'scheme' develops the concept, taking on board more functional and practical considerations.
Detailed design (or developed design). - Technical design.
Technical design. - Tender drawings.
Tender drawings. - Shop drawings, installation drawings and construction drawings.
Shop drawings, installation drawings and construction drawings.
Design drawings will develop in detail from block and massing drawings and sketches to very detailed technical drawings describing every component in a way that will enable them to be constructed and operated.
When developing design drawings, it is important to consider what their purpose is, what information they are intended to convey and who they are intended to convey it to. This will determine their format, content, size, scale, and so on. For example, design drawings prepared for an inexperienced client may need to be very clear and to present only necessary information, at a scale and format that the client can easily view and share. Drawings for suppliers, on the other hand, may need to be very detailed and in a format that can be used for fabrication.
Design drawings may be prepared by a number of different practitioners, such as; architects, technicians and technologists, structural engineers, civil engineers, building services engineers, interior designers, landscape designers, contractors, subcontractors, suppliers, and so on. Some elements may first be designed by one individual or organisation and then taken on and developed by another.
It is important therefore that they are carefully integrated and co-ordinated to ensure that all elements are designed to an appropriate level of detail at the right time, and that designs prepared by different members of the project team create a single, unified set of information that can be constructed without clashes between components.
Typically, a lead designer will be appointed whose role includes integrating different aspects of the design and their interfaces into the overall design. Amongst other things, this may involve:
Ensuring collaborative practices are adopted. - Coordinating quality control systems.
Coordinating quality control systems. - Adopting standard methods and procedures.
Adopting standard methods and procedures. - Coordinating the preparation and issue of production information to contractors and suppliers.
Coordinating the preparation and issue of production information to contractors and suppliers.
Reviewing designs prepared by contractors and suppliers. - Different parts of the design team may also have design managers with an enabling and co-ordinating role.
Different parts of the design team may also have design managers with an enabling and co-ordinating role.
The preparation of design drawings has been revolutionised by the emergence first of computer aided design (CAD) and then building information modelling (BIM). BIM allows the whole project team to collaborate on the development of a single integrated information model (although at level 2, this model is a federated combination of separate models). However, the principle is the same as for traditional design in that the model will begin by communicating design intent, and will develop to become a virtual construction model.
In the early stages, it is likely to include massing diagrams or 2D symbols to represent generic elements of the design, with some critical elements developed in more detail. As the design progresses, the model will develop and the level of detail will increase, including, first, objects based on generic representations, and then specific objects with specifications and method statements attached along with information about space allocation for operation, access, maintenance, installation, replacement, and so on. Ultimately, it will contain all the information necessary to allow the objects in the model to be manufactured, installed or constructed and then operated.
Where BIM differs from traditional drawings is that a great deal of effort is put into defining the level of detail that is required for each element of the design at each stage of its development.
See also Types of drawings for building design for a description of different drawing formats and projections.
An occupier, or occupant, is a person/persons or organisation who lives in or uses property and/or land, either legally as the owner or tenant, or illegally as a squatter. The degree of occupational control over property or land is the most applicable test for who the occupier is. Tenants and licensees are considered the occupiers of the property in which they live, work or operate a business. The status of occupier is usually shared between a licensee and the owner.
Owners of property which has been let to tenants are considered to be the occupiers of areas over which they still have full control, i.e. the common staircase or landing in a flat. The landlord may often be responsible for carrying out repairs and maintenance as part of their duty as occupier.
If they exercise sufficient control over property, contractors working on site may also be considered to be occupiers.
The Occupiers Liability Act 1957 covers the liability of the occupier to visitors defined as being persons to whom the occupier gives an invitation or permission (express or implied) to enter or use the premises. A visitor will become a trespasser and so not fall under the liability of the occupier if they exceed the permission of the occupier. There is a duty of care placed upon the occupier by the Act, which states that reasonable care must be taken to ensure the safety of the visitor, similar to the common law standard of care relating to negligence.
The Occupiers Liability Act 1984 covers the liability of the occupier to people other than visitors, i.e. trespassers. While it is much narrower, the Act stipulates the scope of duty that an occupier has to ensure the safety of a trespasser; for example, where the occupier knows about risks relating to the premises; where the occupier knows that the trespasser is in the vicinity of those risks; or where the risk is such that the occupier is expected to have offered some form of protection.
Squatting is knowingly entering a residential building as a trespasser and living there, or intending to live there. (Ref. Gov.uk Squatting and the law.)
Since September 1st 2012 squatting in residential premises is a criminal offence, punishable by a prison sentence of up to 6 months or a fine of up to 5,000. This is as a result of S 144 of the Legal Aid, Sentencing and Punishment of Offenders Act 2012 coming into force.
Some people consider this to be a long-overdue reform that will help end the serious problem of squatters occupying residential premises. However it does not address a similar problem in commercial premises and may, indeed, lead to more squatting taking place in such premises.
S 144 provides that a person commits an offence if:
The person is in a residential building as a trespasser, having gained access as a trespasser.
The person knows, or ought to know, that they are a trespasser.
The person is living in the building or intends to do so.
A building is residential if it is '...designed or adapted, before the time of entry, for use as a place to live'. This is an important definition as it means that an offence will not be committed if such adaptation takes place AFTER the time of entry.
This means that commercial premises will be outside of the new offence, and commercial premises owners will not be able to rely upon this new legislation if faced with squatters in their premises. They will therefore have to continue to rely upon existing civil procedures to evict squatters unless they commit a criminal offence, such as:
Causing damage when entering the property. - Causing damage while in the property.
Causing damage while in the property. - Not leaving when theyre told to by a court.
Not leaving when theyre told to by a court.
Stealing from the property. - Using utilities like electricity or gas without permission.
Using utilities like electricity or gas without permission.
Fly-tipping. - Not obeying a noise abatement notice.
Not obeying a noise abatement notice. - (Ref. Government, Squatting in non-residential properties.)
(Ref. Government, Squatting in non-residential properties.)
Under rare circumstances, squatters may be able to acquire legal title to land on which the are squatting. See Adverse possession for more information.
In its broadest sense, the term faade can refer to any predominantly vertical face of a building envelope, such as an external wall. Consequently, a building may have more than one faade, such as the north faade, south faade and so on. Terraced buildings may only have two faades, a front faade and a rear faade.
Sometimes the term faade is used to refer more specifically to external faces of buildings that have particular architectural emphasis, such as an imposing design, decoration, the main entrance to the building and so on. This will typically be the front of the building, facing onto a street or other public open space, but it may also be other faces depending on their architectural treatment and importance.
The word faade is thought to be derived from the Latin 'facia', via the French faade meaning face or frontage. It was first used in English to refer to the front, or face of a building, but it has subsequently taken on an additional meaning in relation to concealing something behind a deceptive appearance, such as a person hiding their true feelings.
Considerations that might influence the design of a faade include:
Site, topography and climate. - The relationship to the street and access routes.
The relationship to the street and access routes.
The requirement for entrances, windows and other openings.
Stylistic preferences. - Requirements for climatic modification.
Requirements for climatic modification. - The need for security and privacy.
The need for security and privacy. - Available skills and materials.
Available skills and materials. - Regulations.
Regulations. - Context and planning restrictions.
Context and planning restrictions. -
opography - Topography refers to: The arrangement of the natural and artificial physical features (OED). Likely to strongly influence the location and characteristics of built form, drainage, movement and routes, and green infrastructure.
Topography refers to: The arrangement of the natural and artificial physical features (OED). Likely to strongly influence the location and characteristics of built form, drainage, movement and routes, and green infrastructure.
Ref Landscape Institute Technical Information Note TIN 05/2017, Townscape Character Assessment. https://landscapewpstorage01.blob.core.windows.net/www-landscapeinstitute-org/2018/04/tin-05-2017-townscape.pdf
Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines atmospheric pressure as: The air pressure at any given time for a specific location, which varies according to latitude and global weather patterns.
History - A cavity wall is a wall formed by an inner skin and an outer skin of masonry (sometimes referred to as leaves or wythes if they are a single unit wide), connected by ties, but separated by a cavity. The masonry is formed by units such as brick, stone or block. Very generally, if the external walls of a building are less than 30 cm thick, then they are unlikely to include a cavity.
A cavity wall is a wall formed by an inner skin and an outer skin of masonry (sometimes referred to as leaves or wythes if they are a single unit wide), connected by ties, but separated by a cavity. The masonry is formed by units such as brick, stone or block. Very generally, if the external walls of a building are less than 30 cm thick, then they are unlikely to include a cavity.
Cavity walls existed in Greek and Roman times, but only developed as a component of more recent construction in the 18th and 19th centuries. Even during this time, they were very rare, and generally involved two skins of masonry bonded by headers spanning across the cavity. The use of metal ties to connect the two skins only emerged in the second half of the 19th century and then became more common towards the beginning of the 20th century.
In the UK, most new, external masonry walls have been cavity walls since the 1920s.
Cavity wall.jpg -
Penetrating damp - The inclusion of a cavity in the construction of an external wall prevents moisture transmitting from the outer skin to the inner skin. Any moisture that reaches the cavity from the outside, runs down the internal surface of the external skin and is directed to weep holes in the outer skin by cavity trays, where it will drain to the outside.
The inclusion of a cavity in the construction of an external wall prevents moisture transmitting from the outer skin to the inner skin. Any moisture that reaches the cavity from the outside, runs down the internal surface of the external skin and is directed to weep holes in the outer skin by cavity trays, where it will drain to the outside.
Cavity trays are included where there are penetrations across the cavity, such as:
At an abutment with a roof. - Above openings such as doors and windows.
Above openings such as doors and windows. - Where extensions are constructed against existing walls.
Where extensions are constructed against existing walls. - Above concrete slabs or beams.
Above concrete slabs or beams. - Above airbricks, ducts and pipes.
Above airbricks, ducts and pipes. - At the bottom of a wall, if the cavity does not extend 225 mm below the damp-proof course.
At the bottom of a wall, if the cavity does not extend 225 mm below the damp-proof course.
Cavity tray.jpg -
Cavities are ventilated to ensure that any accumulating moisture is able to evaporate and vent to the outside.
Insulation - Cavities can also provide a space for the installation of thermal insulation, and as the requirement to reduce the passage of heat between the inside and outside of buildings has increased, so the width of cavities has also tended to increase.
Cavities can also provide a space for the installation of thermal insulation, and as the requirement to reduce the passage of heat between the inside and outside of buildings has increased, so the width of cavities has also tended to increase.
This means that older buildings tend to transfer more heat between the inside and outside and so can be colder in the winter, hotter in the summer, can suffer condensation, can be expensive to run, are high emitters of carbon and may not provide very good levels of thermal comfort.
Typically the U-values (a measure thermal conductance) of walls are:
Solid brick wall 2.0 W/m2K. - Cavity wall with no insulation 1.5 W/m2K.
Cavity wall with no insulation 1.5 W/m2K.
Insulated cavity wall 0.3 W/m2K or less.
The approved documents to the building regulations set limiting fabric standards for the elements of buildings. These are area-weighted averages that those elements may not fall below, and generally, to comply with the building regulations, fabric performance will need to be significantly better than these limits. The limiting U-value for walls in new dwellings is 0.3 W/m2K and for buildings other than dwellings is 0.35 W/m2K. Where new thermal elements are constructed, such as in a new extension, they should be at least 0.28 W/m2K.
Insulation is generally fixed to the external face of the internal skin of the cavity wall. This allows the remainder of the cavity to be ventilated without significant heat loss. However, in some cases, particularly where insulation is retrofitted, the entire cavity is filled. Great care must be taken in this case to ensure that a path is not created for the penetration of moisture between the outside and inside.
Cavity wall insulation.jpg -
The exact dimensions required to satisfy Part L of the building regulations will depend on the type of building and the thermal conductivity of the materials selected. Typically, with the correct selection of materials, a 102.5 mm external skin, 100 mm cavity (either filled or part-filled) and 100 mm internal skin, plastered on its internal face can be made to comply with part L.
Cavity walls that are not insulated can have insulation retrofitted by drilling small holes at regular intervals in the external skin and then blowing or injecting insulation into the cavity from the outside. Typically, water-repellent insulation is used such as expanded polystyrene (EPS) beads combined with a binding agent, or urea formaldehyde (UF) foam insulation. The drilled holes are then filled to match the existing finish. See Cavity wall insulation for more information.
Vapour barrier - As warm, moist internal air permeates through the structure of the wall towards the outside, it will tend to cool. When it reaches its dew point temperature, moisture will begin to condense as water. If this happens within the structure of the wall, this is known as interstitial condensation, and if this occurs within the inner skin of the wall, this can cause problems such as:
As warm, moist internal air permeates through the structure of the wall towards the outside, it will tend to cool. When it reaches its dew point temperature, moisture will begin to condense as water. If this happens within the structure of the wall, this is known as interstitial condensation, and if this occurs within the inner skin of the wall, this can cause problems such as:
Mould growth, migration of salts, mildew and staining.
Corrosion and decay of the building fabric. - Frost damage.
Frost damage. - Poor performance of insulation.
Poor performance of insulation. - To prevent this, Vapour Control Layers (VCL) or vapour barriers are positioned on the warm side of the cavity insulation, (i.e. between the insulation and the inner masonry skin), preventing the warm moist air from penetrating to a point where it might reach its dew point temperature.
To prevent this, Vapour Control Layers (VCL) or vapour barriers are positioned on the warm side of the cavity insulation, (i.e. between the insulation and the inner masonry skin), preventing the warm moist air from penetrating to a point where it might reach its dew point temperature.
The thermal resistance of a material is a measure of how resistant it is to the transfer of heat across it. The thermal resistance of a material is measured by its R-value. The higher the R-value of a material, the more effective it is as an insulator.
For more information, see R-value. -
Thermal resistance is the temperature difference between two defined material surfaces that induces a unit heat flow rate through a unit area. It is often described as the reciprocal of thermal transmittance, and can be derived from the thermal conductivity and the thickness of the materials.
R-values can be calculated by dividing the thickness of a material (in metres) by its thermal conductivity (k-value or lambda value () in W/mK). R-values are therefore expressed in m2K/W (or ft2Fhr/Btu in the USA). The overall R-value of a multi-layered element can be calculated by adding the R-values of its component materials.
R-values are not directly relatable to U-values however, as unlike U-values, R-values do not include surface heat transfers at the boundary of the element by convection and radiation, they are only a measure of the thermal resistance of the materials themselves.
The word insulate means to protect something by interposing a material between it and other elements that prevents transmission between them. The word insulation refers to the material that is interposed.
Insulation may be used in the construction industry for a number of different purposes:
Thermal insulation to prevent the transmission of heat, typically between the inside and outside of a building. For more information see: Thermal insulation.
Acoustic insulation to prevent the transmission of sound, for example between a recording studio and a performance space. For more information see: Acoustic insulation.
Fire insulation to prevent the passage of fire between spaces or components.
Electrical insulation to contain and separate electrical conductors.
Asset management - Facilities management is the ...integration of processes within an organisation to maintain and develop the agreed services which support and improve the effectiveness of its primary activities. Ref EN15221-1: 2006 Facility Management Part 1: Terms and definitions. It is concerned with the management of facilities at both a strategic and a day-to day level to deliver operational objectives and to maintain a safe and efficient environment.
Facilities management is the ...integration of processes within an organisation to maintain and develop the agreed services which support and improve the effectiveness of its primary activities. Ref EN15221-1: 2006 Facility Management Part 1: Terms and definitions. It is concerned with the management of facilities at both a strategic and a day-to day level to deliver operational objectives and to maintain a safe and efficient environment.
Asset management is'...The process of developing, operating, maintaining, upgrading and disposing of an asset using the most efficient and effective means.' Ref RIBA Plan of Work 2020.
The RIBA Plan of Work 2020 suggests that: 'Asset Management provides a further overlay to Facilities Management, formalising the maintenance regimes for the building. To achieve this, some of the components of the Building Systems, such as doors and items of plant, are given asset tags and unique identifiers, allowing maintenance planning to be optimised. Examples of asset management in practice include identifying when smoke seals on doors need to be inspected or when the batteries in escape signage need to be replaced, as well as recording when the requisite work was undertaken.'
Construction waste -
Construction activities can generate large amounts of waste materials that then need to be disposed of. In addition, at the end of a building's life, it may be deconstructed or demolished, generating significant amounts of waste. Construction waste includes waste that is generated during construction activities (such as packaging, or the products of demolition) and materials that are surplus to requirements (as a result of over-ordering or inaccurate estimating).
Typical construction waste products can include: -
Insulation and asbestos materials. - Concrete, bricks, tiles and ceramics.
Concrete, bricks, tiles and ceramics. - Wood, glass and plastic.
Wood, glass and plastic. - Bituminous mixtures, coal tar and tar.
Bituminous mixtures, coal tar and tar. - Metallic waste (including cables and pipes).
Metallic waste (including cables and pipes).
Soil, contaminated soil, stones and dredging spoil.
Gypsum. - Cement.
Cement. - Paints and varnishes.
Paints and varnishes. - Adhesives and sealants.
Adhesives and sealants. - Increasingly, there are options available in terms of reusing and recycling materials, and reducing the amount of waste produced in the first place, but despite this, a large amount of construction waste is still disposed of in landfill. 32% of landfill waste comes from the construction and demolition of buildings and 13% of products delivered to construction sites are sent directly to landfill without having being used (ref. Technology Strategy Board)
Increasingly, there are options available in terms of reusing and recycling materials, and reducing the amount of waste produced in the first place, but despite this, a large amount of construction waste is still disposed of in landfill. 32% of landfill waste comes from the construction and demolition of buildings and 13% of products delivered to construction sites are sent directly to landfill without having being used (ref. Technology Strategy Board)
This can be an expensive process, as the 1996 Finance Act introduced a tax on waste disposal on all landfill sites registered in the UK. For more information see: Landfill tax.
To help tackle this, a site waste management plan (SWMP) can be prepared before construction begins, describing how materials will be managed efficiently and disposed of legally during the construction of the works, and explaining how the re-use and recycling of materials will be maximised. For more information, see Site waste management plan.
It may be possible to eliminate a certain amount of construction waste through careful planning. For example, steel formwork systems might be capable of being used for concrete works which can then be reused elsewhere on the project/s in place of timber formwork which is classed as waste once it has been used.
Other types of construction waste may be capable of being minimised; for example, products which are provided with reduced packaging or those which are composed of recycled materials. There can also be opportunities to re-use materials and products which are in a suitable condition (e.g. doors, windows, roof tiles and so on), or exchange them for other materials with a different construction site.
Materials and products which cannot be eliminated, minimised or reused may have to be disposed of as waste. Before sending waste for disposal, it should be sorted and classified to allow waste contractors to manage it effectively and ensure that hazardous waste is properly handled.
For more information, see Construction waste disposal.
NB Inert waste is defined in Article 2(e) of the EU Landfill Directive (1999/31/EC) as waste that does not undergo significant physical, chemical or biological transformations.
Diverted waste is: 'All items removed from the project that are then recycled, reused, salvaged, composted, or otherwise diverted from landfills or incineration.' Ref The Living Building Challenge 4.0, A Visionary Path to a Regenerative Future, published by the International Living Future Institute in June 2019.
Finishes are used in the final part of the construction or manufacturing process, forming the final surface of an element. They can protect the element they finish from impact, water, frost, corrosion, abrasion, and so on, and/or they can be decorative.
Finishes commonly relate to internal surfaces, but they may also be applied to external elements. They can be applied wet or dry. Some elements are self-finished, that is the final surface is part of the material the element is formed from.
The application of finishes may involve the build up of more than one layer, which, whilst some of the layers will form the final exposed surface, they are nonetheless considered to be finishes. For example, an undercoat or primer might be applied to a wall before the final paint.
NBS categorise finishes as: -
Calcium sulfate based levelling screeds. - Cement based levelling / wearing screeds.
Cement based levelling / wearing screeds. - Decorative papers / fabrics.
Decorative papers / fabrics. - Edge fixed carpeting.
Edge fixed carpeting. - Insulation with rendered finish.
Insulation with rendered finish. - Intumescent coatings for fire protection of steelwork.
Intumescent coatings for fire protection of steelwork. - Mastic asphalt flooring/ floor underlays.
Mastic asphalt flooring/ floor underlays. - Metal lathing / anchored mesh reinforcement for plastered/ rendered coatings.
Metal lathing / anchored mesh reinforcement for plastered/ rendered coatings.
Painting / clear finishing. - Plastered / rendered / roughcast coatings.
Plastered / rendered / roughcast coatings. - Resin flooring.
Resin flooring. - Rubber / plastics / cork/ lino / carpet tiling / sheeting.
Rubber / plastics / cork/ lino / carpet tiling / sheeting.
Sprayed monolithic coatings. - Stone / concrete / quarry / ceramic tiling / mosaic.
Stone / concrete / quarry / ceramic tiling / mosaic.
Terrazzo tiling / in situ terrazzo. - Wood block / composition block / mosaic parquet flooring.
Wood block / composition block / mosaic parquet flooring.
However, this is some overlap in this categorisation with other building components, and some classifications might place some of these items within other categories. For example, plaster might be considered a lining rather than a finish stone might be considered part of the wall or floor construction, and so on.
Uniclass lists the following decorative coatings: -
Aluminium paints. - Casein paints.
Casein paints. - Cement paints.
Cement paints. - Concrete finishing coats.
Concrete finishing coats. - Concrete flash coats.
Concrete flash coats. - Concrete floor dyes.
Concrete floor dyes. - Concrete floor paints.
Concrete floor paints. - Concrete stains.
Concrete stains. - Distemper.
Distemper. - High pigment water-borne paint.
High pigment water-borne paint. - Limewashes.
Limewashes. - Micaceous iron oxide paints.
Micaceous iron oxide paints. - Multi-colour coatings.
Multi-colour coatings. - Multi-colour finish spatter coatings.
Multi-colour finish spatter coatings. - Oil-bound distempers.
Oil-bound distempers. - Plant oil paints.
Plant oil paints. - Plastic texture paints.
Plastic texture paints. - Resin-based breathable masonry paints.
Resin-based breathable masonry paints. - Semi-transparent timber stains and dyes.
Semi-transparent timber stains and dyes. - Silicate-based masonry coatings.
Silicate-based masonry coatings. - Solvent-based finishing coats.
Solvent-based finishing coats. - Solvent-borne gloss finishes.
Solvent-borne gloss finishes. - Solvent-borne masonry paints.
Solvent-borne masonry paints. - Solvent-borne matt and flat finishes.
Solvent-borne matt and flat finishes. - Solvent-borne mid-sheen finishes.
Solvent-borne mid-sheen finishes. - Tallow lime washes.
Tallow lime washes. - Water-borne gloss finishes.
Water-borne gloss finishes. - Water-borne masonry paints.
Water-borne masonry paints. - Water-borne matt and flat finishes.
Water-borne matt and flat finishes. - Water-borne mid-sheen finishes.
Water-borne mid-sheen finishes. - The choice of finishes might be influenced by factors, such as:
The choice of finishes might be influenced by factors, such as:
Colour and appearance (matt, gloss, silk, and so on).
Texture. - Maintenance and cleaning requirements.
Maintenance and cleaning requirements. - Durability.
Durability. - Expected life.
Expected life. - Weather resistance.
Weather resistance. - Corrosion resistance.
Corrosion resistance. - Availability.
Availability. - Preparation required.
Preparation required. - Ease of application.
Ease of application. - Drying time.
Drying time. - Cost.
Cost. - Safety or environmental issues.
Safety or environmental issues. - Waste.
Waste. - NB The word 'finish' may also refer to the completion of an activity.
NB The word 'finish' may also refer to the completion of an activity.
Information management is crucial in facilitating the smooth running of construction projects. It is the collecting, storing, distributing, archiving and deleting/destroying of information. Efficient information management ensures that the right people have the right information at the right time enabling them to make the right decisions. It is generally centrally managed and allows the parties to project or programme to manage their time and resources in the most effective way to achieve the desired results.
Typically, information management is achieved with the use of information management systems that provide a common structure, protocols and automated systems.
In the course of a construction project, consultants, clients, contractors and subcontractors generate huge amounts of information, much of it in a digital format. Storing information in this format is easier compared to hard copy documents, papers, drawings, letters, invoices and other by-products of the construction process (for more information see: Document control).
The introduction of Building Information Modelling (BIM) in the construction industry has helped standardise the way that digital data and information are created, stored and managed so that it is easier for teams to collaborate and ensure the client's information requirements are satisfied.
Once stored effectively, information can increase value by allowing management, planning, organising, structuring, processing, controlling, evaluating and reporting to take place in a more efficient way. However, the information that is stored must be retrievable and understandable if it is to have maximum value.
The first step in information management is creating or collecting information such as capturing the clients requirements, expressing the brief, formulating initial responses and solutions. This may be followed by architectural concept sketches, formal plans, which are then supplemented by designs from other consultants, such as engineers, surveyors, contractors and sub-contractors. Depending on requirements, some stakeholders may also have rights to access or input information.
On projects using BIM, these requirements may be described as Employer's Information Requirements (EIR). A common data environment (CDE) may be created as the single source of information. This is used to collect, manage and disseminate documentation, the graphical model and non-graphical data for the whole project team (i.e. all project information whether created in a BIM environment or in a conventional data format). On small projects, the CDE may simply be a collection of folders on a single server or could be a web-based file-sharing application such as Dropbox.
For more information see: Building information modelling.
Projects may go through a number of stages, or gateways, at which information is collated and approved, then change control processes are introduced for aspects of that information that are considered 'frozen'. For more information see: Change control and Data drop.
A Request for Information (RFI) (occasionally referred to as a Technical Query) is a formal question asked by one party to a contract on a construction project to the other party. Typically this will be a request from the contractor to the clients consultant team, but it may be between any of the parties, for example from a sub-contractor to a contractor. For more information see: Request for Information
In construction, a fabrication is an item that is manufactured by a fabricator for installation on a building site as part of an ongoing construction project, for example, a window, door, steel member, staircase and so on that is typically made off-site to the specification required for the project.
A buildings windows are normally fabricated off-site to special dimensions that the fabricator has either taken off the drawings or specification, or else has visited the site and measured for the item to be supplied. The fabricator can then proceed to manufacture. It should be noted that a fabrication can be termed prefabricated if it is made off site. Delivered to site ready to install means that these items can help reduce waste and time and cut emissions.
For more information see: Prefabrication. -
In theory, it is possible for fabrications to be made on site (or in a flying factory) as opposed to off site, assuming the process is simple enough (e.g timber windows) and there is enough space on site to allow the fabrication process to take place. In most circumstances however, fabricating building elements can require complex machinery that requires the controlled conditions, accuracy and space offered by a manufacturing plant.
Introduction - The term 'glazing' refers to the glass component of building's faade or internal surfaces. Historically, the installation of glazing was generally undertaken by a specialist glazier, but today it is possible to purchase an entire window which can be fitted by a general contractor. In older buildings, re-glazing can be done by specialist firms that restore rather than replace windows.
The term 'glazing' refers to the glass component of building's faade or internal surfaces. Historically, the installation of glazing was generally undertaken by a specialist glazier, but today it is possible to purchase an entire window which can be fitted by a general contractor. In older buildings, re-glazing can be done by specialist firms that restore rather than replace windows.
Whereas in the past windows were generally single glazed consisting of just a single layer of glass, today there are many different options for glazing. A substantial amount of heat is lost through the window, and so double glazed and triple glazed units have been developed as welled as secondary glazing to provide more insulation (as well as better acoustic performance) thereby improving the energy efficiency of a building and reducing carbon emissions.
For more information see: Double glazing and Triple glazing and Secondary glazing.
Glass can also be tinted to reject sunlight, coated in a translucent film to increase energy efficiency, or be self-cleaning. It is most common for glazing to be clear glass; however, there are also many varied forms of etched, textured, frosted, stained or tinted glass for privacy or aesthetic purposes. For more information, see Glass manifestation.
See also: Types of window. -
Insulated glass unit (IGU) - An insulated glass unit (IGU) combines multiple glass panes into a single unit system, for example a window. Double glazed units are made of two sheets of glass with a cavity between them that is generally 4-20 mm which creates an insulating barrier. Triple glazed units have three sheets of glass. IGUs help combat heat loss, making a building warmer, quieter and cheaper to run.These are prefabricated panels fitted into a single planar system.
An insulated glass unit (IGU) combines multiple glass panes into a single unit system, for example a window. Double glazed units are made of two sheets of glass with a cavity between them that is generally 4-20 mm which creates an insulating barrier. Triple glazed units have three sheets of glass. IGUs help combat heat loss, making a building warmer, quieter and cheaper to run.These are prefabricated panels fitted into a single planar system.
The sheets of glass are generally tempered (toughened) or laminated for safety. To keep the panes of glass apart, pane spacers are set around the inside edges. The more efficient windows use spacers that contain little-or-no metal, often known as 'warm edge' spacers.
The cavity between the panes can be a vacuum (the efficiency is dependent upon the quality of the sealing), or a heavy inert gas. This improves insulation and prevents condensation within the unit. Argon is the most commonly used gas, but Krypton or Xenon are more efficient and more expensive.
R-values are a measure of the thermal resistance of a material of a specific thickness, that is, its resistance to the transfer of heat across it. The higher the R-value of a material, the more effective it is as an insulator. Double-glazed units filled with air have an R-value of around R-2. Filling with Argon gas raises the value to R-3. Changing the glass to Low-E (see below), can raise the value to R-4. Triple glazed IGUs can have a value of R-5 or higher.
Types of glazing - There are many different types of glazing with different manufacturing processes, strength, energy efficiency, appearances and so on. The most common include:
There are many different types of glazing with different manufacturing processes, strength, energy efficiency, appearances and so on. The most common include:
Annealed glass - This is a piece of float glass that has been cooled in a slow and controlled manner. The internal stresses within the sheet of glass are reduced by this process making the resulting glass stronger and less likely to break than it would otherwise be. There can be safety concerns using annealed glass as it can break into large jagged shards.
This is a piece of float glass that has been cooled in a slow and controlled manner. The internal stresses within the sheet of glass are reduced by this process making the resulting glass stronger and less likely to break than it would otherwise be. There can be safety concerns using annealed glass as it can break into large jagged shards.
Float glass - This is named after the modern process used to create large, thin, flat panels from molten glass which is floated onto a pool of molten metal such as tin. This process produces a very smooth sheet of glass with a highly consistent thickness.
This is named after the modern process used to create large, thin, flat panels from molten glass which is floated onto a pool of molten metal such as tin. This process produces a very smooth sheet of glass with a highly consistent thickness.
Fully tempered glass - Tempering is the process by which annealed glass is heated in the same way as heat strengthened glass. The glass is cooled more rapidly which allows the internal portion of the glass to remain fluid for longer than the outer surfaces. This means that an equal amount of tensile and compressive stresses are formed across the glass which allows it to become in the order of four times as strong as annealed glass. This is used as a safety glass, as it shatters into small granular pieces rather than sharp shards, reducing the risk of injury.
Tempering is the process by which annealed glass is heated in the same way as heat strengthened glass. The glass is cooled more rapidly which allows the internal portion of the glass to remain fluid for longer than the outer surfaces. This means that an equal amount of tensile and compressive stresses are formed across the glass which allows it to become in the order of four times as strong as annealed glass. This is used as a safety glass, as it shatters into small granular pieces rather than sharp shards, reducing the risk of injury.
For more information see: Tempered glass. -
Heat soaked tempered glass - This is used as a means of testing glass panes that are to be used in safety critical situations, such as a glass railing. Tempered glass panes are heated to a temperature of around 550 degrees Fahrenheit for a few hours. This causes any unstable nickel sulfide inclusions (imperfections that may cause spontaneous breakage of the pane) to expand disproportionately to the glass, making the glass break.
This is used as a means of testing glass panes that are to be used in safety critical situations, such as a glass railing. Tempered glass panes are heated to a temperature of around 550 degrees Fahrenheit for a few hours. This causes any unstable nickel sulfide inclusions (imperfections that may cause spontaneous breakage of the pane) to expand disproportionately to the glass, making the glass break.
For more information see: Tempered glass. -
Heat-strengthened glass - This is made from a sheet of annealed glass reheated beyond its annealing point of around 1200 degrees Fahrenheit and then cooled slowly. Heat strengthened glass may be twice as strong as annealed glass, but may still need to be laminated for use in buildings.
This is made from a sheet of annealed glass reheated beyond its annealing point of around 1200 degrees Fahrenheit and then cooled slowly. Heat strengthened glass may be twice as strong as annealed glass, but may still need to be laminated for use in buildings.
Laminated glass - Laminated glass is used where glazing must remain intact if it is broken, either for safety or security reasons. It is made by fusing two or more layers of glass with inter-layers of polyvinyl butyral (PVB) through the use of heat and pressure. If it is made using heat strengthened glass, the pane will break into large pieces but will be held in the frame by the PVB inter-layer. If it is made from tempered glass, the sheet may fall out of the frame but will mostly stay together due to the inter-layer.
Laminated glass is used where glazing must remain intact if it is broken, either for safety or security reasons. It is made by fusing two or more layers of glass with inter-layers of polyvinyl butyral (PVB) through the use of heat and pressure. If it is made using heat strengthened glass, the pane will break into large pieces but will be held in the frame by the PVB inter-layer. If it is made from tempered glass, the sheet may fall out of the frame but will mostly stay together due to the inter-layer.
Low-emissivity (Low-E) glass - The term 'low-e glass' is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity so that it reflects, rather than absorbs, long-wave infra-red radiation.
The term 'low-e glass' is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity so that it reflects, rather than absorbs, long-wave infra-red radiation.
In cooler climates this means that long-wave infra-red radiation that builds up inside a building is reflected by the glass back into the space, rather than being absorbed by the glass and then partially re-radiated to the outside. This reduces heat loss and so the need for artificial heating.
In hotter climates, a low-e coating means that long-wave infra-red radiation outside the building is reflected back out of the building, rather than being absorbed by the glass and then partially re-radiated to the inside. This reduces the heat build-up inside the building and so the need for cooling. In hotter climates, a low-e coating might be used in conjunction with solar-control glass to reduce the amount of short-wave solar radiation entering the building.
The two main types of low-e coating are tin and silver. Tin oxide is applied to the glass at high temperatures to create a very hard and durable low-e coating. Silver coating must be enclosed within the glazing unit so that oxidation doesn't cause the degradation of the silver over time.
Patent glazing - The term patent glazing refers to a non-load bearing, two-edge support cladding system. Its name relates to the number of patents that were taken out in the 19th and 20th centuries for different versions of the system.
The term patent glazing refers to a non-load bearing, two-edge support cladding system. Its name relates to the number of patents that were taken out in the 19th and 20th centuries for different versions of the system.
For more information see: Patent glazing. -
Safety glass - The term safety glass refers to a range of glass types that have been strengthened or reinforced to make them less susceptible to breakage or shattering and to make them safer when they are broken. Safety glass should not splinter into large shards when broken. For more information see: Safety glass.
The term safety glass refers to a range of glass types that have been strengthened or reinforced to make them less susceptible to breakage or shattering and to make them safer when they are broken. Safety glass should not splinter into large shards when broken. For more information see: Safety glass.
Security glass - Security glass provides resistance to forced entry and manual attack. For more information see: Security glazing.
Security glass provides resistance to forced entry and manual attack. For more information see: Security glazing.
Self-cleaning glass - A transparent coating can be applied to glass during the manufacturing which reacts with the sun's UV rays to break down dirt and grime which forms on the outside of the windows, and when it rains, the decomposed dirt natural rinses away. The coating has hydrophilic properties which mean it attracts water over its entire surface, avoiding unsightly uneven water marks.
A transparent coating can be applied to glass during the manufacturing which reacts with the sun's UV rays to break down dirt and grime which forms on the outside of the windows, and when it rains, the decomposed dirt natural rinses away. The coating has hydrophilic properties which mean it attracts water over its entire surface, avoiding unsightly uneven water marks.
Stained glass - Stained glass is a type of glazing material that is coloured (stained), either by the addition of metallic salts during the manufacturing process, or by having colour applied to its surface and then being fired in a kiln to fuse the colour to the glass.
Stained glass is a type of glazing material that is coloured (stained), either by the addition of metallic salts during the manufacturing process, or by having colour applied to its surface and then being fired in a kiln to fuse the colour to the glass.
For more information see: Stained glass. -
Wired glass - This is most often used as a fire resistant glass because the wire holds the glass in place if high temperature causes it to break. The wire mesh is better at holding glass in place than the PVB films used in laminated glass.
This is most often used as a fire resistant glass because the wire holds the glass in place if high temperature causes it to break. The wire mesh is better at holding glass in place than the PVB films used in laminated glass.
Window Energy Ratings - The Window Energy Ratings (WER) is a scale developed by the British Fenestration Ratings Council (BFRC) to measure the thermal performance of windows. The BFRC label indicates the rating of the window on a scale running from A+ (the most energy efficient) to G (the least efficient).
The Window Energy Ratings (WER) is a scale developed by the British Fenestration Ratings Council (BFRC) to measure the thermal performance of windows. The BFRC label indicates the rating of the window on a scale running from A+ (the most energy efficient) to G (the least efficient).
The overall performance is dependent on the combined efficiency of the frame, the glazing and the air tightness of the finished windows. Low-e windows generally get the highest performing energy ratings. Professional installers should be registered with a Competent Person Scheme or register the installation through Local Authority Building Control. English and Welsh competent person schemes are:
Fenestration Self-Assessment Scheme (FENSA): They guarantee that its installers and frames comply with building regulations.
British Standards Institution (BSI). - Certass Glazing Scheme: They also register and approve installers.
Certass Glazing Scheme: They also register and approve installers.
Building regulations - Under the building regulations in England and Wales, new and replacement windows must meet certain energy efficiency requirements, as well as other requirements relating to safety, means of escape and ventilation.
Under the building regulations in England and Wales, new and replacement windows must meet certain energy efficiency requirements, as well as other requirements relating to safety, means of escape and ventilation.
Approved Document L classifies an external window as a 'controlled fitting', which refers to the whole unit including the frame. New and replacement windows in existing homes in England, Wales and Scotland must be at least WER band C or have a U-value of 1.6. However, the regulations state that:
'Replacing the glazing whilst retaining an existing frame is not providing a controlled fitting, and so such work is not notifiable and does not have to meet the Part L standards, although where practical it would be sensible to do so.'
Part K of the Building Regulations require that where 'building work' is carried out in a critical location involving glass, that safety glazing is used. Safety glazing is required:
In any glazed area within a window below 800 mm from floor level.
In any glazed area within a window that is 300 mm or less from a door and up to 1500 mm from floor level.
Within any glazed door up to 1500 mm from floor level.
Fabric structures are tensile structures in which a membrane is 'stretched' to form a three-dimensional surface that can be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some other materials.
Typically, the membrane is formed by a structural fabric, consisting of a woven base cloth, coated on both sides, and held in position by tension forces imposed by a structural framework or a cabling system. Unlike conventional roofing systems, fabric structures can cover very large areas with no supporting columns. This makes them particularly suitable for buildings such as sports faculties, auditoriums, shopping centres, transport interchanges, and so on.
They can be relatively quick to construct and can be relocatable, making them suitable for temporary uses, and so have historically be associated with structures such as circus tents, or with military uses.
History - The origins of fabric structures can be traced back more than 44,000 years to the ice age and the Siberian Steppe, where remains have been found of simple shelters constructed from animal skins draped between sticks. Fabric structures developed and thrived predominately in regions where materials were scarce, or where survival required mobility; both conditions which tend to be brought about by low rainfall.
The origins of fabric structures can be traced back more than 44,000 years to the ice age and the Siberian Steppe, where remains have been found of simple shelters constructed from animal skins draped between sticks. Fabric structures developed and thrived predominately in regions where materials were scarce, or where survival required mobility; both conditions which tend to be brought about by low rainfall.
From these purely functional origins however, the tent evolved over many centuries to become a symbol of frivolity. Fabric structures became almost entirely recreational, and other than for military purposes were used in ways which ran entirely contrary to their functional origins.
This was to change during the nineteenth and twentieth centuries as architects became inspired by technological breakthroughs in structural engineering and architectural theorising on an emerging functional aesthetic.
The architect, Frei Otto, began exhaustive investigations into the structural principles behind a new generation of fabric buildings, and ultimately, this led to the extraordinary developments we now associate with modern fabric structures such as the roof of the Hajj Terminal at Jeddah Airport, the Millennium Dome and Denver International Airport.
Materials - The earliest fabrics were formed by simple membranes extracted from animals or vegetables. Later these membranes were cut into strips and interlaced to form larger, more practical textiles, and eventually these strips were twisted into circular sections allowing the manufacture of flexible, continuos fibres with enhanced strength.
The earliest fabrics were formed by simple membranes extracted from animals or vegetables. Later these membranes were cut into strips and interlaced to form larger, more practical textiles, and eventually these strips were twisted into circular sections allowing the manufacture of flexible, continuos fibres with enhanced strength.
Cotton was the first material to possess any significant structural strength but modern fabric structures tend to be formed using PVC coated polyester or PTFE coated glass.
Topcoats of protective fluorinated polymer lacquers (PVDF) applied to PVC coated polyester enhance its 'cleanability' and provide additional protection. In average climates, this fabric can last 15-20 years, or around 5 years less in sites where there is high exposure to sunlight.
Architectural fabric.jpg -
PFTE-coated glass cloth is more expensive, but is strong and durable, and can have a lifespan of 30 to 50 years. It also has the advantage of being low maintenance and self-cleaning.
More recently, high performance materials such as silicone coated glass, woven PTFE fibre, ETFE foil, laminated open weave grids and insulated and phase change materials have been developed, however, PVC coated polyester and PTFE coated glass remain the industry standards.
These tensile fabrics, (sometimes referred to as structural membranes or architectural fabrics) are available in a wide range of thicknesses, strengths, colours and translucencies.
For more information see: The development of structural membranes and Architectural fabrics.
Properties and characteristics - Fabric structure.JPG
Fabric structure.JPG -
Fabric structures are generally given their structural stability by double curvature. This may be:
Anticlastic (saddle shaped), where the two axes of the fabric curve in opposite directions.
Synclastic (dome shaped), where the two axis of the fabric curve in the same direction.
Anticlastic shapes tend to be formed by cables at the perimeter of fabric panels pulling them into tension, whilst synclastic shapes tend to be formed by internal air pressure (similar to blowing up a balloon, but at a very low pressure not noticeable to occupants).
Whilst the fabric itself may be very thin (perhaps just 1 mm), the tensile force imposed on it to ensure it remains stable under load can be high, and so the supporting structure required can be significant to transfer loads to the foundations.
The non-linear, dynamic behaviour of architectural fabrics can be modelled using specialist form-finding software. This allows designers to vary the elements, boundary conditions and geometry of the design and rapidly determine the most efficient structural solution. This software can also be used to generate cutting patterns for automatically cutting the fabric panels to create the form required. For more information see: The structural behaviour of architectural fabric structures.
In very general terms, space is an abstract term which tends to refer to a location which has not had a specific human value or purpose attached to it. This is as opposed to a place which has an identifiable character, or a location which has geometrical certainty.
Designers sometimes refer to 'negative space' as the space between and around objects such as buildings.
A public space is an area that tends to be open and accessible to all people. This includes roads, pavements, town squares, parks, beaches, and to a more limited extent public buildings such as town halls and libraries. The term 'common land' is sometimes used to refer to land in public ownership or to which everyone has access. To have such status, land must be legally registered as a common.
Privately-owned 'public' spaces are also a common feature of urban developments.These are spaces that are open to the public but owned and maintained by a private company. In some cases, this has been criticised for removing space from the public realm, with owners sometimes applying more rules and restrictions than there would otherwise be. Those in favour however argue that, in many cases, it can involve the improvement and regeneration of spaces that were previously neglected or poorly-used.
Space can also refer to a specific area or volume within a building, such as; useable and un-useable space, storage space, teaching space, and so on.
There are a number of guidelines, standards and regulations for the sizes of specific spaces. For example, in 2015, the government published the Technical housing standards - nationally described space standard which replaced existing space standards used by local authorities. This standard deals with internal space within new dwellings and sets out requirements for the gross internal floor area of new dwellings at a defined level of occupancy as well as floor areas and dimensions for key parts of homes.
Floor area ratio - The floor area ratio (FAR), also known as the plot ratio, is a measure of the total permitted floor area of a building, in relation to the total area of the lot (or plot) on which the building stands:
The floor area ratio (FAR), also known as the plot ratio, is a measure of the total permitted floor area of a building, in relation to the total area of the lot (or plot) on which the building stands:
Gross floor area of all floors of the building / Area of the building lot = FAR
A higher ratio indicates a higher-density environment. -
The concept emerged in Europe in the 19th century, and was then taken up in the USA in the 20th century as a form of zoning control for rapidly developing cities. FAR is now often used by urban planners, particularly in the USA, for assessing, or restricting, planning permissions, setting a limit on the 'load factor' generated by new developments, beyond which undue stress is placed on a city and its infrastructure.
A low permitted FAR may deter development, whilst a higher FAR allows more usable area, and hence higher potential sales.
The same FAR value can be achieved by buildings with varying numbers of storeys. For example:
1,000 sq. m building with one storey / 4,000 sq. m lot = 0.25
500 sq. m building with two storeys / 4,000 sq. m lot = 0.25
An FAR of 1.0 allows the developer to build a one-storey building over the lot, or a two-storey building over half the lot, or a three-storey building over one-third of the lot, and so on.
An FAR of 2.0 allows the developer to build a two-storey building over the lot, or a four-storey building over half, and so on.
Bradford City Centre Design Guide, Supplementary Planning Document, published in 2006, defines plot ratio as: A measure of density for non-residential use. This is expressed as a ratio in which the first number relates to the floor area of the building and the second to the area of the site. A 2:1 ratio therefore denotes a building that has two times the floor area of the site. This could be a two storey building covering the entire site or a four storey building covering half of the site.
NB Land measurement for planning and development purposes, Guidance Note, Global 1st edition, Published by the Royal Institution of Chartered Surveyors (RICS) in May 2021, defines plot ratio (PR) as: the ratio of total development floor area to site area. Development floor area may be measured as gross external area (GEA) or gross internal area (GIA), but whichever is used or modifications of them should be clearly stated. Gross external area and gross internal area are defined in Property measurement, RICS professional statement. It suggests that floor area ratio (FAR) and floorspace ratio (FSR) are similar terms.
Net internal area NIA - The area of a building can be measured in a number of different ways:
The area of a building can be measured in a number of different ways:
Gross external area (GEA). - Gross internal area (GIA).
Gross internal area (GIA). - Net internal area (NIA).
Net internal area (NIA). - It is very important when describing the area of a building to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations, and so on.
It is very important when describing the area of a building to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations, and so on.
The net internal area (NIA) of a building is the usable area measured to the internal finish of the perimeter or party walls, ignoring skirting boards, at each floor level. Net internal area covers all of those areas that can be used for a particular purpose.
The UK governments Valuation Office Agency (VOA) Code of measuring practice: definitions for rating purposes suggests that Net Internal Area includes:
Kitchens. - Any built in cupboards or units that occupy usable areas.
Any built in cupboards or units that occupy usable areas.
Perimeter skirting boards, mouldings and trunking. - Open circulation areas such as atria, corridors and entrance halls.
Open circulation areas such as atria, corridors and entrance halls.
Partition walls and other dividing elements. - Net internal area excludes:
Net internal area excludes: -
Internal structural walls. - Walls (whether structural or not) enclosing excluded areas.
Walls (whether structural or not) enclosing excluded areas.
Piers, columns, chimney breasts, ducts and other projections.
Cleaners cupboards. - Lifts, lift rooms, lift wells.
Lifts, lift rooms, lift wells. - Stairwells and landings.
Stairwells and landings. - Stairwells, entrance halls, atria, landings and balconies used in common or for the purpose of essential access.
Stairwells, entrance halls, atria, landings and balconies used in common or for the purpose of essential access.
Corridors and other circulation areas used in common with other occupiers or of a permanent essential nature.
Boiler rooms, fuel stores, plant rooms and tank rooms other than those of a trade process nature.
Car parking areas. - Spaces occupied by cooling and heating equipment, air conditioning systems and ducting which renders the space substantially unusable.
Spaces occupied by cooling and heating equipment, air conditioning systems and ducting which renders the space substantially unusable.
Areas with a headroom of less than 1.5m.
Toilets and associated lobbies, unless additional toilets have been installed.
Areas under the control of service or other external authorities.
It suggests that, 'essential access' '...will not include reception areas or areas capable of use and situated within entrance halls, atria and landings etc.'
In relation to the term 'permanent essential nature' it suggests that, 'apart from areas used in common with other occupiers, corridors excluded from NIA are those of a permanent essential nature, i.e. internal corridors between structural walls (usually found in older buildings). Fire corridors and smoke lobbies which are defined by non-structural walls - but only where they are permanent and essential to any prospective tenant of the property and do not merely serve the needs of the actual occupier. If the latter, they should be included.'
RICS Guidance Note, A guide for Property Professionals, 6th Edition Code of measuring practice 2007, is in general agreement with the Valuation Office Agency definition, of net internal area.
The area of a building can be measured in a number of different ways:
Gross external area (GEA). - Gross internal area (GIA).
Gross internal area (GIA). - Net internal area (NIA).
Net internal area (NIA). - It is very important to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations and so on.
It is very important to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations and so on.
The UK governments Valuation Office Agency (VOA) Code of measuring practice: definitions for rating purposes suggests that gross external area refers to the whole area of a building taking each floor into account, including perimeter walls. This includes:
Perimeter wall thickness and external projections. - Areas occupied by internal walls (whether structural or not) and partitions.
Areas occupied by internal walls (whether structural or not) and partitions.
Columns, piers, chimney breasts, stairwells, lift wells, and so on.
Lift rooms, plant rooms, tank rooms, fuel stores, whether or not above roof level.
Open-sided covered areas (should be stated separately).
Gross external area excludes: -
Open balconies. - Open fire escapes.
Open fire escapes. - Open sided covered ways.
Open sided covered ways. - Open vehicle parking areas, terraces and so on.
Open vehicle parking areas, terraces and so on.
Minor canopies - Any area with a headroom of less than 1.5 m (except under stairways).
Any area with a headroom of less than 1.5 m (except under stairways).
Any area under the control of service or other external authorities
It suggests that party walls should be measured to their centre lines.
According to NRM1: Order of cost estimating and cost planning for capital building work, the gross external area is '...the area of a building measured externally (i.e. to the external face of the perimeter walls) at each floor level.The rules of measurement of gross external floor area are defined in the latest edition of the RICS Code of Measuring Practice.'
The VOA Code of measuring practice is in general agreement with RICS Guidance Note, A guide for Property Professionals, 6th Edition Code of measuring practice 2007, other than, areas with a headroom of less than 1.5m which are excluded from the VOA measurement.
Gross site area - For the purposes of determining housing density, gross site area is the total land area as part of the development. Infrastructure and services serving a wider area (such as parks and open space) are considered part of the gross site area. This includes:
For the purposes of determining housing density, gross site area is the total land area as part of the development. Infrastructure and services serving a wider area (such as parks and open space) are considered part of the gross site area. This includes:
Major distributor roads. - Primary schools, churches, shopping areas etc.
Primary schools, churches, shopping areas etc.
Open spaces serving the wider areas. - Significant landscape buffering strips.
Significant landscape buffering strips. - Net site area is the land that is available for development. It is also referred to as the area of developable land. The net site area is more than the land for dwellings and private space and includes other areas that contribute to the use and enjoyment directly linked to the developed dwellings. This includes:
Net site area is the land that is available for development. It is also referred to as the area of developable land. The net site area is more than the land for dwellings and private space and includes other areas that contribute to the use and enjoyment directly linked to the developed dwellings. This includes:
Access roads within the site. - Private garden space.
Private garden space. - Car parking space.
Car parking space. - Incidental open space.
Incidental open space. - Childrens play areas.
Childrens play areas. - In planning practice it is common to determine net site area as a percentage of gross site area, known as the gross to net ratio.
In planning practice it is common to determine net site area as a percentage of gross site area, known as the gross to net ratio.
Ref Telford & Wrekin Council Local Plan 2011 2031 Technical Paper. Density and net site area study, July 2015.
Escape - International Fire Safety Standards: Common Principles, Safe Buildings Save Lives, First Edition, published by the International Fire Safety Standards Coalition in 2020 defines escape as: The egress of occupants from a Building.
International Fire Safety Standards: Common Principles, Safe Buildings Save Lives, First Edition, published by the International Fire Safety Standards Coalition in 2020 defines escape as: The egress of occupants from a Building.
Combustion - The combustion process is: The chemical process of burning via a substance (fuel) reacting rapidly with oxygen and giving off heat. Ref Climate Emergency Design Guide: How new buildings can meet UK climate change, published by The London Energy Transformation Initiative (LETI) in January 2020.
The combustion process is: The chemical process of burning via a substance (fuel) reacting rapidly with oxygen and giving off heat. Ref Climate Emergency Design Guide: How new buildings can meet UK climate change, published by The London Energy Transformation Initiative (LETI) in January 2020.
A combustion appliance is an apparatus where fuel is burned to generate heat for space heating, water heating, cooking or other similar purpose. The appliance does not include systems to deliver fuel to it or for the distribution of heat. Typical combustion appliances are boilers, warm air heaters, water heaters, fires, stoves and cookers. Ref Approved document J, Combustion appliances and fuel storage systems.
The term combustion plant refers to any piece of equipment that involves the combustion of a fuel to generate energy. Ref The HS2 London-West Midlands Environmental Statement, published by the Department for Transport in November 2013.
The term combustibility refers to the tendency of a substance to burn as a result of fire or chemical reaction. It is can be expressed as a property that is a measure of how easily a substance will ignite or burn, an important consideration when materials are being used or stored for construction purposes.
Combustibility - The term combustibility refers to the tendency of a substance to burn as a result of fire or chemical reaction. It is can be expressed as a property that is a measure of how easily a substance will ignite or burn, an important consideration when materials are being used or stored for construction purposes.
The term combustibility refers to the tendency of a substance to burn as a result of fire or chemical reaction. It is can be expressed as a property that is a measure of how easily a substance will ignite or burn, an important consideration when materials are being used or stored for construction purposes.
The term flammable may be used to describe substances that ignite more easily, whilst substances that are harder to ignite or that burn less intensely may be referred to as combustible. For more information see: Flammable.
Less combustible materials may be described as 'materials of limited combustibility'. Approved document B of the building regulations defines limited combustibility as: 'a material performance specification that includes non-combustible materials, and for which the relevant test criteria are set out in Appendix A, paragraph 9.'
Approved document J, Combustion appliances and fuel storage systems defines non-combustible materials as:
the highest level of reaction to fire performance. Non-combustible materials include:
Any material which when tested to BS 476-11:1982 (2007) does not flame nor cause any rise in temperature on either the centre (specimen) or furnace thermocouples.
Products classified as non-combustible in tests following the procedures in BS 476-4:1970 (2007).
Any material classified as class A1 in accordance with BS EN 13501-1:2002 Fire classification of construction products and building elements. Classification using data from reaction to fire tests.
Following the Grenfell Tower Fire, a decision was taken to ban combustible materials in the cladding for buildings over 18m in height. The following change to approved document 7 came into force on 21 December 2018.
The Building Regulations restrict the use of combustible materials in the external walls of certain buildings over 18m in height. Refer to regulation 7(2) of the Building Regulations and to Approved Document B: volume 2, part B4 for details.
The issue was raised again in November 2019 following a fire at The Cube in Bolton. In this case HPL cladding was used, and the building was less than 18m in height, resulting in calls for the ban on combustible cladding materials to be extended. For more information see: The Cube.
On 27th November 2019, after a challenge to the consultation process that introduced the ban, the High Court ruled that the consultation had been inadequate in respect of the inclusion of products intended to reduce heat gain within a building (for example, blinds, shutters and awnings) within the ban. As a result the Court quashed one part of the 2018 regulations which had included within the ban a device for reducing heat gain within a building by deflecting sunlight which is attached to an external wall. The practical effect of the Court judgment is that the regulations now exist as if that section of the regulations had never been included in the ban. Ref https://www.gov.uk/government/publications/building-amendment-regulations-2018-circular-032019
In January 2020, the government launched a review of the ban on the use of combustible materials in the external walls of buildings over 18m that was introduced in 2018.
In terms of the built environment, the term interior refers to the internal space of a building or structure. Any part of a building or structure that physically separates an interior from the external environment may be referred to as an enclosure. For more information, see Principles of enclosure.
Building interiors are sometimes planned and designed by interior designers. Interior design is sometimes perceived to be a matter of interior decoration, but in fact, it is a complex subject that often involves working alongside other professionals, such as architects and engineers, as part of a larger project.
Components of interiors might include; furniture, fixtures, fittings, finishes, equipment, lighting, heating, ventilation, air conditioning and so on.
Interior design requires detailed knowledge of: -
Design styles. - Spatial design.
Spatial design. - How people are affected by their environments.
How people are affected by their environments. - Construction and materials.
Construction and materials. - Regulations and approvals.
Regulations and approvals. - Procurement and project management.
Procurement and project management. - Technical matters such as acoustics and lighting, and increasingly, technologies such as audio visual equipment and ITC.
Technical matters such as acoustics and lighting, and increasingly, technologies such as audio visual equipment and ITC.
Sustainability. - The role of other consultants.
The role of other consultants. - An important part of designing interiors is space planning. This is used to determine how a space (or spaces) should be laid out and used. This may be undertaken as part of the building design process, or as a stand-alone exercise looking at how best to plan an existing space, or a space that is being developed (for example, a tenant determining how to fit out their part of a new development). It can be used for very simple spaces such as hotel bedrooms, through to very complex industrial buildings. Good space planning can improve the wellbeing and productivity of the occupants of a space.
An important part of designing interiors is space planning. This is used to determine how a space (or spaces) should be laid out and used. This may be undertaken as part of the building design process, or as a stand-alone exercise looking at how best to plan an existing space, or a space that is being developed (for example, a tenant determining how to fit out their part of a new development). It can be used for very simple spaces such as hotel bedrooms, through to very complex industrial buildings. Good space planning can improve the wellbeing and productivity of the occupants of a space.
Dimensions in the construction industry - Ruler-146428 640.png
Ruler-146428 640.png -
A dimension is a derived unit used to measure a physical quantity such as length, width, height, distance, area, volume, mass and time.
Some of these units, such as area, can be obtained by the multiplication of two other dimensions, so for example (a x b) gives the area ab. Other measurements such as volume can be established by combining three linear measurements. The volume of say, a cylinder may be given by multiplying the area by the height (a x b x h).
A straight line has one dimension; an area has two dimensions and a volume has three.
Measuring velocity requires combining dimensions of length and time. Measuring force also requires combining various dimensions.
In construction, the dimensions most used are those concerning length to provide other dimensions of height, distance, area and volume. Measuring time is also important in construction, as is mass.
Dimensions are critical for co-ordinating building components and ensuring each fits correctly in its allocated place in a construction. Dimensionally co-ordinated products allow designers to select items which they can be confident will fit together (co-ordinate) dimensionally with the structure and other components to accepted tolerances.
Measurements are often included on drawings to give an overall understanding of size, or by wave of instruction to help workers setting out a project or manufacturing components.
The term lighting refers to equipment, the primary purpose of which, is to produce light. This is typically some form of lamp, but lighting can also refer to the use of natural light to provide illumination.
Light is the electromagnetic radiation that exists within a certain portion of the electromagnetic spectrum. In terms of 'visible light', i.e. that which enables the sense of sight, it is the part of the spectrum that can be detected and seen by the eye.
The level of light on a surface is described as Illuminance and is measured in lux (lx), where one lux is equal to one lumen per square metre (lm/m) and a lumen is the SI unit (International System) of luminous flux, describing the quantity of light emitted by a lamp or received at a surface.
In relation to external lighting, Urban Design Guidelines for Victoria, published by The State of Victoria Department of Environment, Land, Water and Planning in 2017 suggests that: Lighting performs a number of functions, from supporting way-finding, orientation and safe movement at night to providing a decorative effect for building facades, landmarks and paths. Lighting systems can be large- scale and utilitarian, or small and ornamental. They may use overhead lamps, bollards, up-lights, bulkhead or veranda lighting, feature and facade illumination. Shop display lighting can also contribute to overall public realm lighting levels. Lighting is critical to creating a public realm that is safe and inviting for users.
In general, the word step refers to the individual parts of a staircase that people step on. This is as opposed to stairs which are a flight of steps.
Steps can be constructed using a wide variety of materials, including; timber, brick, stone, concrete, metal, glass, and so on.
Individual steps are made up of a horizontal tread and a vertical riser. They are measured in terms of a going, i.e. the depth from front-to-back of the step (less any overlap with the next step above), a rise (the vertical distance between treads, and the width from one side to the other.
Components of stairs.jpg -
Steps should have level treads with the rise and going of each step consistent throughout the flight. The part of the tread that sometimes overhangs the riser is called the nosing. Depending on the design, the riser can be left open, or can be closed.
Some types of stairs (e.g. circular, spiral) can incorporate winders, which are steps that have one side narrower than the other. This allows the stairs direction to change without a landing.
The requirements for the design of steps are set out in the approved documents to the building regulations:
Approved document K: Protection from falling, collision and impact.
Approved document M: Access to and use of buildings (only when external stepped access also forms part of the principal entrances and alternative accessible entrances and when they form part of the access route to the building from the boundary of the site and car parking).
Approved document B: Fire safety. -
Uniclass is a voluntary classification system for the construction industry that can be used for all aspects of the design and construction process, including; organising documents in libraries, structuring project information, cost information, specifications, and so on. It was created in 1997 by Construction Project Information committee (CPIC).
Uniclass consists of 16 tables, some of which are derived from other classification systems such as CAWS, EPIC and CI/SfB:
A - Form of information - B - Subject disciplines
B - Subject disciplines - C - Management
C - Management - D - Facilities
D - Facilities - E - Construction entities
E - Construction entities - F - Spaces
F - Spaces - G - Elements for buildings
G - Elements for buildings - H - Elements for civil engineering works
H - Elements for civil engineering works - J - Work sections for buildings
J - Work sections for buildings - K - Work sections for civil engineering works
K - Work sections for civil engineering works - L - Construction Products
L - Construction Products - M - Construction aids
M - Construction aids - N - Properties and characteristics
N - Properties and characteristics - P - Materials
P - Materials - Q - Universal Decimal Classification
Q - Universal Decimal Classification - Z - Computer Aided Draughting
Z - Computer Aided Draughting - Uniclass Online a digitised, free edition of the Uniclass was made available by the The Royal Institute of British Architects (RIBA) and the CPI in 2012. Uniclass Online was funded by the Technology Strategy Board and intended to provide a free and integrated construction classification system to assist construction professionals, particularly those committed to Building Information Modelling (BIM) (Ref RIBA News)
Uniclass Online a digitised, free edition of the Uniclass was made available by the The Royal Institute of British Architects (RIBA) and the CPI in 2012. Uniclass Online was funded by the Technology Strategy Board and intended to provide a free and integrated construction classification system to assist construction professionals, particularly those committed to Building Information Modelling (BIM) (Ref RIBA News)
However, Uniclass has been criticised for not being genuinely unified, for inconsistencies between the labelling and depth of tables, for poor integration of civil engineering and building works and for being an essentially paper-based system. CPI undertook a consultation on proposed changes to address some of these issues, and published a new version, Uniclass 2 based on the following classification:
Co - Complexes - En - Entities
En - Entities - Ac - Activities
Ac - Activities - Sp - Spaces
Sp - Spaces - EF - Entities by Form
EF - Entities by Form - Ee - Elements
Ee - Elements - Ss - Systems
Ss - Systems - Pr - Products
Pr - Products - Zz - CAD
Zz - CAD - PP - Project Phases
PP - Project Phases - See Uniclass 2 for more information.
See Uniclass 2 for more information. -
However, Following feedback received about Uniclass 2, changes were made, and a new version, Uniclass 2015 released. The most significant change is the removal of the Work Results table.
NB the New Rules of Measurement (NRM2) has moved away from the common arrangement of work sections (CAWS - now incorporated into Table J of Uniclass) that was adopted by the Standard Method of Measurement (SMM7) and has adopted its own system of indexing.
Introduction - When people are dissatisfied with their thermal environment, not only is it a potential health hazard, it also impacts on their ability to function effectively, their satisfaction at work, the likelihood they will remain a customer, and so on.
When people are dissatisfied with their thermal environment, not only is it a potential health hazard, it also impacts on their ability to function effectively, their satisfaction at work, the likelihood they will remain a customer, and so on.
BS EN ISO 7730 defines thermal comfort as 'that condition of mind which expresses satisfaction with the thermal environment.', i.e. the condition when someone is not feeling either too hot or too cold.
The human thermal environment is not straight forward and cannot be expressed in degrees. Nor can it be satisfactorily defined by acceptable temperature ranges. It is a personal experience dependent on a great number of criteria and can be different from one person to another within the same space.
For example, a person walking up stairs in a cold environment whilst wearing a coat might feel too hot, whilst someone sat still in a shirt in the same environment might feel too cold.
The Health and Safety Executive (HSE) suggest that an environment can be said to achieve 'reasonable comfort' when at least 80% of its occupants are thermally comfortable. This means that thermal comfort can be assessed by surveying occupants to find out whether they are dissatisfied with their thermal environment.
Thermal comfort.jpg -
Factors influencing thermal comfort - Thermal comfort results from a combination of environmental factors and personal factors:
Thermal comfort results from a combination of environmental factors and personal factors:
Environmental factors - Air temperature
Air temperature - The temperature of the air that a person is in contact with, measured by the dry bulb temperature (DBT).
The temperature of the air that a person is in contact with, measured by the dry bulb temperature (DBT).
Air velocity - The velocity of the air that a person is in contact with (measured in m/s). The faster the air is moving, the greater the exchange of heat between the person and the air (for example, draughts generally make us feel colder).
The velocity of the air that a person is in contact with (measured in m/s). The faster the air is moving, the greater the exchange of heat between the person and the air (for example, draughts generally make us feel colder).
Radiant temperature - The temperature of a persons surroundings (including surfaces, heat generating equipment, the sun and the sky). This is generally expressed as mean radiant temperature (MRT, a weighted average of the temperature of the surfaces surrounding a person, which can be approximated by globe thermometer) and any strong mono-directional radiation such as radiation from the sun.
The temperature of a persons surroundings (including surfaces, heat generating equipment, the sun and the sky). This is generally expressed as mean radiant temperature (MRT, a weighted average of the temperature of the surfaces surrounding a person, which can be approximated by globe thermometer) and any strong mono-directional radiation such as radiation from the sun.
Relative humidity (RH) - The ratio between the actual amount of water vapour in the air and the maximum amount of water vapour that the air can hold at that air temperature, expressed as a percentage. The higher the relative humidity, the more difficult it is to lose heat through the evaporation of sweat.
The ratio between the actual amount of water vapour in the air and the maximum amount of water vapour that the air can hold at that air temperature, expressed as a percentage. The higher the relative humidity, the more difficult it is to lose heat through the evaporation of sweat.
Personal factors - Clothing
Clothing - Clothes insulate a person from exchanging heat with the surrounding air and surfaces as well as affecting the loss of heat through the evaporation of sweat. Clothing can be directly controlled by a person (i.e. they can take off or put on a jacket) whereas environmental factors may be beyond their control.
Clothes insulate a person from exchanging heat with the surrounding air and surfaces as well as affecting the loss of heat through the evaporation of sweat. Clothing can be directly controlled by a person (i.e. they can take off or put on a jacket) whereas environmental factors may be beyond their control.
Metabolic heat or level of activity - The heat we produce through physical activity. A stationary person will tend to feel cooler than a person who is exercising.
The heat we produce through physical activity. A stationary person will tend to feel cooler than a person who is exercising.
Wellbeing and sicknesses - Such as the common cold or flu which affect our ability to maintain a body temperature of 37C at the core.
Such as the common cold or flu which affect our ability to maintain a body temperature of 37C at the core.
Other contributing factors can include; access to food and drink, acclimatisation (this can be more difficult where there is a high outdoor-indoor temperature gradient) and state of health.
In addition, thermal comfort will be affected by whether a thermal environment is uniform or not. For example, draughts and heaters can create a scorched face / frozen back effect and hot feet/cold head and hands effect.
'Thermal alliesthesia' goes beyond this, proposing that the hedonic qualities of the thermal environment (qualities of pleasantness or unpleasantness, or 'the pleasure principle') are determined as much by the general thermal state of the subject as by the environment itself.
In its simplest form, cold stimuli will be perceived as pleasant by someone who is warm, whilst warm stimuli will be experienced as pleasant by someone who is cold. Introducing a spatial component to this, it can for example be pleasurable to wrap cool hands around a warm mug. See Thermal pleasure in the built environment for more information.
Controlling thermal comfort - Thermal comfort can be controlled or adjusted by a number of different measures:
Thermal comfort can be controlled or adjusted by a number of different measures:
Environmental monitoring and control (automated or user-controlled systems, active systems such as heating and cooling and passive systems such as shading). NB: User-controlled systems require that users are properly trained.
Adapting or changing clothing. Businesses can allow people to wear different clothing depending on conditions. They can also provide things like cloak rooms or lockers so that people can change clothes or take off and put down coats. The golden rule is layering, generally 3 layers, and use zips and buttons to regulate temperature.
Allowing flexible working hours or changing start and finish times.
Adjusting tasks. For example, allowing breaks or reducing the length of time people are exposed to particular conditions.
Providing information telling people what sort of conditions to expect so that they can dress and behave appropriately.
Providing or allowing personal equipment such as desk fans.
Separating people from sources of discomfort. For example, putting heat generating equipment such as ICT equipment in separate rooms, insulating pipes, preventing draughts and so on. NB: Draughts can be caused by high local surface temperature differences even in a space where there is no air infiltration for example, a cold down-draught near a window.
Providing protective clothing (PPE Personal Protective Equipment). This should be a last resort option.
Predicting thermal comfort - There are a great number of techniques for estimating likely thermal comfort, including; effective temperature, equivalent temperature, Wet Bulb Globe Temperature (WBGT), resultant temperature and so on, and charts exist showing predicted comfort zones within ranges of conditions.
There are a great number of techniques for estimating likely thermal comfort, including; effective temperature, equivalent temperature, Wet Bulb Globe Temperature (WBGT), resultant temperature and so on, and charts exist showing predicted comfort zones within ranges of conditions.
However, BS EN ISO 7730 and BS EN ISO 10551 suggest thermal comfort can be expressed in terms of Predicted Mean Vote (PMV) and Percentage People Dissatisfied (PPD).
PMV and PPD were developed by Professor Ole Fanger based on research undertaken at Kansas State University and the Technical University of Denmark. Research was carried out to find out if people felt comfortable in different conditions and this was used to develop equations that would predict comfort. The equations take into account; air temperature, mean radiant temperature, air movement, humidity, clothing and activity level.
PMV is an index that predicts the mean vote of a group of people voting on how comfortable they are in an environment. PPD is a function of PMV.
Where non-uniform conditions exist, multiple assessments may be necessary, and in complex environments, Computational Fluid Dynamics (CFD) analysis may be necessary to accurately assess thermal comfort.
NB BREEAM UK New Construction, Non-domestic Buildings (United Kingdom), Technical Manual, SD5078: BREEAM UK New Construction 2018 3.0, published by BRE Global Limited suggests that: 'In BS EN ISO 7730:2005: Ergonomics of the thermal environment. Analytical determination and interpretation of thermal comfort, thermal comfort is defined using the calculation of PMV and PPD indices and local thermal comfort criteria. It is also defined as that condition of mind which expresses satisfaction with the thermal environment. The term thermal comfort describes a persons psychological state of mind and is usually referred to in terms of whether someone is feeling too hot or too cold. Thermal comfort is difficult to define because it needs to account for a range of environmental and personal factors in order to establish what makes people feel comfortable. HSE considers 80% of occupants as a reasonable limit for the minimum number of people who should be thermally comfortable in an environment. The purpose of this issue is to encourage appropriate and robust consideration of thermal comfort issues, and specification of appropriate occupant controls to ensure both maximum flexibility of the space and thermal comfort for the majority of building occupants.'
It also suggests that: 'Thermal comfort analysis tools can be subdivided into a number of methods of increasing complexity. The most complex of these and the one that provides greatest confidence in results is the full dynamic model. This type of model enables annual heating or cooling loads, overheating risks and control strategies to be assessed.'
Regulation - Temperatures in the workplace are governed by the Workplace (Health, Safety and Welfare) Regulations 1992, which oblige employers to provide a reasonable temperature in the workplace.
Temperatures in the workplace are governed by the Workplace (Health, Safety and Welfare) Regulations 1992, which oblige employers to provide a reasonable temperature in the workplace.
The Approved Code of Practice (Workplace health, safety and welfare. Workplace (Health, Safety and Welfare) Regulations 1992. Approved Code of Practice ) suggests a minimum temperature of 16 degrees Celsius, or 13 degrees Celsius if work involves severe physical effort. However, these are only guidelines.
The Health and Safety Executive (HSE) previously defined thermal comfort in the workplace, as: 'roughly between 13C (56F) and 30C (86F), with acceptable temperatures for more strenuous work activities concentrated towards the bottom end of the range, and more sedentary activities towards the higher end.'
However, the complexity of thermal comfort means that there is no meaningful maximum guideline temperature, particularly at higher temperatures.
Introduction - Temperature is a measure of the average kinetic energy of molecules. This is important as the average temperature relates to the movement of molecules in a substance or material. A cup of boiling water will be hotter than the Atlantic Ocean but the latter will contain much more heat than the former.
Temperature is a measure of the average kinetic energy of molecules. This is important as the average temperature relates to the movement of molecules in a substance or material. A cup of boiling water will be hotter than the Atlantic Ocean but the latter will contain much more heat than the former.
Temperature will tend to vary throughout a body depending on its heat exchange with its surroundings. Temperature can be expressed in degrees Celsius (C), kelvin (k) or Fahrenheit (F), with Kelvin the scientific measure, Celsius being used as it relates to the properties of water, zero is freezing and 100 is steam..
Measuring temperature actually records the temperature of the sensor that is being used to carry out the measurement (usually a thermometer). As a consequence, different types of measurement and calculation have been developed to represent the temperature of different types of body. Some of these methods are described below.
Thermal comfort - Temperature can be a particularly important measure in the built environment when considering the thermal comfort of occupants and in the design of building services systems. As a consequence, many of the measures of temperature are intended to represent the thermal comfort of people, or some component of their thermal comfort. Thermal comfort is a complex science in its own right.
Temperature can be a particularly important measure in the built environment when considering the thermal comfort of occupants and in the design of building services systems. As a consequence, many of the measures of temperature are intended to represent the thermal comfort of people, or some component of their thermal comfort. Thermal comfort is a complex science in its own right.
Making a building comfortable is not as simple as delivering an average internal air temperature of 21 C throughout the year. Thermal comfort is dependent on a range of environmental factors in addition to air temperature, such as; air velocity, radiant temperature, relative humidity and the uniformity of conditions. It also depends on personal factors such as; clothing, metabolic heat, state of health, acclimatisation, expectations, and even access to food and drink. See thermal comfort for more information.
NB: Heat stress is a form of overheating that the occupants of a building may experience when the measures that their body uses to regulate internal temperature begin to fail. This can occur for example in buildings where an industrial process is being carried out, such as; smelting, brick-firing, cooking, and so on. See Heat stress for more information.
Measures of temperature - Dry-bulb temperature
Dry-bulb temperature - Dry-bulb temperature (Tdb, DBT or Td), is a measure of air temperature. It is referred to as dry-bulb temperature because the thermometer bulb is dry and so the temperature recorded does not vary with the moisture content of the air. See dry-bulb temperature for more information.
Dry-bulb temperature (Tdb, DBT or Td), is a measure of air temperature. It is referred to as dry-bulb temperature because the thermometer bulb is dry and so the temperature recorded does not vary with the moisture content of the air. See dry-bulb temperature for more information.
Wet-bulb temperature - Wet-bulb temperature (Twb or Tw) is the temperature recorded by a thermometer that has its bulb wrapped in cloth and moistened with distilled water. See wet-bulb temperature for more information.
Wet-bulb temperature (Twb or Tw) is the temperature recorded by a thermometer that has its bulb wrapped in cloth and moistened with distilled water. See wet-bulb temperature for more information.
Wet-bulb globe temperature - Wet-bulb globe temperature (WBGT) is an index that is widely used for the assessment of heat stress. It combines wet-bulb temperature, dry-bulb temperature and globe temperature. See wet-bulb globe temperature and heat stress for more information.
Wet-bulb globe temperature (WBGT) is an index that is widely used for the assessment of heat stress. It combines wet-bulb temperature, dry-bulb temperature and globe temperature. See wet-bulb globe temperature and heat stress for more information.
Mean radiant temperature - Mean radiant temperature (MRT) is a measure of the average temperature of the surfaces that surround a particular point. If the point is exposed to the outside, this may include the sky temperature and solar radiation. See mean radiant temperature for more information.
Mean radiant temperature (MRT) is a measure of the average temperature of the surfaces that surround a particular point. If the point is exposed to the outside, this may include the sky temperature and solar radiation. See mean radiant temperature for more information.
Globe temperature - Globe temperature (or black-globe temperature) was introduced as a means of assessing the combined effects of radiation, air temperature and air velocity as they influence human comfort. It is measured using a globe thermometer, a hollow copper sphere painted matt back to absorb radiant heat with a temperature sensor at its centre. This can be used in conjunction with air temperature and air velocity to calculate mean radiant temperature. See globe temperature for more information.
Globe temperature (or black-globe temperature) was introduced as a means of assessing the combined effects of radiation, air temperature and air velocity as they influence human comfort. It is measured using a globe thermometer, a hollow copper sphere painted matt back to absorb radiant heat with a temperature sensor at its centre. This can be used in conjunction with air temperature and air velocity to calculate mean radiant temperature. See globe temperature for more information.
Sling psychrometer - Sling psychrometers hold a wet-bulb thermometer and a dry-bulb thermometer. They can be used to determine the physical and thermal properties of moist air by using standard tables. See sling psychrometer for more information.
Sling psychrometers hold a wet-bulb thermometer and a dry-bulb thermometer. They can be used to determine the physical and thermal properties of moist air by using standard tables. See sling psychrometer for more information.
Thermal comfort - BS EN ISO 7730 defines thermal comfort as 'that condition of mind which expresses satisfaction with the thermal environment.', ie the condition when someone is not feeling either too hot or too cold. The Health and Safety Executive suggest that an environment can be said to achieve 'reasonable comfort' when at least 80% of its occupants are thermally comfortable. See Thermal comfort for more information.
BS EN ISO 7730 defines thermal comfort as 'that condition of mind which expresses satisfaction with the thermal environment.', ie the condition when someone is not feeling either too hot or too cold. The Health and Safety Executive suggest that an environment can be said to achieve 'reasonable comfort' when at least 80% of its occupants are thermally comfortable. See Thermal comfort for more information.
Operative temperature - Operative temperature (previously known as resultant temperature or dry resultant temperature, but renamed to align with ASHRAE and ISO standards) is a simplified measure of human thermal comfort derived from air temperature, mean radiant temperature and air speed. See operative temperature for more information.
Operative temperature (previously known as resultant temperature or dry resultant temperature, but renamed to align with ASHRAE and ISO standards) is a simplified measure of human thermal comfort derived from air temperature, mean radiant temperature and air speed. See operative temperature for more information.
Resultant temperature - A measure of thermal comfort now re-named 'operative temperature'. See operative temperature for more information.
A measure of thermal comfort now re-named 'operative temperature'. See operative temperature for more information.
Predicted mean vote - The predicted mean vote (PMV) is an empirical fit to the sensation of thermal comfort. It predicts the average vote of a large group of people on the a seven-point thermal sensation scale where +3 is hot and -3 is cold. See predicted mean vote for more information.
The predicted mean vote (PMV) is an empirical fit to the sensation of thermal comfort. It predicts the average vote of a large group of people on the a seven-point thermal sensation scale where +3 is hot and -3 is cold. See predicted mean vote for more information.
Running mean temperature - An exponentially-weighted outside running mean temperature can be used to account for the time-dependency of thermal comfort. Adaptive comfort theory suggests that the occupants of a building will adapt to their environment over time, adjusting clothing, modifying behaviour and so on and so might accept conditions that would otherwise have been predicted to be unsatisfactory. See running mean temperature for more information.
An exponentially-weighted outside running mean temperature can be used to account for the time-dependency of thermal comfort. Adaptive comfort theory suggests that the occupants of a building will adapt to their environment over time, adjusting clothing, modifying behaviour and so on and so might accept conditions that would otherwise have been predicted to be unsatisfactory. See running mean temperature for more information.
Accumulated temperature - Median accumulated temperature above 0C from January to June which gives a measure of heat energy input and soil drying potential and correlates with crop growth and yield.
Median accumulated temperature above 0C from January to June which gives a measure of heat energy input and soil drying potential and correlates with crop growth and yield.
Dry-bulb temperature (Tdb, DBT or Td), is a measure of air temperature. It is referred to as dry-bulb temperature because the thermometer bulb is dry and so the temperature recorded does not vary with the moisture content of the air. This is as opposed to wet-bulb temperature which is the temperature recorded by a thermometer that has its bulb wrapped in cloth and moistened with distilled water. Wet-bulb temperatures are the same as dry-bulb temperatures at a relative humidity of 100%, but otherwise wet-bulb temperatures will be lower than dry-bulb temperatures due to the cooling effect of evaporation (described as wet-bulb depression).
A sling psychrometer holds both wet and dry-bulb thermometers and can be used to express the physical and thermal properties of moist air on a psychrometric chart.
Dry-bulb temperature can be measured by a thermometer exposed to the air but shielded from radiation and moisture. It can be expressed in Celsius (C), Fahrenheit (F) or Kelvin (K).
Dry-bulb temperature can be used as to express a component of thermal comfort. For example, the wet bulb globe temperature index (WBGT) is widely used for the assessment of heat stress and combines wet-bulb temperature, dry-bulb temperature and globe temperature (mean radiant temperature).
Moisture is the presence of water, often in small or even trace amounts. Moisture can be found in water vapour, condensation, and in or on the fabric of a building and can cause damp resulting in problems such as staining, mould growth, mildew and poor indoor air quality, and so on.
The common sources of moisture in buildings include:
Condensation. - Penetrating damp.
Penetrating damp. - Leakage from pipes, tanks, drains, and so on.
Leakage from pipes, tanks, drains, and so on.
Rising damp. - Building defect, e.g. lack of adequate roof space ventilation, faulty retrofit installation, application of paint or plaster that affects the breathability of the building element, and so on.
Building defect, e.g. lack of adequate roof space ventilation, faulty retrofit installation, application of paint or plaster that affects the breathability of the building element, and so on.
Indoor moisture sources, e.g. cooking, bathing, washing, hot tubs, indoor swimming pools, and so on..
Moisture levels can be reduced through a number of measures:
Natural or mechanical ventilation. - Use of de-humidifiers or air conditioning units.
Use of de-humidifiers or air conditioning units. - Insulation of cold surfaces, such as pipes.
Insulation of cold surfaces, such as pipes.
Increasing air temperature. - Removing sources of moisture such as drying clothes and ensuring vented tumble dryers are appropriately vented to the outside.
Removing sources of moisture such as drying clothes and ensuring vented tumble dryers are appropriately vented to the outside.
Mending leaking pipes, wastes and overflows. - Eliminating rising damp and penetrating damp.
Eliminating rising damp and penetrating damp. - Introducing moisture barriers such as vapour barriers, damp proof membranes, and so on.
Introducing moisture barriers such as vapour barriers, damp proof membranes, and so on.
NB Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines moisture as: Water that is freely mobile as a liquid, gas (vapour), and solid (ice). All moisture is water, but not all water is moisture, as it is not necessarily freely mobile.
It defines moisture content as: The quantity of moisture present within a material.
The term fresh air is commonly used to refer to air that is outside (or from outside) a building or enclosed space, as opposed to that which is inside. In order to ensure a good supply of fresh air, buildings need to be properly ventilated. Sometimes air that is not fresh is referred to as 'stale air'.
The provision of fresh air in a building is important to occupants wellbeing and has several benefits, including:
Increasing oxygen availability and removing carbon dioxide. - Maintaining a comfortable temperature.
Maintaining a comfortable temperature. - Enabling optimum brain functioning, increasing energy levels and improving concentration.
Enabling optimum brain functioning, increasing energy levels and improving concentration.
Diluting and removing odours. - Helping to moderate internal humidity.
Helping to moderate internal humidity. - Reducing the accumulation of moisture, bacteria, dust, smoke and other contaminants.
Reducing the accumulation of moisture, bacteria, dust, smoke and other contaminants.
Insufficient fresh air can result in occupants feeling tired, experiencing headaches, irritated eyes, and so on.
The Workplace (Health, Safety and Welfare) Regulations 1992 require that an employer does what is needed to make sure that every enclosed workplace is ventilated by a sufficient quantity of fresh or purified air. It states that the fresh air supply rate should not normally fall below 5-8 litres per second, per occupant. The appropriate rate should be decided by several factors, such as the amount of floor space per occupant, the work activity, possible sources of airborne hazards, and so on.
Stale air (sometimes called vitiated air) is air that has been affected by human, animal, mechanical or other activities, the effect of which requires that the air is replaced with fresh air to ensure optimal conditions. This might be the result of perspiration, smoking, cooking, use of appliances, musky carpets and fabrics, lack of ventilation and so on.
In their calculations for air extraction, services engineers may consider specific volumes of stale air in m2 to be extracted per hour. They typically work to achieve desirable minimum fresh-air requirements for people and these will vary according to the activities concerned. These ventilation rates or air-change rates determine how many times per hour the stale air in a space should be completely replaced by fresh air.
Approximate air-change rates per hour for various accommodations:
Accommodation Air-change rates per hour - Factories (large, open) 1-4
Factories (large, open) 1-4 - Classrooms and libraries 2-4
Classrooms and libraries 2-4 - Offices (above ground) 2-6
Offices (above ground) 2-6 - Public lavatories 6-12
Public lavatories 6-12 - Restaurants 10-15
Restaurants 10-15 - Kitchens 20-60
Kitchens 20-60 - Air change rates may need adjustment according to specific conditions that might prevail eg whether smoking will take place or the presence of other fumes. Also, higher levels of relative humidity (ie above 70%) may require higher ventilation rates to reduce the water vapour content in the air.
Air change rates may need adjustment according to specific conditions that might prevail eg whether smoking will take place or the presence of other fumes. Also, higher levels of relative humidity (ie above 70%) may require higher ventilation rates to reduce the water vapour content in the air.
Ventilation - Ventilation is necessary in buildings to remove 'stale' air and replace it with 'fresh' air.
Ventilation is necessary in buildings to remove 'stale' air and replace it with 'fresh' air.
This helps to: -
Moderate internal temperatures. - Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Create air movement which improves the comfort of occupants.
Very broadly, ventilation in buildings can be classified as 'natural' or 'mechanical'.
Mechanical (or 'forced') ventilation tends to be driven by fans.
Natural ventilation is driven by 'natural' pressure differences from one part of the building to another. Natural ventilation can be wind driven, or buoyancy driven. For more information, see Natural ventilation.
Whilst natural ventilation may be preferable, mechanical ventilation may be necessary where:
The building is too deep to ventilate from the perimeter.
Local air quality is poor, for example, if a building is next to a busy road.
Local noise levels mean that windows cannot be opened.
The local urban structure is very dense and shelters the building from the wind.
Air cooling or air conditioning systems mean that windows cannot be opened.
Privacy or security requirements prevent windows being opened.
Internal partitions block air paths. - The creation of draughts adjacent to openings.
The creation of draughts adjacent to openings. - NB: Some of these issues can be avoided or mitigated by careful siting and design of buildings.
NB: Some of these issues can be avoided or mitigated by careful siting and design of buildings.
'Mixed-mode' ventilation uses both natural and mechanical ventilation, for example, allowing the opening of windows, but also providing a mechanical air distribution system.
The term 'assisted ventilation' typically refers to systems where fresh air enters a building through windows or other openings, but is extracted by continuously running fans.
'Trickle ventilation', 'slot ventilators' or 'background' ventilation can be necessary in modern buildings (which tend to be designed to be almost completely sealed from the outside to reduce heat loss or gain), so that problems such as condensation are avoided when openings are closed.
This tendency to 'seal' modern buildings can also adversely affect occupant comfort, as generally, occupants feel more comfortable if there is some air movement (as long as draughts are not created). This situation can be mitigated by heat recovery ventilation (HRV). This permits increased ventilation rates by recovering heat from extract air and using it to pre-heat incoming fresh air using counter-flow heat exchangers. Heat recovery is increasingly common in mechanical ventilation systems. It is also possible, although complicated with some natural ventilation systems.
Ventilation systems may also include heating, cooling, filtration and humidity control. The acronym HVAC refers to Heating Ventilation and Air Conditioning. The phrase 'air conditioning' refers to the process of conditioning the temperature and humidity (and sometimes the quality) of air before using it to ventilate a building. Air conditioning and cooling are not the same, although the terms are often used synonymously by non-professionals.
Rates of ventilation in buildings can be expressed in terms of air change rates (the number of times that the volume of air in a space is changed per hour) or litres per second. The ventilation rate will be determined by the type and size of space and the way it is occupied (for example, the number of occupants, sources of heat, moisture, odour, contaminants, and so on). Ventilation in buildings is regulated by Part F of the Building Regulations.
Whilst there are simple 'rules of thumb' that can be used to design straight-forward ventilation systems, more complex systems may require analysis using environmental design software. Modelling air flow patterns is particularly complex requiring the use of computational fluid dynamics software.
This is complicated further by the interaction of ventilation systems with thermal mass, solar radiation, and so on. Whilst there are software packages that can be used for this sort of analysis, the results they produce are very dependent on the way that models are set up, and this requires a great deal of expertise and experience.
Designers tune the thermal characteristics of buildings so they moderate external environmental conditions and maintain internal conditions using the minimum resources of materials and fuel. Generally, this is achieved by a combination of thermal mass, thermal insulation and active and passive building services systems.
Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even-out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. In building design, this can be useful to even-out and delay extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems.
Thermal mass can be used to store high thermal loads by absorbing heat introduced by external conditions, such as solar radiation, or by internal sources such as appliances and lighting, to be released when conditions are cooler. This can be beneficial both during the summer and the winter.
Thermal mass can be introduced to store a specific aspect of thermal energy. For example, a trombe wall placed in front of a south-facing window will absorb solar radiation and then slowly re-release it into the enclosed space. It can also be used in combination with ventilation strategies, for example, concrete floor slabs can be used to absorb heat gains during the day. This heat can then be vented to the outside during the night, leaving the mass available to absorb more heat the following day.
Historically, it has been considered that buildings with more thermal mass are suited to regular occupation, where internal conditions are stabilised by the thermal mass, and moderated by low-level building services inputs. Lighter-weight, more highly-insulated buildings might be better suited to occasional use, where occupants return after some absence and at the flick of a switch, can activate building services systems that will quickly create comfortable conditions.
Night-time cooling, however, may require that buildings are unoccupied during the night, and so may be more suitable for an office building than for a hospital, and as the building regulations become more strict, so the performance differences between lightweight and heavyweight buildings are becoming more blurred.
The position is complicated further, as external conditions change throughout the seasons and time of day, meaning for example, that the building envelope may sometimes be required to contain heat, sometimes to capture it, and sometimes to reject it. And the building fabric may have to do this at the same time as performing multiple, conflicting roles, such as allowing access, providing security and creating a suitable acoustic environment.
The thermo-dynamics of thermal mass is a complex subject. The usefulness of materials for storing heat is based on the relationship between their thermal properties and the thermal cycle that they are required to moderate. Thermal mass requires high specific heat capacity, high density and a thermal conductivity that means heat flows into and out of the material are aligned with the thermal cycle of the occupied space. Materials such as concrete and masonry tend to have a useful thermal mass, whereas timber is too slow an absorber of heat, and steel has a too high a thermal conductivity.
The ability of a material to absorb and release heat through thermal cycles is described as 'admittance' and is based on its:
Thermal capacity. - Thermal conductivity.
Thermal conductivity. - Density.
Density. - Surface resistance.
Surface resistance. - Thickness.
Thickness. - It is generally considered that in the UK, with a 24-hour thermal cycle, heat energy can only penetrate up to 100mm into thermal mass such as concrete and masonry. This thickness that can be found in most buildings. The delay in peak temperatures (the admittance time lead) can be up to six hours.
It is generally considered that in the UK, with a 24-hour thermal cycle, heat energy can only penetrate up to 100mm into thermal mass such as concrete and masonry. This thickness that can be found in most buildings. The delay in peak temperatures (the admittance time lead) can be up to six hours.
However, thermal mass must be exposed to function efficiently. This means that it is commonly associated with exposed concrete floors, and walls, rather than conventional spaces which might include wall linings, suspended ceilings and raised floors. This requires that a high-quality finish is achieved and that services are carefully routed. The effectiveness of thermal mass can, however, be enhanced by paint, selected to optimise the absorption and release of thermal radiation.
NB: The presence of exposed mass within buildings can cause problems with high acoustic reverberation.
Thermal mass is often used in association with a wider environmental design strategy that may include active, passive or mixed mode systems. Where it is associated with night-time cooling, it may be ideally suited to narrow, open-plan buildings or open-plan buildings with atria allowing natural ventilation. Care must be taken that there is no unwanted night-time cooling, leading to an increase in heating demand. This can be achieved by good insulation and good standards of workmanship to reduce infiltration.
There are also more complex design strategies that use thermal mass, such as thermal labyrinths and other ground energy options.
Strategies using thermal mass can be hampered by location (for example, if natural ventilation is not possible), orientation, acoustic considerations, or a requirement for cellular spaces or air-conditioning.
NB Climate Emergency Design Guide: How new buildings can meet UK climate change targets, published by the London Energy Transformation Initiative (LETI) in January 2020 defines thermal mass as: 'A property of the a material in a building which enables it to store heat, providing inertia against temperature fluctuations. It will absorb thermal energy when the surroundings are higher in temperature than the mass, and give thermal energy back when the surroundings are cooler.'
Specific heat capacity - The term specific heat (or specific heat capacity) refers to the heat energy per unit mass (typically 1 kg) required to raise the temperature of a substance by one degree Celsius.
The term specific heat (or specific heat capacity) refers to the heat energy per unit mass (typically 1 kg) required to raise the temperature of a substance by one degree Celsius.
The higher the specific heat capacity of a substance, the more energy is required to raise its temperature.
Specific heat capacity (c) in J (joules) / kg C can be calculated as:
c = E/m -
Where: -
E is the energy transfer in J. - m is the mass of the substances in kg.
m is the mass of the substances in kg.
is the temperature change in C. - Some examples of the specific heat capacities of different substances are listed below:
Some examples of the specific heat capacities of different substances are listed below:
Aluminum 902 J/kgC - Copper 385 J/kgC
Copper 385 J/kgC - Gold 129 J/kgC
Gold 129 J/kgC - Iron 450 J/kgC
Iron 450 J/kgC - Lead 128 J/kgC
Lead 128 J/kgC - NaCl 864 J/kgC
NaCl 864 J/kgC - Oxygen 918 J/kgC
Oxygen 918 J/kgC - Water 4181 J/kgC
Water 4181 J/kgC - Brick / block: 840 J/kgC
Brick / block: 840 J/kgC - Concrete: 880 J/kgC
Concrete: 880 J/kgC - Marble: 880 J/kgC
Marble: 880 J/kgC - Steel: 480 J/kgC
Steel: 480 J/kgC - Timber: 1200 J/kgC
Timber: 1200 J/kgC - Specific heat capacity is one of the properties that contributes to the thermal mass of a material, that is, how much heat it can store. Water, which has a very high specific heat capacity, is very effective at storing heat.
Specific heat capacity is one of the properties that contributes to the thermal mass of a material, that is, how much heat it can store. Water, which has a very high specific heat capacity, is very effective at storing heat.
Waste hierarchy - The waste hierarchy (sometimes simplified as 'reduce, re-use, recycle') sets out an order of preference for actions to reduce and manage waste. The overall aim of the hierarchy is to generate the minimum waste possible by using every material in every way possible. The most preferable option is 'prevention', at the top of the hierarchy with the least preferable 'disposal' at the bottom.
The waste hierarchy (sometimes simplified as 'reduce, re-use, recycle') sets out an order of preference for actions to reduce and manage waste. The overall aim of the hierarchy is to generate the minimum waste possible by using every material in every way possible. The most preferable option is 'prevention', at the top of the hierarchy with the least preferable 'disposal' at the bottom.
The waste hierarchy illustrated below is from the Defra 2011 publication.
Waste hierarchy.jpg -
Recycling - A recycled material is one that is adapted or transferred to a new use after its former use has been brought to an end. The new use may be similar to the former use (e.g recycled bricks used in new construction work) or it may be completely different, e.g steel which was once a universal column or beam recycled into automobile panels.
A recycled material is one that is adapted or transferred to a new use after its former use has been brought to an end. The new use may be similar to the former use (e.g recycled bricks used in new construction work) or it may be completely different, e.g steel which was once a universal column or beam recycled into automobile panels.
Recycling can help make a positive environmental impact on the planet. It saves resources, reduces waste, minimises air and water pollution and, because fewer, new resources are consumed for manufacture, it reduces carbon emissions.
A building may be deconstructed if it has reached the end of its life or is deemed no longer to be useful. In either case, it may not mean that the building can no longer serve its original function, rather, economics have dictated that a new building may bring more financial returns or a greater general benefits. In either case, deconstructing the building may yield a rich harvest of materials that can be recycled, depending on the original construction technique. Metals can be recycled relatively easily, bricks, roof tiles and roof slates can be reused, but wood if it has been fastened excessively with nails or strong adhesive can be very difficult to remove without damage. (Wood fragments can be broken down into strands to make new structural timber components such as laminated veneer lumber (LVL)).
Buildings can be designed for deconstruction, ensuring that it is as easy as possible to recycle or re-use their component parts. For more information see: Design for deconstruction.
Materials that can be directly recycled include metals (especially aluminium and steel), glass, paper, cardboard, plastics, electronics, batteries, textiles and tyres. A more indirect form of recycling is the composting or other conversion of biodegradable waste e.g food and garden waste.
Standards offer recycling guidance such as ISO 15270:2008 for plastic waste and ISO 14001:2015 for environmental management control of recycling.
In recent years, general recycling has been greatly facilitated by recycling centres that allow the public to discard their waste responsibly rather than just throwing it into the rubbish to end up in landfill. Household collections also encourage recycling of a host of recyclable materials including paper, cardboard, glass, plastic packaging, and food waste.
Ending the linear economy - Recycling challenges the old linear economy model comprising 'make, use and dispose'. In that system, the earths limited resources are, in the long run, wasted as the product usually ends up in landfill. Recycling (and reuse) break this mould, as once the life of a product in a first use is over, it can be recycled (or remanufactured) for a new life in another use.
Recycling challenges the old linear economy model comprising 'make, use and dispose'. In that system, the earths limited resources are, in the long run, wasted as the product usually ends up in landfill. Recycling (and reuse) break this mould, as once the life of a product in a first use is over, it can be recycled (or remanufactured) for a new life in another use.
Circular economy - Recycling is part of the circular economy as in theory products like steel, aluminium and paper may be recycled many times with little wastage at each reprocessing point.
Recycling is part of the circular economy as in theory products like steel, aluminium and paper may be recycled many times with little wastage at each reprocessing point.
The circular economy is a concept in which everything is engineered to be constantly reused or recycled. It requires rethinking of design, manufacturing, selling, re-using, recycling and consumer ownership to keep resources in use for as long as possible and to extract maximum value.
Building services are the systems installed in buildings to make them comfortable, functional, efficient and safe.
Building services might include: -
Building control systems. - Energy distribution.
Energy distribution. - Energy supply (gas, electricity and renewable sources such as solar, wind, geothermal and biomass).
Energy supply (gas, electricity and renewable sources such as solar, wind, geothermal and biomass).
Escalators and lifts. - Facade engineering (such as building shading requirements).
Facade engineering (such as building shading requirements).
Fire safety, detection and protection. - Heating, ventilation and air conditioning (HVAC).
Heating, ventilation and air conditioning (HVAC).
Information and communications technology (ICT) networks.
Lighting (natural and artificial). - Lightning protection.
Lightning protection. - Refrigeration.
Refrigeration. - Security and alarm systems.
Security and alarm systems. - Water, drainage and plumbing (including sustainable urban drainage systems (SUDS)).
Water, drainage and plumbing (including sustainable urban drainage systems (SUDS)).
Carbon emissions calculations and reduction. - For more information, see Types of building services.
For more information, see Types of building services.
Specialist building services might also include systems for bacteria and humidity control, specialist lighting and security, emergency power, specialist gas distribution, fume cupboards, operating theatres, and so on.
Building services play a central role in contributing to the design of a building, not only in terms of overall strategies and standards to be achieved, but also in faade engineering, the weights, sizes and location of major plant and equipment, the position of vertical service risers, routes for the distribution of horizontal services, drainage, energy sources, sustainability, and so on.
This means that building services design must be integrated into the overall building design from a very early stage, particularly on complex building projects such as hospitals. Whilst it is usual for a building design team to be led by an architect, on buildings with very complex building services requirements a building services engineer might be appointed as the lead designer.
The detection of clashes between building services and other building components is a significant cause of delays and variations on site, not just in terms of the physical services themselves, but also access to allow the builders work in connection with those services. The use of 3D computer aided design (CAD) systems and building information modelling (BIM) should help reduce the occurrence of such problems.
Increasingly, building services engineers are central to the design and assessment of sustainable systems, assessing the life cycle of buildings and their component services to minimise the resources consumed and the impact on the environment during fabrication, construction, operation and dismantling.
According to The Chartered Institute of Building Services Engineers (CIBSE):
'In any new construction project, building services typically account for 30-40% of the total cost.' (Ref. CIBSE fact sheet) and buildings account for almost 50% of carbon emissions (Ref. CIBSE).
As a consequence, many aspects of building services design are regulated (the building regulations, the energy related products regulations, and so on), and clients may impose their own standards on top of these regulations or seek certification under schemes such the Building Research Establishments (BRE) Environmental Assessment Method (BREEAM).
Ensuring that building services meet the standards set can involve the use of sophisticated simulation tools to predict the likely performance of buildings during the design stages (including the assessment and comparison of different options), as well as monitoring actual performance in use.
However, clients and designers are becoming increasingly aware of a disparity between the predicted and actual performance of buildings, with many buildings using considerably more energy than had been expected (up to 5 times as much according to the Carbon Trusts Low Carbon Buildings Accelerator and the Low Carbon Buildings Programme).
This may be as a result of the following:
A lack of proper understanding of building design and the interaction between components.
Poor prediction tools. - Inadequate detailing.
Inadequate detailing. - Discrepancies between specifications and actual construction.
Discrepancies between specifications and actual construction. - Poor build quality.
Poor build quality. - The use of idealised performance data for products.
The use of idealised performance data for products.
Improper user behaviour or operation. - Unexpected power loads (such as additional ICT equipment, external lighting, and so on).
Unexpected power loads (such as additional ICT equipment, external lighting, and so on).
The collection of more data to feedback information about performance in use will be necessary to rectify this problem.
NB: Building services will have to be upgraded and equipment replaced a number of times in the life of most buildings, building services engineers should consider this throughout design development as well as ease of maintenance and running costs.
Building management systems BMS - Building services are systems installed in buildings to make them comfortable, functional, efficient and safe. They can be controlled by simple mechanisms such as manual switching, clocks or detectors such as thermostats or motion detectors, or they can be controlled by more complex building management systems (BMS).
Building services are systems installed in buildings to make them comfortable, functional, efficient and safe. They can be controlled by simple mechanisms such as manual switching, clocks or detectors such as thermostats or motion detectors, or they can be controlled by more complex building management systems (BMS).
Building management systems are computer-based systems used to monitor and control building services such as:
Lighting. - Heating, ventilation and air conditioning (HVAC).
Heating, ventilation and air conditioning (HVAC).
Fire, smoke detection and alarms. - Motion detectors, CCTV, security and access control.
Motion detectors, CCTV, security and access control.
ICT systems. - Lifts.
Lifts. - Industrial processes or equipment.
Industrial processes or equipment. - Shading devices.
Shading devices. - Smart meters.
Smart meters. - They may also be used to monitor and control power distribution, energy consumption and uninterrupted power supplies (UPS) and may be referred to as building energy management systems (BEMS).
They may also be used to monitor and control power distribution, energy consumption and uninterrupted power supplies (UPS) and may be referred to as building energy management systems (BEMS).
NB: The phrase Building Energy Management Systems is sometimes used interchangeably with Building Management Systems (BMS), however, strictly speaking, Building Management Systems can be used to monitor and control a wide range of building systems whereas Building Energy Management Systems relate specifically to energy-related systems such as HVAC, lighting and power systems.
Building management systems help building managers understand how buildings are operating and allow them to control and adjust systems to optimise their performance. As well as collating data and allowing ease of control, BMS can help; visualise data, automatically generate reports and create alarms and alerts when parameters are exceeded, failures occur, or with prognostic systems, when failures are likely to occur. They can also allow comparison between spaces, buildings and benchmark data.
Intelligent building management systems bring together information and controls relating to a number of different systems operating using a range of different software applications and allow them to be controlled form single interface. This makes monitoring and analysis more straightforward and comprehensive and allows information from one system to influence the controls for another.
The effectiveness of BMS will depend on the range and quality of the information it receives from sensors and the programming of how this information is used. For example, information about external and internal conditions can be used to determine the level of heating required so that plant can be activated and a building pre-heated before occupants arrive.
Historically, BMS has been associated with large commercial buildings, however as equipment has become easier to control, monitoring and detection has become less expensive, and wireless technology has become available, buildings of all sizes are having increasingly complex control systems installed. This can for example allow home owners to connect to their home and switch on devices such as lights and heating before they arrive. See internet of things and smart buildings for more information.
BMS can help: -
Give better control of systems and conditions. - Data gathering and report generation.
Data gathering and report generation. - Increased productivity.
Increased productivity. - Allow better informed response to complaints.
Allow better informed response to complaints. - Allow allocation of operating costs within a business or to tenants.
Allow allocation of operating costs within a business or to tenants.
Allow more targeted use of resources for replacement and maintenance of equipment.
Early detection of issues. - Reduced operating costs and carbon emissions.
Reduced operating costs and carbon emissions. - Improved equipment life.
Improved equipment life. - Improve safety.
Improve safety. - Building management systems may now be integrated with building information models (BIM) to allow performance in use to be compared with design criteria and design simulations. This can help identify potential problems in operation or design and can help validate modelling techniques. Building information models might also include information about the operation and maintenance of building components.
Building management systems may now be integrated with building information models (BIM) to allow performance in use to be compared with design criteria and design simulations. This can help identify potential problems in operation or design and can help validate modelling techniques. Building information models might also include information about the operation and maintenance of building components.
Introduction - It is thought that in the UK, buildings account for around 50% of the total energy consumed (ref. CIBSE). The UK construction industry is the largest consumer of resources, consuming more than 400 million tonnes of material a year (ref. Davis Langdon), and this consumption of materials in itself accounts for around 10% of UK carbon emissions (ref. ENVEST from ICE).
It is thought that in the UK, buildings account for around 50% of the total energy consumed (ref. CIBSE). The UK construction industry is the largest consumer of resources, consuming more than 400 million tonnes of material a year (ref. Davis Langdon), and this consumption of materials in itself accounts for around 10% of UK carbon emissions (ref. ENVEST from ICE).
The energy consumed by a building throughout its life comprises:
Initial embodied energy: The energy consumed to create the building, including; extraction, processing and manufacture, transportation and assembly.
Recurring embodied energy: That is the energy consumed in refurbishing and maintaining the building during its life.
Operational energy: The energy consumed in heating, cooling, lighting and powering appliances in the building.
Demolition energy: The energy consumed in the disposal of the building.
The full, life-cycle cradle-to-grave embodied energy a building therefore is the initial embodied energy plus the recurring embodied energy plus the demolition energy.
For more information, see Cradle-to-grave. -
Embodied energy in buildings was first considered when the industry began to undertake detailed life cycle assessments, evaluating the whole-life environmental load of buildings. It had been assumed that service and maintenance operations during a buildings life consumed considerably more energy than the processes used to construct it (ref. The Living Rainforest, 2013), however, assessment revealed that this was not always true, with some building's embodied energy equating to several years of maintenance.
As regulation and improvements in efficiency reduce the amount of energy buildings use in operation, so embodied energy becomes relatively more significant. If zero carbon buildings become a reality, all attention will be focussed on embodied energy.
A study of Swedish low-energy buildings found that in one case the initial embodied energy was as much as 40% of the energy consumed by the building through its 50-year life (ref. Thormark 2002).
In the UK, a study found that the embodied energy in some commercial buildings was much as 30 times the annual operational energy use (ref. Rawlinson 2007).
Measurement - The process of assessing embodied energy involves measuring or estimating the total energy consumed in the life-cycle of a product. This may include gas, electricity, oil, and so on, but can also include features that may not be as easy to quantify, such as water use and ecological impact.
The process of assessing embodied energy involves measuring or estimating the total energy consumed in the life-cycle of a product. This may include gas, electricity, oil, and so on, but can also include features that may not be as easy to quantify, such as water use and ecological impact.
The measurement process involves assessing the relevant production means, which may include but is not limited to:
Extraction. - Manufacturing (including the energy to manufacture capital equipment, heating and lighting of factories, and so on)
Manufacturing (including the energy to manufacture capital equipment, heating and lighting of factories, and so on)
Transportation. - Construction.
Construction. - Maintenance.
Maintenance. - Disposal.
Disposal. - Some assessment methods exclude maintenance and disposal, but this is not ideal.
Some assessment methods exclude maintenance and disposal, but this is not ideal.
The full measure of the energy processes involved in the various stages of a product's life is often referred to as 'cradle-to-grave'. However, the embodied energy of products is often specified in terms of 'cradle-to-gate, that is, the energy consumed until the product leaves the factory gate. An alternative measure is cradle-to-site, which is the energy consumed until the product reaches the construction site.
NB: Life cycle assessments, evaluate all impacts over the whole life of a product or element. In a full life cycle assessment, the energy and materials used, along with waste and pollutants produced as a consequence of a product or activity are quantified over the whole life cycle (see Life cycle assessment for more information).
A further complication is the concept of embodied carbon. This refers to the carbon dioxide emitted as a consequence of sourcing and processing materials or products, concerned with mechanical and chemical operations and the by-products these create.
The terms embodied energy and embodied carbon produce very different figures. For example, cement has an embodied energy of 4.5 MJ/kg but has an embodied carbon value of 0.73 kg CO2/kg (ref. The University of Bath ICE, 2013). Correctly measuring embodied carbon includes consideration of the sequestration of carbon within materials such as timber as well as chemical reactions such as the carbonation of concrete.
The units of measurement for embodied energy are represented as megajoule per kilogram (MJ/kg). This is the energy density of a material. Embodied energy can also be expressed in terms of MJ/m2.
There are number of tools that have been developed to help assess embodied energy:
The Building Research Establishment software Envest II. - The University of Bath has produced an Inventory of Carbon & Energy (ICE) which uses a cradle-to-site approach.
The University of Bath has produced an Inventory of Carbon & Energy (ICE) which uses a cradle-to-site approach.
Design considerations - Calculation of embodied energy is very complex, and is just one of the environmental indicators that designers must consider when specifying materials and components for a building.
Calculation of embodied energy is very complex, and is just one of the environmental indicators that designers must consider when specifying materials and components for a building.
Other considerations might include the deleterious nature of some materials, difficulty of disposal, ecological impact, waste generation, recycled component and recyclability, renewable resources, locally sourced materials, ease of deconstruction and separation, durability, efficiency in use, standardisation, and so on (see Sustainable materials for more information).
A higher embodied energy material or component may sometimes be justified, for example if it reduces operational energy requirements (such as higher efficiency building services, high performance glazing, or high durability aluminium). Whilst lightweight building materials may tend to have a lower embodied energy, they might result in higher heating or cooling requirements, whilst heavyweight construction can even out diurnal temperature swings and so reduce overall energy consumption.
NB Climate Emergency Design Guide: How new buildings can meet UK climate change, published by The London Energy Transformation Initiative (LETI) in January 2020 defines upfront embodied carbon as: The carbon emissions associated with the extraction and processing of materials, the energy and water consumption used by the factory in producing products, transporting materials to site, and constructing the building.
Fan coil unit - Air handling units (AHU, sometimes referred to as air handlers) form part of the heating, ventilating and air conditioning system (HVAC) that supplies, circulates and extracts air from buildings. Generally, they are connected to the ductwork that supplies air to and extracts air from the interior and can provide ventilation, heating, cooling, humidity control and filtration. For more information see Air handling unit.
Air handling units (AHU, sometimes referred to as air handlers) form part of the heating, ventilating and air conditioning system (HVAC) that supplies, circulates and extracts air from buildings. Generally, they are connected to the ductwork that supplies air to and extracts air from the interior and can provide ventilation, heating, cooling, humidity control and filtration. For more information see Air handling unit.
Fan coil units (FCU) consist of only a fan and a heating or cooling element, are located within the space they are serving, and are generally not connected to ductwork. They may either just recirculate internal air, in which case a separate ventilation system is required, or may introduce s proportion of fresh air that is mixed with the recirculated air.
Fan coil units can be wall-mounted, freestanding or ceiling-mounted and may be concealed in ceiling voids. They may be controlled by local thermostats or by a building management system (BMS).
Due to their simplicity, fan coil units are more economical to install than ducted air handling units. However, they can be noisy and can create vibrations because the fan is in the occupied space.
Where fan coil units are supplied with chilled water and hot water from central boilers and chillers they are generally referred to as two pipe (either heating or cooling) or four pipe (both heating and cooling) units.
Where the heating and cooling is provided locally, they may be referred to as variable refrigerant volume (VRV) or variable refrigerant flow (VRF) systems. Here, refrigerant is circulated between one or more fan coil units and is connected to an external heat exchanger. These systems may be more prone to refrigerant leakage than units that are connected to hermetically-sealed central chillers.
Fan coil units are relatively compact and straightforward to install. However, they require regular maintenance to ensure continued efficient operation.
When a fan coil unit cools air, it will generally cause condensation which must be collected and drained or pumped away.
Thermal conduction in buildings - Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.
Thermal conduction is the diffusion of internal heat within a static (rather than fluid) body as a result of a temperature difference across it. Heat will tend to diffuse from higher temperature parts of a body to lower temperature parts.
This is particularly important in buildings where there may be a temperature difference between the inside and outside, for example, in a heated building during the winter, or in a cooled building during the summer.
Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.
Simple conductive heat transfer (in watts) through a uniform body can be calculated from Fourier's Law:
q = k A dT / s -
Where: -
A is the area of the body (m2)
k is the body's thermal conductivity (W/mC)
dT is the temperature difference across the body (C)
s is the body's thickness (m) - To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the internal and external surface resistances. This is sometimes calculated using a U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).
To determine the heat transfer between the inside and outside of a building component, it may be necessary to calculate the conductive heat transfer across a number of layers, and the internal and external surface resistances. This is sometimes calculated using a U-Value. In simple terms, the lower the U-value of an element of a building's fabric, the less heat will transmit across it. U-values are expressed in watts per square metre per degree Kelvin (W/m2K).
It is sometimes thought that conductivity is described by the U-Value, however, U-values include inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.
Conductive heat transfer is particularly high across narrow, highly conductive components such as windows. It can be inhibited by insulating materials which have a high thermal resistance. See insulation for more information. Typically conductive heat transfer is reduced by creating breaks in the continuity of a material, such as the air (or other gas) in insulation, or the air or gas filled space between the panes of glass in double or triple glazing. This breaks the conductive flow, replacing it with surface resistances and a convective heat transfer across gap.
A thermal bridge describes a situation where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope. As a result, there will be wasteful heat transfer across that element, its internal surface temperature will be different from other, better insulated areas and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth. See Thermal bridge for more information.
In practice, inside and outside temperatures do not remain constant (steady state) and the transfer of heat across a body is not instantaneous. Dynamic analysis of conductive heat transfer considers the changing temperature profiles on either side of a body and the time lag introduced by the rate of diffusion of heat through the body.
This time lag can be exploited by introducing thermal mass into the fabric of a building. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. This can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems. See Thermal mass for more information.
The amount of long wave infra-red radiation which a surface of known temperature (such as the faade of a building) will emit to its surroundings is determined by its emissivity. According to Kirchoff's law, the emissivity of a surface is equal to its radiant absorptivity at a given temperature and wavelength.
All bodies which are hotter than 0K emit thermal radiation and absorb thermal radiation. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
Thermal radiation includes all those wavelengths of the electromagnetic spectrum which will heat a body when absorbed by it, ranging from about 100 nm to 100,000 nm. In general, the higher the temperature of a body, the lower the average wavelength of the radiation it emits. The range of terrestrial temperatures experienced within the built environment is comparatively small, and relative to the temperature of the sun this range is cold and hence radiating at a much longer wavelength. This anomaly allows us to categorise thermal radiation as solar radiation and terrestrial or long wave infra-red radiation.
The wavelength of terrestrial radiation varies with temperature, however at room temperature approximately 97% of the radiation emanating from a perfect emitter will be within the range 3,000 nm to 50,000 nm. Terrestrial surfaces emit long wave infra-red radiation in all directions within a hemisphere about their azimuth.
This hemisphere can include a wide variety of thermal bodies, ranging from the clear night sky to relatively warmer solid bodies, all of which will be emitting different intensities and wavelengths of thermal radiation themselves. In order to simplify this complex situation terrestrial radiation is generally treated as an average heat transfer based on hemispherical emissivities and average hemispherical surface temperatures.
Emissivity can be an important factor in selecting building materials. For example, glass, can be given a low-e coating to reduce heat loss to the outside. In effect, this coating increases the reflectance of long wave infra-red radiation back into the interior by reducing the emissivity of the glass (its long wave infra-red absorption). Conversely, cool roofs benefit from high emissivity, re-radiating absorbed solar radiation to the sky to reduce overheating in the summer.
There is also increasing interest in the urban heat island effect, a term given to localised higher temperatures that are experienced in urban environments compared with the temperatures of surrounding green spaces. This is predominantly a factor of solar absorption, but can be reduced by high emissivity.
Introduction - Heat transfer is the process of thermal exchange between different systems. Generally the net heat transfer between two systems will be from the hotter system to the cooler system.
Heat transfer is the process of thermal exchange between different systems. Generally the net heat transfer between two systems will be from the hotter system to the cooler system.
Heat transfer is particularly important in buildings for determining the design of the building fabric, and for designing the passive and active systems necessary to deliver the required thermal conditions for the minimum consumption of resources.
Very broadly, the mechanisms of heat transfer can be described as:
Conduction. - Convection.
Convection. - Radiation.
Radiation. - Phase change.
Phase change. - The thermal behaviour of a system is a function of the dynamic relationship between these mechanisms.
The thermal behaviour of a system is a function of the dynamic relationship between these mechanisms.
Conduction - Conduction is the diffusion of internal heat within a body as a result of a temperature difference across it.
Conduction is the diffusion of internal heat within a body as a result of a temperature difference across it.
This is particularly important in buildings where there may be a temperature difference between the inside and outside of a building, such as in a heated building during winter. Conduction is one of the main potential heat transfer mechanisms by which the internal heating or cooling can be lost to the outside, resulting in high operating costs, high carbon emissions and occupant discomfort.
For building materials it is sometimes thought that conductivity is expressed by the U-Value, however, U-values are the reciprocal of the sum of the thermal resistances of a body plus its inside and outside surface thermal resistances. Conductivity is more accurately expressed by a material's R-Value, which is the reciprocal of its thermal resistance and does not include a surface component. See U-Value for more information.
Conduction can be inhibited by insulating materials which have a high thermal resistance and so help reduce heat transfer between the inside and outside. See Insulation for more information.
An insulating effect can also be achieved by the thermal mass of building components. Thermal mass describes the ability of a material to absorb, store and release heat energy. Thermal mass can be used to even out variations in internal and external conditions, absorbing heat as temperatures rise and releasing it as they fall. In building design, this can useful for evening-out and delaying extremes in thermal conditions, stabilising the internal environment and so reducing the demand for building services systems.
Convection - Convection is the movement of a fluid, such as the air, by advection and diffusion. This is a very important mechanism in the design of buildings, where air movement is necessary to:
Convection is the movement of a fluid, such as the air, by advection and diffusion. This is a very important mechanism in the design of buildings, where air movement is necessary to:
Moderate internal temperatures. - Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Reduce the accumulation of moisture, odours and other gases that can build up during occupied periods.
Improve the comfort of occupants. - Convection is also a heat transfer mechanism, resulting from the movement of air of different temperatures.
Convection is also a heat transfer mechanism, resulting from the movement of air of different temperatures.
Air movement in buildings can be 'forced' (for example driven by fans), or 'natural' resulting from pressure differences from one part of a building to another. Natural air movement can be either wind driven, or buoyancy driven. For more information see: Natural ventilation.
Accurately predicting the movement of air within buildings is extremely complicated and can require the use of computational fluid dynamics (CFD) modelling software. See CFD for more information.
See convection for more information. -
NB: Fluids can also be used to transfer heat within a building by 'mass transfer', for example by the flow of a refrigerant, chilled water or hot water around a building to provide heating or cooling.
Radiation - All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
The range of terrestrial temperatures experienced within the built environment is relatively small, and relative to the temperature of the sun this range is 'cold' and so radiating at a 'long' wavelength compared to the sun. This anomaly allows us to categorise thermal radiation as short-wave solar radiation and terrestrial or long wave infra-red radiation. Surfaces in the built environment will tend to absorb solar radiation and emit long wave infra-red radiation.
This difference also produces effects such as the greenhouse effect. The atmosphere is relatively transparent to solar radiation, this means it allows sunlight to enter the atmosphere and heat the Earth's surface. These surfaces then re-radiate that heat as long-wave infra-red radiation, which greenhouse gases tend to absorb rather than transmit. The result is that the long-wave infra-red radiation is 'trapped' and heat accumulates in the atmosphere causing a warming process. See greenhouse gases for more information.
The thermal optical properties of a material are a function of three basic parameters; transmittance, reflectance, and absorptance (or emissivity) , describing the ratio of the transmitted, radiated or absorbed radiation to the incident radiation. These properties vary depending on the wavelength and angle of the incident radiation. See Thermal optical properties for more information.
Phase change - When substances change phase, for example changing from liquid to gas, they absorb or release heat energy. For example, when water evaporates, it absorbs heat, producing a cooling effect, and when it condenses it releases heat. So when water evaporates from the surface of a building, or when sweat evaporates from the skin, it has a cooling effect.
When substances change phase, for example changing from liquid to gas, they absorb or release heat energy. For example, when water evaporates, it absorbs heat, producing a cooling effect, and when it condenses it releases heat. So when water evaporates from the surface of a building, or when sweat evaporates from the skin, it has a cooling effect.
This is also important in refrigeration, where refrigerant gases absorb heat from the cooling medium (typically water) as they evaporate, and when they condense, they release heat which is rejected to the outside (or recovered). See Refrigerants for more information.
Phase change materials can also be used in construction to reduce internal temperature changes by storing latent heat in the solid-liquid or liquid-gas phase change of a material. See Phase change materials for more information.
Radiation - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Solar radiation
2 Solar radiation - 3 Long wave infrared radiation
3 Long wave infrared radiation - 4 Greenhouse effect
4 Greenhouse effect - 5 Material properties
5 Material properties - 6 Related articles on Designing Buildings Wiki
6 Related articles on Designing Buildings Wiki - Introduction
Introduction - Radiation is a heat transfer mechanism, along with conduction, convection, phase change and mass transfer. All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
Radiation is a heat transfer mechanism, along with conduction, convection, phase change and mass transfer. All bodies which are hotter than 0K emit thermal radiation. They also absorb thermal radiation emitted by their surroundings. The difference in the total amount of radiation emitted and absorbed by a body at any given moment may result in a net heat transfer which will produce a change in the temperature of that body.
Thermal radiation includes all those wavelengths of the electromagnetic spectrum which will heat a body when absorbed by it, ranging from about 100nm to 100,000nm. In general, the higher the temperature of a body, the lower the average wavelength of the radiation it emits.
The range of terrestrial temperatures experienced within the built environment is relatively small, and relative to the temperature of the sun this range is cold and so radiating at a long wavelength compared to the sun. This anomaly allows us to categorise thermal radiation as short-wave solar radiation and terrestrial or long wave infra-red radiation.
Thermal wavelengths of the electromagnetic spectrum.jpg -
Solar radiation - Solar radiation may be considered to include the ultra violet, visible and near or short wave infra-red wavebands. Around 97% of the solar radiation incident upon the earth's surface is within the range 300 to 2,300nm. Its spectral profile is roughly analogous to that of a black body at 5762K, and as terrestrial temperatures are unlikely to reach anything like this temperature, solar radiation reaching the earth may be treated as a pure thermal gain.
Solar radiation may be considered to include the ultra violet, visible and near or short wave infra-red wavebands. Around 97% of the solar radiation incident upon the earth's surface is within the range 300 to 2,300nm. Its spectral profile is roughly analogous to that of a black body at 5762K, and as terrestrial temperatures are unlikely to reach anything like this temperature, solar radiation reaching the earth may be treated as a pure thermal gain.
Long wave infrared radiation - Most 'terrestrial' radiation occurs within the far or long wave infra-red wavebands. The wavelength of terrestrial radiation varies with temperature, however at room temperature approximately 97% of the radiation emanating from a perfect emitter will be within the range 3,000nm to 50,000nm.
Most 'terrestrial' radiation occurs within the far or long wave infra-red wavebands. The wavelength of terrestrial radiation varies with temperature, however at room temperature approximately 97% of the radiation emanating from a perfect emitter will be within the range 3,000nm to 50,000nm.
Greenhouse effect - The difference between long wave infrared radiation and short wave solar radiation produces effects such as the greenhouse effect.
The difference between long wave infrared radiation and short wave solar radiation produces effects such as the greenhouse effect.
The atmosphere is relatively transparent to solar radiation, this means it allows sunlight to enter the atmosphere and heat the Earths surface. These surfaces then re-radiate that heat as long-wave infra-red radiation, which greenhouse gases tend to absorb rather than transmit. The result is that the long-wave infra-red radiation is trapped and heat accumulates in the atmosphere causing a warming process.
See greenhouse effect for more information. -
Material properties - The way in which thermal radiation affects different materials is determined by their transmittance, reflectance and absorptance. These properties change for different wavelengths of radiation and for different angles of incidence.
The way in which thermal radiation affects different materials is determined by their transmittance, reflectance and absorptance. These properties change for different wavelengths of radiation and for different angles of incidence.
See thermal optical properties for more information. -
According to Kirchoff's law the emissivity of a surface is equal to its radiant absorptivity at a given temperature and wavelength.
See emissivity for more information. -
Solar gain in buildings - Solar gain is short wave radiation from the sun that heats a building, either directly through an opening such as a window, or indirectly through the fabric of the building. Solar design (or passive solar design) is an aspect of passive building design that focusses on maximising the use of heat energy from solar radiation.
Solar gain is short wave radiation from the sun that heats a building, either directly through an opening such as a window, or indirectly through the fabric of the building. Solar design (or passive solar design) is an aspect of passive building design that focusses on maximising the use of heat energy from solar radiation.
Solar gain is a particularly effective form of passive heating as radiation from the sun is predominately short-wave infrared radiation which is able to pass through glazing and heat the internal fabric of the building. The long-wave infrared radiation that is re-radiated by the heated fabric of the building is not able to pass back out through the glazing. This results in heat accumulating in the interior, sometimes referred to as the 'greenhouse effect'. See Thermal optical properties for more information.
Very broadly, solar gain can be beneficial in cooler climates when it can be used as a passive way of heating buildings. However, too much solar gain can cause overheating and for this reason, Part L of the UK building regulations places restrictions on the amount of glazing that can be used in buildings. Overheating as a result of solar gains can be a particular problem in warmer climates. However, the situation is complicated by the variation in conditions throughout the day and year which can mean that solar gain can be beneficial in the morning and evening, or during the winter, but can be problematic during the middle of the day or in the summer.
Relatively straight-forward design solutions such as brise soleil can be used to allow low-level winter sun to enter a building, but to shade higher, summer sun. Other solutions, such as planting deciduous trees in front of windows can be effective as leaf cover in the summer will shade glazing from solar radiation, whereas in the winter sunlight is able to pass between the bare branches and enter the building.
Passive design.jpg[Image: Passive design] -
Thermal mass in the building's interior can be used to even out variations in solar radiation, storing gains accumulated during the middle of the day and releasing them slowly, providing an ongoing heat source during cooler times of the day. An example of the use of thermal mass is a trombe wall, illustrated below.
Trombe wall.jpg[Image: Trombe wall] -
Low-e coatings on glazing can also increase the retention of solar gains by increasing the proportion of re-radiated long-wave infrared radiation that is reflected back into the interior. This effect can be enhanced at night by the use of curtains or shutters.
Maximising the benefits of solar gains can be complex and requires consideration of a wide range of issues:
Location. - Landscape.
Landscape. - Orientation.
Orientation. - Massing.
Massing. - Shading.
Shading. - Thermal mass.
Thermal mass. - Insulation.
Insulation. - Internal layout.
Internal layout. - The positioning of openings.
The positioning of openings. - The thermal optical properties of openings.
The thermal optical properties of openings. - The thermal properties of the building envelope.
The thermal properties of the building envelope. - In large or complex buildings, optimising solar gains can be require a great deal of analysis, and may involve the use of techniques such as computational fluid dynamics to model the distribution of heat through the building. Design solutions such as solar chimneys can drive the entire design of the building, its heating strategy and ventilation strategy.
In large or complex buildings, optimising solar gains can be require a great deal of analysis, and may involve the use of techniques such as computational fluid dynamics to model the distribution of heat through the building. Design solutions such as solar chimneys can drive the entire design of the building, its heating strategy and ventilation strategy.
Solar chimney.jpg[Image: Solar chimney] -
Solar heat gain can be reduced by: -
Horizontal shading. - Limiting the area of openings.
Limiting the area of openings. - Orientating openings away from the sun path.
Orientating openings away from the sun path. - Reducing solar transmittance through openings, for example by reflective glazing. This might be used in conjunction with low-e coatings that reduce the long-wave solar radiation transmitted from the outside to the inside.
Reducing solar transmittance through openings, for example by reflective glazing. This might be used in conjunction with low-e coatings that reduce the long-wave solar radiation transmitted from the outside to the inside.
Purging heat gains by the introduction of ventilation.
Insulating the building envelope to prevent the transmission of indirect solar gains.
Reducing the solar absorptance of the building envelope. The term 'albedo' relates to the total reflectance of a specific system. White coloured surfaces can be effective in minimising heat transfer into buildings.
Reducing the urban heat island effect. - Planting to provide shading and to reduce the solar absorption of roofs. See Green roofs for more information.
Planting to provide shading and to reduce the solar absorption of roofs. See Green roofs for more information.
NB: Solar radiation can also be used to provide heat to buildings through the use of solar thermal panels and solar photovoltaics.
Shading coefficient for buildings - Shading coefficients can be used to describe the amount of solar heat that passes through a transparent or translucent material compared to the amount of solar heat that passes through a sheet of clear float glass with a total solar heat gain coefficient of 0.87 (i.e. a sheet of clear float glass 3 mm thick which has a shading coefficient of 1).
Shading coefficients can be used to describe the amount of solar heat that passes through a transparent or translucent material compared to the amount of solar heat that passes through a sheet of clear float glass with a total solar heat gain coefficient of 0.87 (i.e. a sheet of clear float glass 3 mm thick which has a shading coefficient of 1).
It is typically used to describe the solar heat transmittance properties of glass, but has also been used for other translucent and transparent materials.
Solar transmittance is important for determining the solar heat gain into an enclosed space during sunny conditions. Solar heat gain can be beneficial in the winter, as it reduces the need for heating, but in the summer it can cause overheating.
The total solar heat transmittance is equal to the solar heat that is transmitted through the material directly, plus the solar heat that is absorbed by the material and then re-emitted into the enclosed space.
Shading coefficients can be measured using an illuminated hot box under simulated summer and winter conditions, and from these values, solar heat gain under a range of different conditions may be predicted using known data about solar heat gain through standard clear float glass.
This enables the behaviour of translucent or transparent materials to be predicted under different environmental conditions without having to measure the angular optical properties of every individual material.
Total shading coefficients (TSC) can be broken down into short-wave shading coefficients (SWSC) and long-wave shading coefficients (LWSC).
Manufacturers are now moving towards the use of solar heat gain coefficients (SHGC) or window solar factors (g-values) rather than shading coefficients. These represent the fraction of incident solar radiation transmitted by a window, expressed as a number between 1 and 0, where 1 indicates the maximum possible solar heat gain, and zero, no solar heat gain.
In very approximate terms, the solar heat gain coefficient is equal to the shading coefficient x 0.87.
Sustainability in building design and construction - Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (ref. Brundtland Commission, Our Common Future, 1987).
Sustainability is a broad term describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (ref. Brundtland Commission, Our Common Future, 1987).
Some broader descriptions include social and economic sustainability (which along with environmental sustainability comprise the three pillars of sustainability) although these can confuse the basic issue of the depletion of resources.
Sustainability in building developments is a vast and complex subject that must be considered from the very earliest stages as the potential environmental impacts are very significant (ref. Technology Strategy Board).
The built environment accounts for: -
45% of total UK carbon emissions (27% from domestic buildings and 18% from non-domestic).
72% of domestic emissions arise from space heating and the provision of hot water.
32% of landfill waste comes from the construction and demolition of buildings.
13% of products delivered to construction sites are sent directly to landfill without being used.
Once it has been decided to build a new building, as opposed to say changing working practices or refurbishing an existing building, a very significant commitment to consume resources has already been made. Designers and contractors may be able to help limit that consumption, but they cannot change the overall commitment.
This consumption of resources can be even more significant if the client makes a decision to relocate, with the impact this has on their staff, requiring that they either move house or change their travel plans. Decisions such as this which are often made outside of any environmental assessment process can have a far greater impact on sustainability than decisions that designers are able to influence such as the form of the building and selection of materials.
Key decisions may be picked up by an environmental impact assessment on larger projects, but even then, this can be a post-rationalisation process used to justify decisions to the local planning authority, rather than a genuine decision-making process.
Clients may wish therefore to appoint an independent client adviser with specialist knowledge of sustainability during the very early stages of their project (before the consultant team has been appointed) to help them address these high-level decisions.
Clients may have an existing environmental policy, that sets out an overall sustainability vision, as well as detailed objectives and targets. They may also have environmental accreditation such as ISO 14000 (a series of standards which provides a framework for environmental management).
Other standards may be imposed by funders, the building regulations, and planning legislation (including the possible need for an environmental impact assessment). It is wise however to write a specific environmental plan for the development being considered, as building projects involve many detailed issues that go beyond the scope of an existing corporate plan.
A project-specific environmental plan could form part of the brief, or on larger projects might be a stand-alone document. It might include an overall vision, objectives and specific targets in relation to:
Business planning: -
The need for a new building as opposed to doing nothing, refurbishment or changes in working practices.
Selection of consultants: -
Contractual requirements in relation to the selection of materials, monitoring and reporting, track record, environmental accreditation and qualifications of staff.
Selection of location: -
Availability of transport, the selection of a greenfield or brownfield site, the local availability of resources and services, the local infrastructure and local ecology.
Project brief: -
Procurement route, travel plan, working methods, standards, ecology and landscape, energy use and energy source, flexibility and durability, waste management, water management, material selection and pollution.
Design: -
Energy use and energy source, embodied energy, use of harmful materials, material sources, ecology and landscape, flexibility and durability, waste management, water management, disposal, travel plan and pollution.
Tender: -
Contractual requirements such as monitoring and reporting, working practices, track record, environmental accreditation and qualifications of staff.
Construction: -
Transport, embodied energy, use of harmful materials, material sources, working methods, site waste management plan, recycling, pollution, wheel washing, dust generation and noise nuisance.
Operation: -
Energy source, energy use, water management, maintenance, resource management, waste management, flexibility, durability, landscape and ecology, pollution, evaluation and feedback.
Resilience: -
Resilience to climate change. -
Disposal: -
Dismantling and demolition, re-use, re-sale and recycling, landscape and ecology, hazardous materials and pollution.
The environmental plan should: -
Set specific, measurable targets. - Set standards that must be adhered to.
Set standards that must be adhered to. - Establish risks and mitigation measures.
Establish risks and mitigation measures. - Establish procedures for communication and training.
Establish procedures for communication and training. - Establish procedures for monitoring and reporting.
Establish procedures for monitoring and reporting. - Establish procedures for revision and updating.
Establish procedures for revision and updating. - Environmental plans require policing, and on a large project this can be a full-time job for a specialist. At the client level, a senior champion should be appointed to take responsibility for environmental matters.
Environmental plans require policing, and on a large project this can be a full-time job for a specialist. At the client level, a senior champion should be appointed to take responsibility for environmental matters.
Predicting the likely environmental performance of a development during the design phase is becoming more important as regulations become increasing strict.
As well as the building regulations, and government targets for low carbon construction (see Low carbon construction plan), the National Planning Policy Framework makes clear that there should be a presumption in favour of granting planning permission for sustainable development, this might include low-carbon developments, and developments with resilience to climate change. This should be reflected in design and access statements for outline planning applications.
There are a number of assessment tools and standards available to help assess environmental performance:
BREEAM. - Passivhaus.
Passivhaus. - SAP the Government's Standard Assessment Procedure for energy rating of dwellings.
SAP the Government's Standard Assessment Procedure for energy rating of dwellings.
Leadership in Energy and Environmental Design (LEED), an international green building certification system.
The code for sustainable homes. - These assessment techniques are beginning to allow whole-life costing to form a fundamental part of the design process as it becomes possible to demonstrate that higher initial costs can sometimes result in lower long-term impacts and greater long-term benefits. Demonstration of actual performance in use may be necessary through requirements for a Energy Performance Certificates (EPCs) or Display Energy Certificates (DECs)
These assessment techniques are beginning to allow whole-life costing to form a fundamental part of the design process as it becomes possible to demonstrate that higher initial costs can sometimes result in lower long-term impacts and greater long-term benefits. Demonstration of actual performance in use may be necessary through requirements for a Energy Performance Certificates (EPCs) or Display Energy Certificates (DECs)
Appointments should make clear the extent and standard of environmental performance and assessment that is required.
U-values - U-value.jpg
U-value.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Typical values
2 Typical values - 3 Calculation
3 Calculation - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - 5 External references
5 External references - Introduction
Introduction - U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a building's fabric are as insulators. That is, how effective they are at preventing heat from transmitting between the inside and the outside of a building.
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a building's fabric are as insulators. That is, how effective they are at preventing heat from transmitting between the inside and the outside of a building.
R-values, which measure thermal resistance rather than thermal transmission, are often described as being the reciprocal of U-values, however, R-values do not include surface heat transfers.
The lower the U-value of an element of a building's fabric, the more slowly heat is able to transmit through it, and so the better it performs as an insulator.
Very broadly, the better (i.e. lower) the U-value of a building's fabric, the less energy is required to maintain comfortable conditions inside the building.
As energy prices increase, and there is greater awareness of sustainability, performance measures such as U-values have become more important, and building standards (such as the Building Regulations) have required that lower and lower U-values are achieved. This has required changes in the design of buildings, both in the use of materials (such as insulation), the make-up of the building elements (such as cavity walls and double glazing), and the overall make up of a building's fabric (for example, reducing the proportion of glazing).
Typical values - U-values are measured in watts per square metre per kelvin (W/(mK)). For example, a double glazed window with a U-value of 2.8, for every degree difference in temperature between the inside and outside of the window, 2.8 watts will be transmitted every square metre.
U-values are measured in watts per square metre per kelvin (W/(mK)). For example, a double glazed window with a U-value of 2.8, for every degree difference in temperature between the inside and outside of the window, 2.8 watts will be transmitted every square metre.
A range of U-values are indicated below for the purposes of comparison only:
Solid brick wall: 2 W/(mK)
Cavity wall with no insulation: 1.5 W/(mK).
Insulated wall: 0.18 W/(mK).
Single glazing: 4.8 to 5.8 W/(mK).
Double glazing: 1.2 to 3.7 W/(mK) depending on type.
Triple glazing below: 1 W/(mK).
Solid timber door: 3 W/(mK).
Part L of the Building Regulations (Conservation of fuel and power) now prevents certain forms of construction by setting limiting standards (i.e. maximum U-values) for building elements. See Limiting fabric parameters for more information.
It should be noted however that these are maximum permitted values, the specification for the notional domestic building referred to in Part L1A has considerably lower values, for example:
External wall: 0.18 W/(mK).
Floor: 0.13 W/(mK).
Roofs: 0.13 W/(mK).
Windows, roof windows, glazed rooflights and glazed doors: 1.4 W/(mK).
See Standard Assessment Procedure SAP for more information.
NB: It is important to distinguish between U-values for materials (such as glass), or assemblies (such as windows, which have frames, air gaps, and so on), or elements (such as walls, which may have complex constructions comprising a number of different components).
Calculation - The U value of an element (in W/(mK)) can be calculated from sum of the thermal resistances (R-values in mK/W) of the layers that make up the element plus its inside and outside surface thermal resistances (Ri and Ro).
The U value of an element (in W/(mK)) can be calculated from sum of the thermal resistances (R-values in mK/W) of the layers that make up the element plus its inside and outside surface thermal resistances (Ri and Ro).
U-value = 1 / (R + Ri + Ro)
Where the thermal resistance of the layers of the element R = the thickness of each layer / the thermal conductivity of that layer (its k-value or lambda value () in W/(mK)).
This can become a complicated calculation when there are a large number of layers, ventilated or unventilated cavities are introduced, or the element is inclined. Manufacturers will generally provide U-values for products that they supply. There are also a number of U-value calculators available online (such as the BRE U-value calculator, although this is not free).
Calculation methods for U-values appropriate for demonstrating compliance with the building regulations are based on standards developed by the European Committee for Standardisation (CEN) and the International Organisation for Standardisation (ISO) and published as British Standards. See Conventions for U-value calculations (2006 edition) BR 443.
Whilst U-values are still used in the Building Regulations to set limiting standards for the elements of a building's fabric, the overall thermal performance of buildings is now assessed using more complex modelling procedures.
For non-domestic buildings, the Simplified Building Energy Model (SBEM) developed by the BRE for the Department for Communities and Local Government, determines the energy performance of a proposed building by comparing its annual energy use with that of a comparable notional building. SBEM can be downloaded from the National Calculation Methodology website.
For dwellings, energy performance is assessed using the Government's Standard Assessment Procedure (SAP).
NB: Whilst U-values and methods of modelling the thermal performance of buildings are invaluable in setting standards and providing a means of comparing alternative solutions, they are simplifications of reality, and performance in use rarely matches that which was predicted. Poor workmanship can result in reduced thermal resistance, as can poor detailing and the presence of water in insulating materials. See Insulation specification and performance gap for more information.
NB: The building regulations now require that 'consequential improvements' are carried out on certain non-domestic buildings when they are extended or altered in order to bring the entire building more into line with the requirements of Part L of the Building Regulations. See Consequential improvements for more information.
Set point - In the construction industry, the term set point (or sometimes set-point or setpoint) typically refers to the point at which a building system is set to activate or deactivate.
In the construction industry, the term set point (or sometimes set-point or setpoint) typically refers to the point at which a building system is set to activate or deactivate.
For example, a heating system might be set to switch on if the internal temperature falls below 20C, an extract fan might be set to switch on if the relative humidity in a room exceeds 65% and so on.
Set points can be fixed, adjustable or variable. An adjustable set point might be controlled for example by a manually-operated thermostat. A variable set point might be controlled by some form of calculation, for example, set points for air conditioning systems may be programmed to be higher when outdoor temperatures are higher as people are more conditioned to, and dressed for those higher temperatures. Alternatively, if a building is unoccupied, the set point for the heating might be programmed to reduce to just 5C to prevent pipework from freezing.
The set point at which something is activated may be different from the set point at which it is de-activated. This prevents continually switching on and off if the conditions are very close to the set point.
Set points may be fine-tuned during the commissioning process, and building occupants may be given control of some set points, perhaps within prescribed parameters.
Set points should be monitored, and checked regularly to ensure that they are correctly set and that they are delivering the required result. Seemingly small changes in set points can have a significant impact on performance and energy use. In addition, some building spaces may house critical operations requiring very specific, closely-controlled set points.
It is important therefore that building operators and occupants are provided with an explanation of set points, their operating ranges, and the impact of adjustments on performance and energy use.
Thermostat - Smart thermostat.JPG Thermostatic radiator valve.JPG
Smart thermostat.JPG Thermostatic radiator valve.JPG - Smart thermostat Thermostatic radiator valve (TRV)
Smart thermostat Thermostatic radiator valve (TRV) - A thermostat is a component that forms part of a buildings controls, helping maintain a steady, pre-determined temperature. It does this by sensing the temperature of a system and adjusting the heating or cooling input to achieve a required set point. Thermostats are commonly used in central heating, air conditioning, HVAC system, water heaters, as well as devices such as fridges and ovens.
A thermostat is a component that forms part of a buildings controls, helping maintain a steady, pre-determined temperature. It does this by sensing the temperature of a system and adjusting the heating or cooling input to achieve a required set point. Thermostats are commonly used in central heating, air conditioning, HVAC system, water heaters, as well as devices such as fridges and ovens.
It is derived from the Greek words 'thermos' (meaning hot or heat) and 'stat' (meaning standing or stationary).
A thermostat works as a closed loop control system, which is one in which the output has an effect upon the input to maintain a desired output value. It achieves this by providing a feedback loop. For example, a boiler may have a temperature thermostat which monitors the thermal comfort level of a building and sends a feedback signal to ensure the controller maintains the set temperature.
Common types of thermostat use bimetallic strips or gas-filled bellows.
A bimetallic strip consists of two pieces of different types of metal fixed together into a strip forming a bridge in an electrical circuit connected to a heating or cooling system. As the strip changes temperature, the two metals expand or contract differentially, bending or straightening the strip slightly and eventually breaking or closing the circuit and so activating or deactivating the heating or cooling system. A drawback of bimetallic strips is that they can be relatively slow to react to changes in temperature.
Gas-filled bellows are enclosed by a pair of metal discs. The gas in the bellows expands as temperature increases, forcing the discs apart and switching off the system. This type of thermostat is typically faster to react than a bimetallic strip thermostat.
Thermostats may operate independently, or as part of a more complex system. For example, Most domestic radiators will include a thermostatic radiator valve which gives local control over the amount of hot water that is allowed into the radiator. In addition, the boiler may have controls allowing the output water temperature from the boiler to be adjusted. There is then, typically a central thermostat that allows occupants to regulate the temperature of a building or part of it as a whole.
Some thermostats may be connected to other control systems such as timer devices, or more complex Building Automation and Control Systems (BACS).
More recently, there has been an increase in the popularity of 'smart' thermostats which allow a buildings temperature to be controlled remotely using a smartphone, tablet or other device. Users can programme the thermostat to turn the heating on or off at certain times, and some models can intelligently learn about the building and how long is takes to heat up or cool down, as well as the preferences and habits of the occupants. This can help use energy more efficiently
Tap - Tap cat pixabay 640.jpg
Tap cat pixabay 640.jpg - A typical mixer tap with separate hot- and cold-water controls.
A typical mixer tap with separate hot- and cold-water controls.
Introduction - A tap is a valve that is used to control the flow of liquid (or gas) exiting a supply source. It is an opening and closing device that allows the required amount ofl, for example water, to flow out of a supply system. In the USA, taps are called faucets.
A tap is a valve that is used to control the flow of liquid (or gas) exiting a supply source. It is an opening and closing device that allows the required amount ofl, for example water, to flow out of a supply system. In the USA, taps are called faucets.
Taps can be used to control various liquids and gases, such as water, oil and natural gas. Opening and closing is usually achieved by a rotation of a lever or handle, whether by numerous turns or by a quarter turn. In a laboratory setting, taps will usually be referred to as gas taps. Traditional domestic cookers also had gas taps.
Types of domestic water tap - Numerous types of water tap may be seen in homes:
Numerous types of water tap may be seen in homes:
Rising spindle tap this is the traditional design featuring a spindle and washer that can move up and down when the handle is turned. Bib taps are an example and are typically fixed to say, an external wall for watering purposes. They may also be the main stop-cock (tap) that regulates water flow into the dwelling.
Non-rising head taps feature a non-revolving spindle with a handle which traditionally has been made of clear plastic.
Ceramic disc taps have precision-ground, rotating ceramic discs in place of a washer.
Pillar taps in the kitchen or bathroom, the tap is mounted on the end of a stub post; there may be one for hot water and another for cold water.
Mixer taps seen in the kitchen and bathroom, these have become very popular in recent years. They can mix the water, i.e combine the hot and cold water flows out through a common spout to provide water at the required temperature. Mixer taps can be operated by a single lever which regulates both the flow and the temperature, according to the position it is set to. Or they can have two separate hot and cold taps that convey the water through a common spout.
Most domestic taps are available in a variety of finishes, including satin chrome-plated, stainless steel or enamelled brass.
BSRIA (Building Services Research and Information Association) define Building Performance Evaluation (BPE) as:
a form of Post-Occupancy Evaluation (POE) which can be used at any point in a building's life to assess energy performance, occupant comfort and make comparisons with design targets.
Building Performance Evaluations are an integral part of a soft landings programme, a strategy adopted to ensure the transition from construction to occupation is bump-free and that operational performance is optimised. Soft landings keeps designers and constructors involved with buildings beyond practical completion.
As clients increasingly demand proof of performance, BPE is becoming a requirement on many projects, particularly in the public sector for schools, offices and healthcare buildings. Services can range from a complete evaluation to providing energy monitoring instruments and benchmarking building performance.
BPE generally falls into three elements: -
A forensic walkthrough; an inspection to check the building's operation and whether there are any emerging problems or wasteful operational practices.
An energy survey; a breakdown of the energy used in a building by type of consumption, for example, heating, air conditioning, and so on.
Assessment of occupant satisfaction; surveys and interviews of building users and occupiers.
For more information, download BSRIA's introduction to BPE presentation on behalf of the Modern Built Environment KTN for more details.
In September 2015, BSRIA launched Building Performance Evaluation in Non-Domestic Buildings Guide an introduction to the tests and methods in non-domestic buildings. The guide provides a general introduction to Building Performance Evaluation (BPE) and explains why it is important and how it can be carried out. BPE is a key element of the BSRIA soft landings framework intended to help deliver buildings that are an effective and efficient and perform as expected. The guide focuses on new, existing and refurbished non-domestic buildings and aims to inform those involved in the design, construction, operation and/or management of a building about its current performance.
Energy consumption in the construction industry - Dynamic-response-to-energy280.jpg
Dynamic-response-to-energy280.jpg -
In very general terms, energy is a capacity to do work that can take a number of different forms, such as; thermal (heat), radiant (light), motion (kinetic), stored (potential), secondary (e.g. electricity), chemical, mechanical, and so on.
The term 'energy consumption' refers to the amount of energy that is used by a process, system, product, community and so on.
In the built environment, the term 'energy' is typically used in the context of generating heat, powering equipment, creating products and materials, transportation, and so on.
In a domestic context, energy consumption is often attributed to:
Heating. - Hot water.
Hot water. - Cooling and refrigeration.
Cooling and refrigeration. - Lighting.
Lighting. - Washing and drying.
Washing and drying. - Cooking.
Cooking. - Other electric loads.
Other electric loads. - Sources of energy tend to be categorised as either renewable or non-renewable.
Sources of energy tend to be categorised as either renewable or non-renewable.
For more information see: Energy. -
The total energy consumed by end users is typically referred to as final energy consumption. This is a measure of the energy that is used by the consumer and does not include that used by the sector itself in extraction, delivery, transformation, and so on.
Per capita energy consumption varies to a great extent between countries. At a rough estimate, wealthy developed countries consume 10-20 times as much energy per capita as poorer developing countries. However, energy consumption in many developing regions is rising rapidly.
The energy consumption of buildings, and the role of the construction industry to minimise it, has been a focus of government significant policy change and legislation such as; the Climate Change Act, Carbon Plan, Infrastructure Act, Building Regulations and Construction 2025. Several initiatives and devices, such as the use of smart meters and energy performance certificates, Green Deal, Energy Company Obligation, low-enery lightbulbs, door and window energy rating, and so on have been introduced in an attempt to reduce the energy consumption of buildings.
The energy consumed by a building throughout its whole life comprises:
Initial embodied energy. The energy consumed to create the building, including; extraction, processing and manufacture, transportation and assembly.
Recurring embodied energy. That is the energy consumed in refurbishing and maintaining the building during its life.
Operational energy. The energy consumed in heating, cooling, lighting and powering appliances in the building.
Demolition energy: The energy consumed in the disposal of the building.
For more information see: Embodied energy. -
Energy efficiency not only allows individuals and organisations to reduce their capital and operational costs, is can also help lower fuel consumption and so reduce the emission of greenhouse gases and help prevent climate change.
For more information see: Energy efficiency. -
NB The Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018 defines energy demand as:
'The building energy provided for end uses in the building such as space heating, hot water, space cooling, lighting, fan power and pump power. Energy demands are the same as room loads. One of the outputs from the Building Regulations Output Document is for heating and cooling energy demand only, not for any other building energy uses. Heating and cooling energy demands are influenced by factors including building fabric heat loss, air permeability, glazing and shading.'
Carbon emissions in the built environment - Carbon-capture-and-storage.jpg
Carbon-capture-and-storage.jpg -
The term carbon emissions refers to the release into the atmosphere of carbon dioxide (CO2).
Carbon dioxide is a naturally-occurring colourless and odourless gas that is integral to life. It is also a greenhouse gas and the burning of carbon-based fossil fuels means there is more carbon carbon dioxide in the atmosphere leading to increased rates of climate change.
Carbon-based fuels that release carbon dioxide when burned include timber, coal, gas, oil, petrol, diesel and so on.
The amount of carbon released by a particular event, person, building or thing is typically referred to as its carbon footprint, and is measured in tonnes of CO2. On a individual level, the main contributors to a carbon footprint include the amount of type of energy that is used to heat the home, the use of electrical appliances, type of transport, amount of air travel, and so on.
The Building Regulations set out requirements for specific aspects of building design and construction. Regulation 26 of the building regulations states that 'where a building is erected, it shall not exceed the target CO2 emission rate for the building'.
The target CO2 emission rate (TER) sets a minimum allowable standard for the energy performance of a building and is defined by the annual CO2 emissions of a notional building of same type, size and shape to the proposed building. TER is expressed in annual kg of CO2 per sq. m.
Energy performance certificates (EPCs), set out the energy efficiency rating of buildings. They are required when buildings are built, sold or rented, if they have a roof and walls and use energy to condition an indoor climate.
The establishment of the Climate Change Act 2008 committed the UK to reducing greenhouse gases by at least 80% by 2050 (compared to the 1990 baseline), with a reduction of at least 34% by 2020. A strategy for how this was to be achieved was set out in The Carbon Plan published in December 2011.
The commitment to reducing carbon emissions is a considerable, and often controversial, factor in the development of major infrastructure projects such as the third runway at Heathrow Airport, with activists arguing that its construction will tie the UK into an increased rate of emissions for many years.
In December 2006, the then Labour government committed that from 2016 all new homes would be zero carbon and introduced the Code for Sustainable Homes, against which the sustainability of new homes could be rated. However, on 10 July 2015, the government published Fixing the foundations: creating a more prosperous nation which made the surprising decision to scrap the zero carbon homes initiative.
Environmental impact - Environment Agency water image.png
Environment Agency water image.png -
The term environmental impact refers to the possible effects a particular action may have on the natural environment. These effects can be either negative or positive.
According to the UK Green Building Council (UKGBC), the construction sector uses more than 400 million tons of material each year, much of which has a negative environmental impact. In particular, the products that are used during the construction process can be damaging due to intensive extraction of raw materials, transporting to manufacturing plant and site, energy consumption in manufacture and in use, waste generation and so on.
In addition, the Environmental Protection Agency (EPA) has highlighted the significant change in the surface of a land due to construction activity which involves clearing vegetation, excavation, disrupting habitats, changes to drainage patterns and the water table, noise pollution, light pollution, dust, vibration and so on.
The Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 2011 sets out a requirement to carry out an environmental impact assessment (EIA) as part of the planning application process for certain projects (generally large or environmentally complex projects).
The purpose of an EIA is to ensure that the environmental effects of a proposed development are properly considered. An EIA provides the local planning authority with better information about certain types of project enabling them to make a more informed decision about whether permission should be granted and to allow imposition of more appropriate conditions and obligations to mitigate possible negative impacts.
Ecological Impact Assessments are a key part of EIAs. These identify, quantify and evaluate the potential impacts of on ecosystems or their components.
For more information see: Environmental impact assessment.
A construction environmental management plan may be developed, outlining how a construction project will avoid, minimise or mitigate impact on the environment and surrounding area.
Building envelope - Copper cladding.jpg
Copper cladding.jpg -
According to Approved Document L2B: conservation of fuel and power in existing buildings other than dwellings, the term 'building envelope' refers to:
...the walls, floor, roof, windows, doors, roof windows and roof lights.
Together, these form the physical separation between the interior and exterior, that is, the climatic modifier that creates and contains the internal conditions.
The nature of the building envelope is likely to depend on a wide range of requirements, some of which may be in conflict:
The type of building. - Its location and context.
Its location and context. - Its form.
Its form. - Regulatory requirements.
Regulatory requirements. - Local climatic conditions.
Local climatic conditions. - The internal conditions required.
The internal conditions required. - The need for openings, views, security, safety, access, privacy and so on.
The need for openings, views, security, safety, access, privacy and so on.
Available materials. - Structural requirements.
Structural requirements. - Building services strategy,
Building services strategy, - Sustainability requirements.
Sustainability requirements. - Maintenance and cleaning requirements.
Maintenance and cleaning requirements. - Rainwater run off.
Rainwater run off. - Durability, flexibility and expected life.
Durability, flexibility and expected life. - The method of construction, deconstructability and recyclability.
The method of construction, deconstructability and recyclability.
Stylistic requirements. - Budgetary and time constraints.
Budgetary and time constraints. - NB According to Approved Document L1A:
NB According to Approved Document L1A: -
The envelope area of a terraced house includes the party wall(s). The envelope area of a flat in a mulit-storey building includes the floors, walls and ceilings which are shared with adjacent flats.
And, in relation to air permeability: -
The envelope area, or measured part of the building, is the total area of all floors, walls and ceilings bordering the internal volume that is the subject of the pressure test. This includes walls and floors below external ground level. Overall internal dimensions are used to calculate this envelope area and no subtractions are made for the area of the junctions of internal walls, floors and ceilings with exterior walls, floors and ceilings.
National Calculation Methodology (NCM) modelling guide (for buildings other than dwellings in England) 2013 edition, published by the Department for Communities and Local Government (DCLG), defines envelope area as:
Area of vertical envelopes (walls) = h * w, where:
h = floor to floor height, ie including floor void, ceiling void and floor slab. For top floors, h is the height from floor to the average height of the structural ceiling.
w = horizontal dimension of wall. Limits for that horizontal dimension are defined by type of adjacent walls. If the adjacent wall is external, the limit will be the internal side of the adjacent wall. If the adjacent wall is internal, the limit will be half-way through its thickness.
NB: Areas of floor, ceilings, and flat roofs are calculated in the same manner as the zone area. Area for an exposed pitched roof (i.e., without an internal horizontal ceiling) will be the inner pitched surface area of the roof.
Energy Efficiency and Historic Buildings, How to Improve Energy Efficiency, Published by Historic England in 2018, defines the building envelope as:
The weathertight skin separating the interior of a building from its external environment. It is made up of the roof, walls, windows, doors, floors and foundations; and systems for controlling and disposing of water, including rainwater goods, roof coverings, damp-proof courses and drains).
Compression - Contents
Contents - [hide]
[hide] - 1 Simple compression
1 Simple compression - 2 Strength of materials
2 Strength of materials - 3 Buckling
3 Buckling - 4 Compressive structures
4 Compressive structures - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - Simple compression
Simple compression - Simple compression occurs when the particles of a material are pushed against each other. As a state of stress, it is the opposite of tension, where particles are pulled apart.
Simple compression occurs when the particles of a material are pushed against each other. As a state of stress, it is the opposite of tension, where particles are pulled apart.
When a column supports a load (or weight) from above, it is said to be under compressive stress; it also shortens a typical consequence of compression. The same applies to a strut in a truss or bridge which is designed to work solely in compression.
Compressive shortening is proportional to the load per unit area (of a column) and is typical of compression, just as lengthening is typical of tension. In addition to the compressive shortening which takes place along the longitudinal axis (usually the centre line), there is also lengthening that occurs at right angles to the longitudinal axis. In other words, the column gets shorter and fatter.
Strictly speaking, a compression member such as a column or strut is subject only to axial compressive forces ie the load is applied through the members centre and along the longitudinal axis. The stress in the compressed member is given by the load over the cross-sectional area.
Simple compression is a common phenomenon in building structures as all loads and forces have eventually to be directed into the ground. Thus, they occur in Greek temples as much as in Manhattan skyscrapers.
Strength of materials - Concrete, masonry are materials with high compressive strengths but they are also weak in resisting tension. Steel has a high compressive strength and also a high tensile strength and can resist the same compressive forces as concrete or masonry but with a slimmer profile.
Concrete, masonry are materials with high compressive strengths but they are also weak in resisting tension. Steel has a high compressive strength and also a high tensile strength and can resist the same compressive forces as concrete or masonry but with a slimmer profile.
Buckling - When a material has sufficient compressive strength to allow the use of smaller cross-sections, the result may be lower costs but this could have side effects. Increasing the slenderness ratio (the column length is many times greater compared to the cross-sectional area), may lead to buckling. If the load is great combined with a relatively small cross-sectional area, the column may buckle as it is easier for it to bend outwards (or buckle), rather than shorten. Buckling may also be exacerbated by eccentric loads.
When a material has sufficient compressive strength to allow the use of smaller cross-sections, the result may be lower costs but this could have side effects. Increasing the slenderness ratio (the column length is many times greater compared to the cross-sectional area), may lead to buckling. If the load is great combined with a relatively small cross-sectional area, the column may buckle as it is easier for it to bend outwards (or buckle), rather than shorten. Buckling may also be exacerbated by eccentric loads.
Whether a column reaches its buckling load limit will depend on numerous factors, including its length, the type of material, the cross-sectional shape and how it is restrained at its ends.
Compressive structures - Being built mostly from masonry, Greek and Roman temples, and Romanesque and Gothic cathedrals, are structures almost entirely under compression.
Being built mostly from masonry, Greek and Roman temples, and Romanesque and Gothic cathedrals, are structures almost entirely under compression.
An arch in brickwork or stonework has simple, uniform compression and no bending (and therefore little or no tension). The thrust of the arch compressive forces diverging down and either side of the keystone is absorbed by the abutments on either side. For more information see: Arch
The flying buttress in a Gothic cathedral channels forces of compression from the roof and walls down into the foundations. For more information see: Flying buttress
When under load, a dome develops compressive stresses along its meridians; these can be thought of as an infinite number of arches connecting opposite points on the ground circumference. The dome will also develop compressive or tensile stresses around its hoops (lines of latitude).
Steel - Steel is an alloy of iron and a number of other elements, mainly carbon, that has a high tensile strength and relatively low cost.
Steel is an alloy of iron and a number of other elements, mainly carbon, that has a high tensile strength and relatively low cost.
Early forms of steel have existed since around 1800 BC, and it has subsequently be used through history by the Greeks, Romans, Indians and Chinese. However, British engineer, Sir Henry Bessemer was the first to develop a cost-efficient method for producing steel, and it was first mass produced for the manufacture of railway tracks.
There is an excellent, free-to-use, online encyclopedia for UK steel construction available at SteelConstruction.info.
Steel construction info.jpg -
SteelConstruction.info was created and is maintained by Tata Steel, the British Constructional Steelwork Association (BCSA) and the Steel Construction Institute (SCI).
The site contains more than 100 articles written by experts on subjects including:
Cost planning. - Life cycle assessment.
Life cycle assessment. - Steel infographic.
Steel infographic. - Sustainability.
Sustainability. - Corrosion.
Corrosion. - Construction.
Construction. - Fire engineering.
Fire engineering. - Design.
Design. - Links to more detailed resources.
Links to more detailed resources. - Acoustics.
Acoustics. - Floor vibrations.
Floor vibrations. - Health and safety.
Health and safety. - Fabrication.
Fabrication. -
Damp proofing buildings - The term damp proofing refers to types of moisture control that are applied to walls and floors to prevent damp from setting in or spreading in a building.
The term damp proofing refers to types of moisture control that are applied to walls and floors to prevent damp from setting in or spreading in a building.
Damp problems are among the most frequent problems encountered in buildings, particularly older buildings which may have been constructed without a damp-proof membrane.
Damp may be apparent from: -
Damp patches. - Mould growth.
Mould growth. - Mildew, salts, staining and 'tide marks'.
Mildew, salts, staining and 'tide marks'.
Damage to surface finishes, such as blistering paint and bulging plaster.
Corrosion and decay of the building fabric. - Slip hazards.
Slip hazards. - Frost damage.
Frost damage. - Poor performance of insulation.
Poor performance of insulation. - Damage to equipment, or electrical failure.
Damage to equipment, or electrical failure. - The most common causes of persistent damp in buildings are:
The most common causes of persistent damp in buildings are:
Condensation (surface or interstitial). - Rising damp.
Rising damp. - Penetrating damp.
Penetrating damp. - The two most common damp proofing techniques are:
The two most common damp proofing techniques are:
Installation of a damp-proof course. A damp-proof course is a barrier, usually formed by a membrane built into the walls of a property, typically 150 mm above ground level, to prevent damp rising through the walls. Damp-proof courses are now required in the construction of new buildings to prevent rising damp and in some situations to prevent penetrating damp.
Damp proof courses can also be retrofitted to existing buildings by the injection of water-repellent chemicals. Treatment generally also involves remedial work to any corroded or decayed elements of the building fabric, as well as hacking off and replacing existing plaster to a height of 1 m.
For more information, see Damp proof course.
Installation of a damp-proof membrane (DPM). Typically, a DPM is a polyethylene sheet laid under a concrete slab to prevent the concrete from transmitting moisture through capillary action.
For more information, see Damp proof membrane.
Other damp proofing techniques include: -
Integral damp proofing: Concrete production can involve the addition of materials to make it more impermeable.
Surface coating: Waterproof surface materials can be used internally or externally, such as render or waterproof plaster.
Cavity wall systems: A cavity separates the interior walls from the exterior walls.
Pressure grouting: This can fill in cracks and joints in masonry.
Colourless water-repellent treatments. - However, it is important to note that damp is often just a symptom of another problem in a building, such as a lack of ventilation, drainage problems, cracks in walls, missing tiles or leaking pipework. It is important therefore that the underlying problem is rectified before other treatments are applied.
However, it is important to note that damp is often just a symptom of another problem in a building, such as a lack of ventilation, drainage problems, cracks in walls, missing tiles or leaking pipework. It is important therefore that the underlying problem is rectified before other treatments are applied.
Plaster - Plastering.jpg
Plastering.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 History of plastering
2 History of plastering - 3 Types of plaster by binder
3 Types of plaster by binder - 3.1 Gypsum plaster
3.1 Gypsum plaster - 3.2 Lime plaster
3.2 Lime plaster - 3.3 Cement plaster
3.3 Cement plaster - 3.4 Clay plaster
3.4 Clay plaster - 4 Types of plaster by application
4 Types of plaster by application - 5 Plastering techniques
5 Plastering techniques - 6 Related articles on Designing Buildings Wiki
6 Related articles on Designing Buildings Wiki - Introduction
Introduction - Plaster is a building material used for coating, protecting and decorating internal walls and ceilings. It can also be used to create architectural mouldings such as ceiling roses, cornices, corbels, and so on.
Plaster is a building material used for coating, protecting and decorating internal walls and ceilings. It can also be used to create architectural mouldings such as ceiling roses, cornices, corbels, and so on.
The most common types of plaster are a composition of gypsum, lime or cement with water and sand. The plaster is typically manufactured as a dry powder and then worked to form a stiff paste by mixing in water before application.
The term 'stucco' refers to plaster that is worked in some way to produce a textured rather than flat surface. See Stucco for more information.
Render is similar to plaster, but is applied to the outside of buildings and has waterproofing properties. See Rendering for more information.
History of plastering - A form of plastering was used by primitive civilisations, creating durable and weather-resistant structures using mud. The Egyptian pyramids contain plasterwork comparable to that used today that remains hard and durable some 4,000 years later.
A form of plastering was used by primitive civilisations, creating durable and weather-resistant structures using mud. The Egyptian pyramids contain plasterwork comparable to that used today that remains hard and durable some 4,000 years later.
Greek artisans used plaster, mainly to cover the exterior of temples but sometimes also interiors. Through history, plaster ceilings became increasingly ornamental, with those during the Tudor period being particularly extravagant.
However, the use of plaster as a means of demonstrating artistic skill and expression had waned by the 19th century, when imitation and mechanical reproduction displaced it as a creative medium. However, plaster is still very commonly used as a surface finish for interior walls, ceilings, and still sometimes for exterior walls.
Types of plaster by binder - There are a number of different types of plaster, depending on the binder that is used.
There are a number of different types of plaster, depending on the binder that is used.
Gypsum plaster - Gypsum plaster, or plaster of Paris (POP), is the most common form of plaster for interior walls. It is produced by heating gypsum to around 150C (300 F). When mixed with water, the dry plaster powder re-forms into gypsum. Unmodified plaster starts to set about 10 minutes after mixing, but it will not be fully set until 72 hours have elapsed. Gypsum plaster has good fire-resistant qualities.
Gypsum plaster, or plaster of Paris (POP), is the most common form of plaster for interior walls. It is produced by heating gypsum to around 150C (300 F). When mixed with water, the dry plaster powder re-forms into gypsum. Unmodified plaster starts to set about 10 minutes after mixing, but it will not be fully set until 72 hours have elapsed. Gypsum plaster has good fire-resistant qualities.
Lime plaster - Lime plaster is a composite of calcium hydroxide (lime) and sand (or other inert fillers). It may sometimes be strengthened with animal hair to preventing cracking and reduce shrinkage. The plaster sets through contact with carbon dioxide in the atmosphere which transforms the calcium hydroxide into calcium carbonate (limestone). It is typically more flexible and breathable than gypsum and cement plasters, and is most commonly used on older properties.
Lime plaster is a composite of calcium hydroxide (lime) and sand (or other inert fillers). It may sometimes be strengthened with animal hair to preventing cracking and reduce shrinkage. The plaster sets through contact with carbon dioxide in the atmosphere which transforms the calcium hydroxide into calcium carbonate (limestone). It is typically more flexible and breathable than gypsum and cement plasters, and is most commonly used on older properties.
Cement plaster - Cement plaster is a mixture of sand, cement and water. It is normally applied to masonry interiors and exteriors. While it is capable of achieving a smooth surface, interiors will sometimes require an additional finishing layer of gypsum plaster. Cement plaster offers greater moisture resistance than gypsum plaster.
Cement plaster is a mixture of sand, cement and water. It is normally applied to masonry interiors and exteriors. While it is capable of achieving a smooth surface, interiors will sometimes require an additional finishing layer of gypsum plaster. Cement plaster offers greater moisture resistance than gypsum plaster.
Clay plaster - Clay plaster is considered to be a more sustainable alternative to modern plasters, with a lower embodied energy than gypsum, cement or lime based plasters. It is available with fibre additives to increase its strength, and in a range of natural colours. It is breathable and does not need to be painted.
Clay plaster is considered to be a more sustainable alternative to modern plasters, with a lower embodied energy than gypsum, cement or lime based plasters. It is available with fibre additives to increase its strength, and in a range of natural colours. It is breathable and does not need to be painted.
Types of plaster by application - Plasters can also be categorised by application:
Plasters can also be categorised by application: -
Board finish plaster is used on plasterboard. - Bonding plaster is used as an undercoat, applied to new walls.
Bonding plaster is used as an undercoat, applied to new walls.
Browning plaster is used as an undercoat for particularly absorbent surfaces.
Dri-coat plaster offers moisture resistance for walls that have had a damp proof course (DPC) inserted or injected.
Hardwall plaster is similar to browning plaster, but is faster drying and has better impact resistance.
Heat resistant plaster is used for walls and chimney breasts where temperatures may exceed 50C.
Multi-finish plaster is a top coat plaster. - One-coat plaster is typically used as a patching plaster.
One-coat plaster is typically used as a patching plaster.
Tough coat plaster has exceptional impact resistance. - Plastering techniques
Plastering techniques - Plaster is typically built up in layers, with the number of layers depending on the roughness of the surface being plastered. Rough, bare walls could require three coats of plaster, while plasterboard might just require a finishing skim of 2 to 3mm.
Plaster is typically built up in layers, with the number of layers depending on the roughness of the surface being plastered. Rough, bare walls could require three coats of plaster, while plasterboard might just require a finishing skim of 2 to 3mm.
The plaster compound, which is typically supplied dry, must first be mixed with water, with care being taken to achieve the correct creamy consistency. Mixing is best achieved by adding the plaster to the water, not the other way round.
The plaster can then be applied to the wall. The first coat is applied, scratched and left to dry. This is followed by the second coat and finally a third finishing layer.
Plastering is a labour intensive and time-consuming process and as a result it has gone into something of a decline in recent years, with techniques such as dry lining gaining in popularity.
While plaster is durable, it can be prone to cracking if the building experiences settlement or if it has been applied incorrectly.
Heating degree days - Heating degree days (HDD) are used to give an indication of the effect of outside air temperature on building energy consumption during a specified period of time. They represent the number of degrees and number of days that the outside air temperature at a specific location is lower than a specified base temperature (or balance point). This gives an indication of how much heating will be required in the building.
Heating degree days (HDD) are used to give an indication of the effect of outside air temperature on building energy consumption during a specified period of time. They represent the number of degrees and number of days that the outside air temperature at a specific location is lower than a specified base temperature (or balance point). This gives an indication of how much heating will be required in the building.
The base temperature of a building is the temperature below which it needs heating, which will depend on the building type and use.
So for example, if the base temperature of a building is 21 degrees, and the outside air temperature is 12 degrees for eight hours (one third of a day), then that represents 3 heating degree days ((21-12) x 1/3 = 3).
Adding up heating degree days can give a weekly, monthly or annual figure.
Heating degree days calculated for locations with publicly available meteorological data and so it is necessary to locate an accurate weather station, with good historical data close to the site being investigated, or in circumstances similar to the site being investigated. Weather station data such as that available from airports is often considered to be the highest quality.
Websites such as Degree Days Net can be used to calculate heating degree days for a given location and base temperature.
Data is also available to allow calculation of cooling degree days representing the number of degrees and days the outside temperature is above the base temperature and growing degree days, based on the temperature range within which plants will grow.
Heating and cooling degree days can be used to help assess or compare different potential sites for development. They can also be used as a way of normalising weather between different sites, allowing comparison of the performance of different buildings, or for normalising weather between different years to assess changes in the performance of a building.
However, despite being a very simple concept, they are difficult to use effectively in practice, and do not always provide an effective way of influencing design decisions.
There can be difficulty separating out heating and cooling energy consumption from overall energy consumption, and heating and cooling requirements are influenced by other factors such as; other heat sources (including people, lighting, equipment and solar gain), thermal mass, thermal insulation and so on. In addition, heating and cooling inputs tend to be intermittent rather than continuous, and buildings are not necessarily always occupied.
It is possible to take account of these matters in calculations and through the use of sub-metering, but this can become a very complicated process, based on a deceptively simple indicator. The use of degree days should therefore be treated with caution, employed as part of a broader process of analysis and assessment providing only a general indicator for order of magnitude assessments rather than accurate detailed comparisons.
Cooling degree days - Cooling degree days (CDD) are used to give an indication of the effect of outside air temperature on building energy consumption during a specified period of time. They represent the number of degrees and number of days that the outside air temperature at a specific location is higher than a specified base temperature (or balance point). This gives an indication of how much cooling will be required in the building.
Cooling degree days (CDD) are used to give an indication of the effect of outside air temperature on building energy consumption during a specified period of time. They represent the number of degrees and number of days that the outside air temperature at a specific location is higher than a specified base temperature (or balance point). This gives an indication of how much cooling will be required in the building.
The base temperature of a building is the temperature above which it needs cooling, which will depend on the building type and use.
So for example, if the base temperature is 21 degrees, and the outside air temperature is 30 degrees for eight hours (one third of a day), then that represents 3 cooling degree days ((30-21) x 1/3 = 3).
Adding up the cooling degree days can give a weekly, monthly or annual figure.
Cooling degree days can be found for locations with publicly available meteorological data and so it is necessary to locate an accurate weather station, with good historical data close to the site being investigated, or in circumstances similar to the site being investigated. Weather station data such as that available from airports is often considered to be the highest quality.
Websites such as Degree Days Net can be used to calculate cooling degree days for a given location and base temperature.
Data is also available to allow calculation of heating degree days representing the number of degrees and days the outside temperature is below the base temperature and growing degree days, based on the temperature range within which plants will grow.
Heating and cooling degree days can be used to help assess or compare different potential sites for development. They can also be used as a way of normalising weather between different sites, allowing comparison of the performance of different buildings, or for normalising weather between different years to assess the change in performance of a building.
However, despite being a very simple concept, they are difficult to use effectively in practice, and do not always provide an effective way of influencing design decisions. There can be difficulty separating out heating and cooling energy consumption from overall energy consumption, and heating and cooling requirements are influenced by other factors such as; other heat sources (including people, lighting, equipment and solar gain), thermal mass, thermal insulation and so on. In addition, heating and cooling inputs tend to be intermittent rather than continuous, and buildings are not necessarily always occupied.
It is possible to take account of these matters in calculations and through the use of sub-metering, but this can become a very complicated process, based on a deceptively simple indicator. The use of degree days should be treated with caution as part of a broader process of analysis, providing a general indicator for order of magnitude assessments rather than for accurate, detailed comparisons.
Landscape urbanism - Highline.jpg
Highline.jpg -
Landscape urbanism is the theory of urban planning through the medium of landscape. It promotes the general idea that cities are best planned and organised, not through building and infrastructure design, but through the design of landscape.
Since emerging in the mid-1990s, landscape urbanism has taken several different forms and interpretations. It was popularised by American landscape architects who used the term to refer to the reorganisation and planning of post-industrial cities such as Detroit and others that were in decline. By the late-2000s, the term had come to be used in reference to high-profile projects of urban renewal, often with commercial investment, such as London's Olympic Park.
Other projects that are seen as being influenced by landscape urbanism include; the High Line in New York, Millennium Park in Chicago, the Olympic Sculpture Park in Seattle, and Parc de la Villette in Paris.
As a theory, landscape urbanism originated in the late-1980s, when landscape architects and urbanists such as Peter Connolly, Richard Weller and Charles Waldheim began to explore the perceived boundaries and limits of their respective disciplines within the context of complex urban projects. The first Landscape Urbanism conference was held in Chicago in 1997, following which, academic programmes in America and Europe began to formalise the emerging practice in institutions such as the University of Toronto, Harvard Graduate School of Design, Massachusetts Institute of Technology, and Oslo School of Architecture.
These theorists sought to 'claim landscape as urbanism' and viewed the concept as a reaction to 'architecture and urban design's inability to offer coherent and convincing accounts of contemporary urban conditions'.
In essence, the theory suggests that landscape should supplant architecture from its traditional role as the foundation for urban form. In terms of a project this may be achieved through managing infrastructure, water, biodiversity and human activity, and examining the ecological and environmental implications of the urban development.
One of the leading theorists, James Corner, suggested the most important ideas for landscape urbanism are:
Process over time: Ecological awareness with regard to the built environment.
Horizontality: Horizontal alignment in landscapes, as opposed to vertical structuring.
Working methods/techniques: Techniques should be adapted to the relevant environment.
Imaginary: The failure of 20th century planning is a result of 'the absolute impoverishment of the imagination to extend new relationships and sets of possibilities.'
Critics of landscape urbanism point to its stubborn resistance to clarity in terms of a common methodology or even an easy definition. It is argued that it remains an abstract academic theory that uses obscurantist post-modern language with few actual built examples to draw from.
Environment - Thermal comfort.jpg
Thermal comfort.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 The natural environment
2 The natural environment - 3 The built environment
3 The built environment - 4 Personal environmental conditions
4 Personal environmental conditions - 5 Other classifications
5 Other classifications - 6 Business definition
6 Business definition - 7 Related articles on Designing Buildings Wiki
7 Related articles on Designing Buildings Wiki - Introduction
Introduction - In its broadest sense, the term environment refers to all of the things around us. These things can affect our comfort, wellbeing, performance, behaviour, growth and development. In turn, our behaviour can impact on the environment around us.
In its broadest sense, the term environment refers to all of the things around us. These things can affect our comfort, wellbeing, performance, behaviour, growth and development. In turn, our behaviour can impact on the environment around us.
In a very general way, the environment can be considered to comprise:
The natural environment. - The built environment.
The built environment. - The natural environment
The natural environment - The term 'natural environment' refers to the non-human-made surroundings and conditions in which all living and non-living things exist. The common concept of the natural environment encompasses two different components:
The term 'natural environment' refers to the non-human-made surroundings and conditions in which all living and non-living things exist. The common concept of the natural environment encompasses two different components:
Ecological units that operate as natural systems (such as soil, vegetation and so on).
Universal natural resources (such as air and water).
In this sense, the term environmental has become synonymous with sustainability describing a desire to carry out activities without depleting resources or having harmful impacts, defined by the Brundtland Commission as 'meeting the needs of the present without compromising the ability of future generations to meet their own needs.' (ref. Brundtland Commission, Our Common Future, 1987).
For more information see: Natural environment. -
The built environment - The term built environment refers to aspects of our surroundings that are built by humans. It includes not only buildings, but the human-made spaces between buildings, such as parks, and the infrastructure that supports human activity such as transportation networks, utilities networks, flood defences, telecommunications, and so on.
The term built environment refers to aspects of our surroundings that are built by humans. It includes not only buildings, but the human-made spaces between buildings, such as parks, and the infrastructure that supports human activity such as transportation networks, utilities networks, flood defences, telecommunications, and so on.
The built environment is increasingly developed in a way that considers both its resilience to and its impact on the natural environment.
For more information see: Built environment. -
Personal environmental conditions - The way that individuals experience the environment around them comprises a number of different characteristics, including:
The way that individuals experience the environment around them comprises a number of different characteristics, including:
The thermal environment (air temperature, radiant temperature, air velocity and humidity).
The visual environment (colour, views, lighting levels, glare, visual information and so on).
The acoustic environment (sound and noise).
Air quality (pollution, smells and so on)
Textures. - Other classifications
Other classifications - Other definitions of the environment include:
Other definitions of the environment include: -
Internal environment. - External environment.
External environment. - Historic environment.
Historic environment. - Ecological environment.
Ecological environment. - Macro environment.
Macro environment. - Business definition
Business definition - The term 'environment' may also be used to describe the conditions within which a business operates. This can include the internal environment within the business itself, and the external environment outside the business that affects its activities. Typically the external environment is broken down into a micro environment and a macro environment.
The term 'environment' may also be used to describe the conditions within which a business operates. This can include the internal environment within the business itself, and the external environment outside the business that affects its activities. Typically the external environment is broken down into a micro environment and a macro environment.
The term 'environment' is also used in relation to computer coding to describe the development environment.
Biodiversity in building design and construction - Victoria Park.jpg
Victoria Park.jpg -
Introduction - Biodiversity is the variety of life in the world or in a particular habitat or ecosystem. It includes:
Biodiversity is the variety of life in the world or in a particular habitat or ecosystem. It includes:
Species diversity. - Ecosystem diversity.
Ecosystem diversity. - Genetic diversity.
Genetic diversity. - Biodiversity sustains all life on Earth.
Biodiversity sustains all life on Earth. -
'Sustaining Life', edited by Chivian and Bernstein details the life available, the impacts on humans and the loss to humans and the environment from extinctions. It is widely thought that the impact of climate change will move the Earth into the sixth great extinction event over the next 50-100 years.
The term 'biodiversity action plan' refers to a nationally used programme that addresses threatened species and habitats and seeks to protect and restore biological systems.
Urban development can have a significant impact on our natural habitats. With habitat modification having been identified as one of the most important drivers of biodiversity loss, the urban environment is becoming an increasingly expanding geographical area that could be used to support wildlife.
From the introduction of green infrastructure, to the engagement and active participation of local communities and city residents, there are numerous ways in which the urban environment can be developed to promote the integration of biodiversity.
For more information see: Biodiversity in the urban environment.
Biodiversity offsetting, is a market tool which enables the off-site creation, restoration or enhancement of habitats as compensation for habitat and species loss resulting from a development.
For more information see: Biodiversity offsetting. -
In December 2018, the UK government began a consultation process which proposed requiring developers to ensure habitats for wildlife are enhanced and left in a measurably better state than they were pre-development.
Lighting control systems - Lighting control systems allow a range of lighting system inputs and outputs to be controlled from a central device. This enables the provision of the optimum level of lighting at the place and time it is needed.
Lighting control systems allow a range of lighting system inputs and outputs to be controlled from a central device. This enables the provision of the optimum level of lighting at the place and time it is needed.
Lighting control systems can be programmed to adjust lighting output based on factors, including:
Time of day. - Activities.
Activities. - Sunrise and sunset.
Sunrise and sunset. - Occupancy levels.
Occupancy levels. - Daylight levels.
Daylight levels. - Combination of factors.
Combination of factors. - The main advantage of installing a lighting control system is that it enables the control of single or multiple lights from a single device, rather than having to be manually or locally controlled. This enables complex pre-sets to be designed depending on the conditions required, and helps to maximise the energy savings that can be made.
The main advantage of installing a lighting control system is that it enables the control of single or multiple lights from a single device, rather than having to be manually or locally controlled. This enables complex pre-sets to be designed depending on the conditions required, and helps to maximise the energy savings that can be made.
Types of lighting include: -
Local manual switching. - Photoelectric control.
Photoelectric control. - Presence detection.
Presence detection. - Absence detection.
Absence detection. -
Natural light - Naturallight.png
Naturallight.png -
In simple terms, natural light is light that is generated naturally, the common source of which is the Sun. This is as opposed to artificial light, which is typically produced by electrical appliances such as lamps.
Natural light is received during daylight hours and coves the visible spectrum with violet at one end and red at the other. Not only is natural light beneficial for health, wellbeing and a good source of Vitamin D, it is required by plants to carry out photosynthesis.
Other sources of natural light include fire and, on clear nights, the moon.
Natural light can play an important role in creating a comfortable environment, helping to regulate the body clock, improve concentration and create a calm, tranquil setting. It can reduce the energy consumption of a building compared to artificial light and can also help prevent mould or mildew from developing in buildings since these spores thrive in darkness.
For more information, see How to maximise natural light.
Typically natural light is transmitted to the interior of a building through glazing such as windows, or through other openings. More complex 'daylight systems' collect natural light and deliver it deep into the heart of buildings. They use collectors in the roof to harvest light, then transport it to diffusers in interior spaces.
Exposure to too much natural light can be a problem for workers on a construction site, particularly during the summer, with the risks of sunburn, heatstroke, and glare obstructing vision.
A right to light is a type of easement referring to the right to receive sufficient light through an opening (such as a window), allowing ordinary comfortable use and enjoyment of a dwelling, or ordinary beneficial use and occupation of other buildings. The levels of acceptable light have not been objectively quantified and are instead assessed on a case-by-case basis by the courts.
Beneficial occupation - Beneficial occupation or beneficial occupancy is a term that can be used to describe a building that is capable of being used for its intended purpose, even though it may have some minor defects.
Beneficial occupation or beneficial occupancy is a term that can be used to describe a building that is capable of being used for its intended purpose, even though it may have some minor defects.
It can be used with reference to the certification of practical completion, which takes place when all the works described in a construction contract have been carried out. This is a very important process as it releases half of the retention (an amount retained from payments due to the contractor to ensure that they complete the works), ends the contractor's liability for liquidated damages and signifies the beginning of the defects liability period.
The defects liability period, which follows certification of practical completion, is not a chance to correct problems apparent at practical completion, it is the period during which the contractor may be recalled to rectify defects which appear. If there are defects apparent before practical completion, then these should be rectified before a certificate of practical completion is issued.
However, practical completion is often certified when there are very minor (de minimis) items 'not affecting beneficial occupancy' that remain incomplete and that can be put right without undue interference or disturbance to occupants, i.e. the client is able to take possession of the works and use them for their intended purpose. The legal basis for this is not clear however. Unless the contract states otherwise, if the works are not complete, the client is not obliged to take possession of them.
See Practical completion for more information. -
Beneficial occupation can also be used in relation to vacant domestic and non-domestic properties In assessing their liability to pay rates. A property that is capable of beneficial occupation (eg a property for which a tenant would pay rent) may be subject to rates. Again, that is not to say that the property is without defects, but that it is capable of beneficial occupation, or with minor alterations would be capable of beneficial occupation.
Moisture content - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Calculating moisture content
2 Calculating moisture content - 3 Reversible and irreversible moisture content
3 Reversible and irreversible moisture content - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - Introduction
Introduction - The term 'moisture content' (or water content) refers to the amount of water that is contained in the pores (voids) of a material. It is usually expressed as the percentage by mass of the water present relative to the materials dry weight. Understanding moisture content can be useful for a number of common materials such as wood, ceramics, soil and so on.
The term 'moisture content' (or water content) refers to the amount of water that is contained in the pores (voids) of a material. It is usually expressed as the percentage by mass of the water present relative to the materials dry weight. Understanding moisture content can be useful for a number of common materials such as wood, ceramics, soil and so on.
Calculating moisture content - To arrive at the moisture content of a material, the following formula can be used:
To arrive at the moisture content of a material, the following formula can be used:
Moisture content (%) = (wet mass dry mass) / dry mass
Moisture content can also be expressed as a ratio that can range from 0 (completely dry) to a materials saturation value. Equilibrium moisture content (EMC) is the point at which a material neither gains nor loses more moisture.
In most substances, the amount of water present will vary due to conditions such as relative humidity and temperature. For example, in most cases, including wood, as the humidity increases, so does the moisture content, while a decrease in humidity leads to a decrease in moisture content.
Acceptable moisture levels in wood are typically: -
Wood flooring 6-8% - Furniture 6-9%
Furniture 6-9% - Construction 9-14%
Construction 9-14% - Materials such as glass, most plastics and steel have no pores and so have almost zero porosity. This means they are literally devoid of having an internal surface area into which moisture can penetrate, be absorbed or be transmitted through.
Materials such as glass, most plastics and steel have no pores and so have almost zero porosity. This means they are literally devoid of having an internal surface area into which moisture can penetrate, be absorbed or be transmitted through.
Reversible and irreversible moisture content - Variations in the moisture content of materials can cause movement in buildings. In porous building materials, moisture content changes can cause reversible or irreversible movement.
Variations in the moisture content of materials can cause movement in buildings. In porous building materials, moisture content changes can cause reversible or irreversible movement.
Irreversible moisture movement is seen, for example, in bricks that have just been manufactured: just out of the kiln, clay bricks will be very dry and will start to absorb moisture immediately causing irreversible expansion. In contrast, calcium silicate bricks are cured by an autoclave process using heat and steam; they will be more saturated than normal bricks and, as their moisture content drops to achieve an equilibrium with that of the atmosphere, they will shrink. Both these examples illustrate why some building materials should not be used immediately for building.
Reversible moisture expansion is seen in some materials that are part of a building structure. They generally expand when wet and shrink when dry. In doing so, they can have dramatic and unfortunate consequences on a building if their behaviours are not understood and accounted for. They therefore require thoughtful and intelligent detailing e.g movement joints, to maximise the life and aesthetics of the construction.
High moisture content can cause problems, especially when allied with changes in temperature. Saturated brickwork under freezing conditions causes a phenomenon called spalling where the face of the brickwork is badly damaged, usually requiring rebuilding or refacing. The mechanism responsible is freezing which causes expansion of the water present in the pores of the material, thereby exerting pressure on the front surface of the brick.
Wet rot is a generic name given to a range of conditions that can affect timber where there is the continual presence of moisture, perhaps caused by leaking pipework, poor ventilation (resulting in condensation), rising or penetrating damp and so on. For more information see: Wet rot.
Most moulds require relatively high levels of moisture in order to grow. The majority require an equivalent of at least 70% relative humidity to thrive and most large mould outbreaks in buildings, occur where porous, cellulose-type materials contain persistent liquid water or condensation. For more information see: Mould growth in buildings.
Soils can also change with moisture content. For example, ground heave is the upward movement of the ground usually associated with the expansion of clay soils which swell when wet. As the soil generally cannot expand downwards or sideways, the result is that the exposed upper surface of the soil rises up. For more information see: Ground heave.
With soils, moisture content can be estimated by satellites using microwave remote sensing. This is achieved by contrasting the difference between the dielectric properties of wet and dry soil. Microwave radiation is largely unaffected by the atmosphere and so can penetrate cloud cover. It can also penetrate vegetation through to the ground surface.
Absorption - Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014 defines absorption as: A process in which one substance, usually a liquid or gas, permeates into, or is dissolved by, a liquid or solid.
Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014 defines absorption as: A process in which one substance, usually a liquid or gas, permeates into, or is dissolved by, a liquid or solid.
Absorption may also refer to things that are not substances, such as sound, light, impact and so on.
Articles about absorption on Designing Buildings Wiki include:
Absorption heat pump. - Absorption refrigeration.
Absorption refrigeration. - Acoustic absorption.
Acoustic absorption. - Thermal optical properties.
NB Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines absorption as: A process in which a solid holds a gas or liquid within its open volume.
Sound absorption - Sound absorption is the loss of sound energy when sound waves comes into contact with an absorbent material such as ceilings, walls, floors and other objects, as a result of which, the sound is not reflected back into the space.
Sound absorption is the loss of sound energy when sound waves comes into contact with an absorbent material such as ceilings, walls, floors and other objects, as a result of which, the sound is not reflected back into the space.
Sound absorbent materials can be used to create a suitable acoustic environment within a space by reducing the reverberation time. Reverberation affects the way a space 'sounds'. A long reverberation time can make a room sound loud and noisy and causes speech to sound muffled and muddy. Rooms designed for speech therefore typically have a short reverberation time of less than 1 second. Conversely, a longer reverberation time can enhance a music hall by adding richness, depth and warmth to music.
Sound absorption can be a particularly important factor for spaces such as:
Sports halls. - Schools.
Schools. - Recording studios.
Recording studios. - Lecture theatres.
Lecture theatres. - Concert venues, cinemas and theatres.
Concert venues, cinemas and theatres. - Generally, sound absorption is applied in the form of treatment to floors, walls, ceilings, partition surfaces and objects such as chairs or bookshelves. The use of sound absorbing screens is also becoming more common.
Generally, sound absorption is applied in the form of treatment to floors, walls, ceilings, partition surfaces and objects such as chairs or bookshelves. The use of sound absorbing screens is also becoming more common.
Sound absorbers can be divided into three main categories:
Porous absorbents. - Resonance absorbents.
Resonance absorbents. - Single absorbents.
Single absorbents. - Porous absorbents conventionally take two forms; fibrous materials or open-celled foam. Fibrous materials absorb sound as sound waves force the fibres to bend and this bending of the fibres generates heat. The conversion of acoustic energy into heat energy results in the sound effectively being absorbed. In the case of open-celled foam, the air movement resulting from sound waves pushes air particles through the narrow passages which in turn generate a viscous loss along with heat.
Porous absorbents conventionally take two forms; fibrous materials or open-celled foam. Fibrous materials absorb sound as sound waves force the fibres to bend and this bending of the fibres generates heat. The conversion of acoustic energy into heat energy results in the sound effectively being absorbed. In the case of open-celled foam, the air movement resulting from sound waves pushes air particles through the narrow passages which in turn generate a viscous loss along with heat.
Usually a materials thickness has the greatest impact on its sound absorbing qualities. The thickness of materials can be compensated for with air space behind a wall panel or acoustic ceiling to improve performance at lower frequencies.
It is generally better to not include an airtight layer on the surface, such as a vapour barrier or paint layer, as this may reduce the sound absorbing qualities. However, architecturally, fibrous materials and open celled foams are not always considered attractive or robust. It is common therefore to cover these materials with an acoustically transparent finish such as a tissue, cloth or slatted wood, or with perforated materials such as wood, metal, plasterboard and so on.
Resonance absorbents consist of a mechanical or acoustic oscillation system, such as membrane absorbers, where there is a solid plate with a tight air space behind. Absorption reaches its maximum at the resonance frequency. The cavity can be filled with a porous material, to broaden the absorption over the range of frequency.
Single absorbers can be tables, chairs or other objects.
The sound absorbing characteristics of acoustical materials varies significantly with frequency. Low frequency sounds, below 500 Hz, tend to be more difficult to absorb whereas high frequencies sounds, above 500 Hz, are easier to absorb.
A material's sound absorbing properties can be expressed by the sound absorption coefficient, alpha, as a function of frequency. Alpha ranges from 0 (total reflection) to 1.00 (total absorption).
NB: Sound absorption is not the same as sound insulation which is used to prevent sound travelling between separate spaces across a partition such as a wall, ceiling or floor. Sound absorbing materials can convert some of the absorbed sound energy into heat, rather than transmitting it, which improve sound insulation, but it should not be seen as a substitute for adequate sound insulation.
Furniture - Interiordesign2000s.png
Interiordesign2000s.png -
The term furniture refers to moveable objects that are used to support human activities in the built environment. However, it can also be used more widely to refer to fitted objects and equipment.
Furniture tends to be of a craft-based design type that can be functional, decorative, symbolic, ceremonial, and so on. Many different materials are used in the manufacture of furniture, most commonly; timber, metal, plastic, fabrics, leather, and so on.
Furniture is subject to frequent changes in fashion, and tastes for furniture can vary widely from person to person.
Some of the main types of furniture include:
Furniture for sitting: Chairs, stools, sofas, futons, etc.
Furniture for eating or working: Tables, desks, etc.
Furniture for sleeping: Beds, cots, bunks, etc.
Furniture for storage: chests, wardrobes, etc.
Garden furniture: Chairs, tables, etc.
Street furniture: Benches, barriers, street lamps, traffic lights, bollards, etc.
Furniture can be grouped together with other components as 'FF&E' (furniture, fixture and equipment). FF&E might be procured separately to the main construction contract (or elements of them), particularly by clients that already have systems in place for procuring fixed and loose furniture, fittings and equipment; for example, schools, universities, or hospitals. For more information, see Furniture fixtures and equipment FF&E.
Interior designers are often associated with specifying furniture, analysing how a space is to be used and how best it can be planned with the most appropriate objects, considering functionality, aesthetic, space efficiency, circulation requirements, and so on. For more information, see Interior design
The Furniture and Furnishings (Fire Safety) Regulations define requirements for the fire resistance for domestic upholstered furniture, furnishings and other products containing upholstery. These Regulations are enforced by Trading Standards.
Introduction - Biomass (or bio-feedstock) is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. Whilst both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered 'carbon neutral'.
Biomass (or bio-feedstock) is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. Whilst both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered 'carbon neutral'.
Solid bioenergy options include woodchips and pellets. Using these types of biomass fuel as a heating source is well established across Europe and the UK. The use of biomass as an energy source is traditionally through combustion within a biomass boiler, providing hot water. This technology can be a central boiler supplying heat via district heating or individual biomass stoves or boilers in each property.
Biomass fuel can also be used to generate power through Combined Heat and Power (CHP) technology. Small scale biomass CHP systems are in development, but they are still considered to be an emerging technology. The specific requirements of a biomass CHP system are similar to a biomass boiler, with the notable difference being additional space requirements, particularly height.
Technical Information - The following figures can be used to determine the approximate storage area required (the actual volume will depend on the moisture content of the fuel):
The following figures can be used to determine the approximate storage area required (the actual volume will depend on the moisture content of the fuel):
Pellets: 3,000 kWh/m fuel - Chips: 800 kWh/m fuel
Chips: 800 kWh/m fuel - Storing more than two months supply is not recommended because of potential problems with decay and fungal growth.
Storing more than two months supply is not recommended because of potential problems with decay and fungal growth.
Five litres of combustion ash is produced by each of the following:
1,000 litres of wood pellets - 15 litres of wood chips
15 litres of wood chips - Attention must be paid to chimney heights. Biomass boilers have to be certified as 'clean' for smoke controlled zones.
Attention must be paid to chimney heights. Biomass boilers have to be certified as 'clean' for smoke controlled zones.
Exhaust gases are cleaner than those from oil-fired boilers.
Feeding systems for boilers greater than 2MW becomes more complicated and requires moving floors etc.
Loading - Generally biomass systems should be sized lower than peak loads as these occur infrequently. The Carbon Trust has developed a sophisticated tool for sizing boilers and storage requirements.
Generally biomass systems should be sized lower than peak loads as these occur infrequently. The Carbon Trust has developed a sophisticated tool for sizing boilers and storage requirements.
Biomass boilers turndown (the amount by which heat output can be reduced from the maximum without switching off) is usually 20-30% on dry fuel and 40% on wet fuel. This dictates sizing unless a buffer tank is used.
Commonly a gas/oil back up boiler (or burner) will be specified to provide fuel resilience in case of supply chain problems, this boiler can also be used to 'top-up' to a peak load capacity. An exception to this might be small domestic applications where fitting two boilers may be uneconomic. Typically a biomass boiler sized at around 30-40% peak load will supply 60-70% of heating consumption over a year..
Wood Resources - In 2007, The Woodfuel Strategy for England estimated that there was a resource of 3.5 million tonnes of green wood per annum, with a potential for 5.5 million tonnes by 2020.
In 2007, The Woodfuel Strategy for England estimated that there was a resource of 3.5 million tonnes of green wood per annum, with a potential for 5.5 million tonnes by 2020.
However, some members of the AECB (The Association for Environment Conscious Building) are against biomass (see AECB discussion paper on biomass) on the basis that wood used in boilers could otherwise be used in other wood products that don't release CO2 into the atmosphere. This caused a lot of heated debate and many members felt that the AECB had taken a position on the issue without consulting its members.
In July 2013, the UK government appeared to turn away from biomass when it capped subsidies for bespoke biomass burning plants and announced that it would end subsidies for biomass burning in existing stations by 2027. This followed a report from the BBC revealing that millions of tonnes of wood were being shipped from the USA to help meet Britain's renewables targets.
Air Quality Management - In general, cities must monitor their air quality, and if certain emission are above advisory thresholds they must implement an Air Quality Management Plan (AQMP). It is possible that where there is an AQMP, part of this plan might be to limit biomass installations. However, air quality is predominately a function of diesel powered transport and so it could be argued that restricting biomass boilers is not tackling the root of the problem.
In general, cities must monitor their air quality, and if certain emission are above advisory thresholds they must implement an Air Quality Management Plan (AQMP). It is possible that where there is an AQMP, part of this plan might be to limit biomass installations. However, air quality is predominately a function of diesel powered transport and so it could be argued that restricting biomass boilers is not tackling the root of the problem.
Notes and other definitions - NB: Waste wood and other wastes in the UK fall under the Waste Incineration Directive (WID) and require expensive treatment to reduce harmful emissions.
NB: Waste wood and other wastes in the UK fall under the Waste Incineration Directive (WID) and require expensive treatment to reduce harmful emissions.
NB Climate Emergency Design Guide: How new buildings can meet UK climate change, published by The London Energy Transformation Initiative (LETI) in January 2020 defines a biomass boiler as: A form of direct combustion, heating and/or electricity derived from biomass (agricultural, forest, urban or industrial residues as opposed to fossil fuel).
Making Mission Possible - Delivering A Net-Zero Economy, published by the Energy Transitions Commission (ETC) in September 2020, defines sustainable biomass / bio-feedstock / bioenergy as: '...biomass that is produced without triggering any destructive land use change (in particular deforestation), is grown and harvested in a way that is mindful of ecological considerations (such as biodiversity and soil health), and has a lifecycle carbon footprint at least 50% lower than the fossil fuels alternative (considering the opportunity cost of the land, as well as the timing of carbon sequestration and carbon release specific to each form of bio-feedstock and use).
NB The Energy White Paper, Powering our Net Zero Future (CP 337), published in December 2020 by HM Government, suggests that bioenergy: 'Refers to heat or electricity produced using biomass or gaseous and liquid fuels with a biological origin such as biomethane produced from biomass.' Where biomass: 'Refers to any material of biological origin used as a feedstock for products (e.g. wood in construction to make chemicals and materials, like bio-based plastics), or as a fuel for bioenergy (heat, electricity and gaseous fuels such as biomethane and hydrogen) or biofuels (transport fuels).'
Emissions Gap Report 2019 published by the UN Environment Programme defines bioenergy as: Energy derived from any form of biomass such as recently living organisms or their metabolic by-products.
Combined heat and power CHP - Combined heat and power (CHP), sometimes referred to as cogeneration, is a process in which the heat that is created as a by-product of power generation is captured and used rather than simply being wasted.
Combined heat and power (CHP), sometimes referred to as cogeneration, is a process in which the heat that is created as a by-product of power generation is captured and used rather than simply being wasted.
According to the Combined Heat and Power Association, In todays coal and gas fired power stations, up to two thirds of the overall energy consumed is lost in this way, often seen as a cloud of steam rising from cooling towers.
Whilst there are a range of different forms of CHP, typically, a gas-powered turbine or reciprocating engine is used to produce electricity, and the heat recovered is used for local water or space heating, or to support an industrial process. Increasingly absorption cooling can use the heat recovered to produce cooling. Sometimes this process is referred to as trigeneration or combined cooling, heat and power (CCHP).
Alternative systems have heat generation as their primary function, and then use a steam turbine to generate electricity.
CHP as a process is not dependent on a specific fuel and so renewable fuels such as biomass feedstocks can be used.
Very broadly, CHP is appropriate in circumstances where there is a continuous local demand for heat and power, such as district heating schemes, hotels and leisure centres, industrial applications that require heat for manufacturing processes and so on. If excess electricity is generated, this can be exported back to the national grid.
The Department of Energy and Climate Change (DECC) lists the advantages of CHP as:
An efficiency of over 80%, compared to 38% for a coal-fired power station.
Up to 30% savings on energy bills.
Up to 30% reduction in carbon emissions.
Reduced transmission and distribution losses. - Increased fuel supply security.
Increased fuel supply security. - CHP can be a very significant investment and requires careful consideration. However, where they are certified as Good Quality (GQ)CHP, they are exempt from the Climate Change Levy for fuel inputs and electricity outputs. They may also qualify as Enhanced Capital Allowances (ECA) and be eligible for business rates exemption.
CHP can be a very significant investment and requires careful consideration. However, where they are certified as Good Quality (GQ)CHP, they are exempt from the Climate Change Levy for fuel inputs and electricity outputs. They may also qualify as Enhanced Capital Allowances (ECA) and be eligible for business rates exemption.
CHP plant can be manufactured as packaged units or can be custom designed and built. Increasingly, micro CHP units can be used to supply small-scale and domestic needs. In effect, these replace conventional boilers. Heat is the primary output of micro CHP, with the ratio of heat to electricity for domestic appliances typically around 6:1, generating up to 1kW of electricity. As with larger CHP plant, if excess electricity is generated, this can be exported back to the national grid. This may be eligible for Feed-in Tariffs in England and Wales and is considered an eligible measure suitable for funding under the Green Deal.
Design Framework for Building Services 5th Edition (BG 6/2018), written by David Churcher, John Sands & Martin Ronceray, and published by BSRIA in June 2018 defines a clash as: Two distinct elements occupying the same space. Space for access, installation and maintenance must be allowed for.
It identifies three types of acceptable clash: -
Critical: Major clash - must be resolved at this stage.
Moderate: Easily resolvable does not have a major impact on ongoing design. Can be resolved at a future stage.
Allowable: Acceptable clash resolution not required in the design model.
--BSRIA -
See also: Clash avoidance. -
Natural ventilation of buildings - Open window.jpg
Open window.jpg -
Ventilation is necessary in buildings to remove stale air and replace it with fresh air:
Helping to moderate internal temperatures. - Helping to moderate internal humidity.
Helping to moderate internal humidity. - Replenishing oxygen.
Replenishing oxygen. - Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
Creating air movement which improves the comfort of occupants.
Very broadly, ventilation in buildings can be classified as natural or mechanical.
Mechanical (or forced) ventilation is driven by fans or other mechanical plant.
Natural ventilation is driven by pressure differences between one part of a building and another, or pressure differences between the inside and outside. For more information see Natural ventilation.
Mixed mode, hybrid or assisted ventilation systems involve natural ventilation supplemented by mechanical systems.
Natural ventilation tends to cost less to build, operate and maintain than mechanical ventilation, and so this is generally the first option investigated during the design process. However, there may be circumstances where natural ventilation is not possible and so mechanical ventilation is necessary:
The building is too deep to ventilate from the perimeter.
Local air quality is poor, for example if a building is next to a busy road.
Local noise levels mean that windows cannot be opened.
The local urban structure is very dense and shelters the building from the wind.
Air cooling or air conditioning systems mean that windows cannot be opened.
Privacy or security requirements prevent windows being opened.
Internal partitions block air paths. - The creation of draughts adjacent to openings.
The creation of draughts adjacent to openings. - Some of these issues can be avoided or mitigated by careful location, orientation, siting, zoning and design of the building.
Some of these issues can be avoided or mitigated by careful location, orientation, siting, zoning and design of the building.
Natural ventilation is generally categorised as: -
Wind-driven (or wind-induced) cross ventilation, where pressure differences between one side of the building and the other draw air in on the high pressure side and draw it out on the low pressure side.
Buoyancy-driven stack ventilation (the stack effect), where cooler air enters the building at low level, is heated by occupants, equipment, heating systems and so on, becomes less dense and so more buoyant and rises through the building to be ventilated to the outside at the top.
The effectiveness of these mechanisms is dependent on a wide number of variables, but very broadly:
Cross ventilation is suitable for buildings up to approximately 12 to 15m in depth (five times the floor to ceiling height, or 2.5 times the floor to ceiling height if openings can only be provided on one side). Beyond this, providing sufficient fresh air creates draughts close to openings, and additional design elements such as internal courtyards are necessary, or the inclusion of elements such as atrium that combine cross ventilation and stack effects. A disadvantage of cross ventilation is that it tends to be least effective on hot still days, when it is needed most.
The effectiveness of stack ventilation is influenced by; the effective area of openings, the height of the stack, the temperature difference between the bottom and the top of the stack and pressure differences outside the building. Where ventilation is needed high up in the building, this can require the addition of ventilation stacks that achieve the height necessary to create a pressure difference between the inlets and outlets. See Stack effect for more information.
Combinations of these ventilation strategies, with the additional exploitation of thermal mass can produce a wide range of natural ventilation solutions, such as trombe walls, solar chimneys and so on.
Passive design.jpg -
Designing natural ventilation can become extremely complex because of the interaction between cross ventilation and the stack effect as well as complex building geometries and the distribution of openings. This can require analysis using specialist software analysis systems such as computational fluid dynamics.
Natural ventilation can also be influenced by occupant behaviour, for example, a person near to a window choosing to close it. For this reason it can be beneficial to automate natural ventilation systems, or to provide training for occupants. It is important then to monitor behaviour to ensure systems continue to be operated as intended.
Automation of ventilation systems can leave occupants feeling disempowered, unable to locally influence the conditions around them (for example by opening or closing a window) and consequently more likely to be dissatisfied with those conditions.
In modern buildings, which tend to be designed to be completely sealed from the outside unless windows or other ventilators are open, problems, such as condensation, can occur during the winter when openings are closed. As a result, trickle ventilation, or 'background' ventilation tends to be provided to ensure there is always an adequate level of ventilation. Trickle ventilators can be self-balancing, with the size of the open area depending on the air pressure difference across it.
It is possible, although relatively complicated to include heat recovery in natural ventilation systems so that during cooler conditions, heat recovered from extract air is used to pre-heat fresh air entering the building.
In addition, thermal mass can be used to pre-heat supply air. For example, see Thermal Labyrinth and Ground preconditioning of supply air.
Schematic section.jpg -
Ventilation in buildings is regulated by Part F of the building regulations. Approved document F includes standards for ventilation and air quality for all buildings and requirements for the prevention of condensation. The types of ventilation covered include; mechanical, passive stack, background and purge (rapid).
Mechanical ventilation of buildings - Mechanical ventilation.jpg
Mechanical ventilation.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of mechanical ventilation
2 Types of mechanical ventilation - 3 Typical mechanical ventilation systems for commercial buildings
3 Typical mechanical ventilation systems for commercial buildings - 4 Building management systems
4 Building management systems - 5 Building regulations requirements
5 Building regulations requirements - 6 Related articles on Designing Buildings Wiki
6 Related articles on Designing Buildings Wiki - Introduction
Introduction - Ventilation is necessary in buildings to remove stale air and replace it with fresh air:
Ventilation is necessary in buildings to remove stale air and replace it with fresh air:
Helping to moderate internal temperatures. - Helping to moderate internal humidity.
Helping to moderate internal humidity. - Replenishing oxygen.
Replenishing oxygen. - Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
Creating air movement which improves the comfort of occupants.
Very broadly, ventilation in buildings can be classified as natural or mechanical.
Mechanical (or forced) ventilation is driven by fans or other mechanical plant.
Natural ventilation is driven by pressure differences between one part of a building and another, or pressure differences between the inside and outside. For more information see Natural ventilation.
Natural ventilation is generally preferable to mechanical ventilation as it will typically have lower capital, operational and maintenance costs. However, there are a range of circumstances in which natural ventilation may not be possible:
The building is too deep to ventilate from the perimeter.
Local air quality is poor, for example if a building is next to a busy road.
Local noise levels mean that windows cannot be opened.
The local urban structure is very dense and shelters the building from the wind.
Privacy or security requirements prevent windows from being opened.
Internal partitions block air paths. - The density of occupation, equipment, lighting and so on creates very high heat loads or high levels of contaminants.
The density of occupation, equipment, lighting and so on creates very high heat loads or high levels of contaminants.
Some of these issues can be avoided or mitigated by careful design, and mixed mode or assisted ventilation might be possible, where natural ventilation is supplemented by mechanical systems.
Types of mechanical ventilation - Where mechanical ventilation is necessary it can be:
Where mechanical ventilation is necessary it can be:
A circulation system such as a ceiling fan, which creates internal air movement, but does not introduce fresh air.
A pressure system, in which fresh outside air is blown into the building by inlet fans, creating a higher internal pressure than the outside air.
A vacuum system, in which stale internal air is extracted from the building by an exhaust fan, creating lower pressure inside the building than the outside air.
A balanced system that uses both inlet and extract fans, maintaining the internal air pressure at a similar level to the outside air and so reducing air infiltration and draughts.
A local exhaust system that extracts local sources of heat or contaminants at their source, such as cooker hoods, fume cupboards and so on.
Ceiling-fan-1016677 640.jpg Extract fan.jpg Air-conditioning-233953 640.jpg
Typical mechanical ventilation systems for commercial buildings - In commercial developments, mechanical ventilation is typically driven by air handling units (AHU) connected to ductwork within the building that supplies air to and extracts air from interior spaces. Typically AHU comprise an insulated box that forms the housing for; filter racks or chambers, a fan (or blower), and sometimes heating elements, cooling elements, sound attenuators and dampers. In some situations, such as in swimming pools, air handling units might include dehumidification. See Air handling units for more information.
In commercial developments, mechanical ventilation is typically driven by air handling units (AHU) connected to ductwork within the building that supplies air to and extracts air from interior spaces. Typically AHU comprise an insulated box that forms the housing for; filter racks or chambers, a fan (or blower), and sometimes heating elements, cooling elements, sound attenuators and dampers. In some situations, such as in swimming pools, air handling units might include dehumidification. See Air handling units for more information.
Where mechanical ventilation includes heating, cooling and humidity control, this can be referred to as Heating Ventilation and Air Conditioning (HVAC). See Heating Ventilation and Air Conditioning for more information.
Extracting internal air and replacing it with outside air can increase the need for heating and cooling. This can be reduced by re-circulating a proportion of internal air with the fresh outside air, or by heat recovery ventilation (HRV) that recovers heat from extract air to pre-heat incoming fresh air using counter-flow heat exchangers. See Heat recovery ventilation for more information.
The design of mechanical ventilation systems is generally a specialist task, undertaken by a building services engineer. Whilst there are standards and rules of thumb that can be used to determine air flow rates for straight-forward situations, when mechanical ventilation is combined with heating, cooling, humidity control and the interaction with natural ventilation, thermal mass and solar gain, the situation can quickly become very complicated.
This, along with additional considerations, such as the noise generated by fans, and the impact of ductwork on acoustic separation means it is vital building services are considered at the outset of the building design process, and not seen as an add-on.
See Building services engineer for more information. -
Building management systems - Mechanical ventilation may be controlled by a building management system (BMS) to maximise occupant comfort and minimise energy consumption. Regular inspection and maintenance is necessary to ensure that systems are operating optimally and that occupants understand how systems are operated.
Mechanical ventilation may be controlled by a building management system (BMS) to maximise occupant comfort and minimise energy consumption. Regular inspection and maintenance is necessary to ensure that systems are operating optimally and that occupants understand how systems are operated.
See Building management system for more information. -
Building regulations requirements - Ventilation in buildings is regulated by Part F of the building regulations. Approved document F includes standards for ventilation and air quality for all buildings and requirements for the prevention of condensation. The types of ventilation covered include; mechanical, passive stack, background and purge (rapid).
Ventilation in buildings is regulated by Part F of the building regulations. Approved document F includes standards for ventilation and air quality for all buildings and requirements for the prevention of condensation. The types of ventilation covered include; mechanical, passive stack, background and purge (rapid).
It is supported by the Domestic Ventilation Compliance Guide, which provides detailed guidance about the installation, inspection, testing, commissioning and provision of information when installing fixed ventilation systems in new and existing dwellings.
See Approved document F for more information. -
Cross ventilation - Crossventilation.jpg
Crossventilation.jpg -
Ventilation is necessary in buildings to remove stale air and replace it with fresh air:
Helping to moderate internal temperatures. - Reducing the accumulation of moisture, odours and other gases that can build up during occupied periods.
Reducing the accumulation of moisture, odours and other gases that can build up during occupied periods.
Creating air movement which improves the comfort of occupants.
Very broadly, ventilation in buildings can be classified as natural or mechanical.
Mechanical (or forced) ventilation tends to be driven by fans.
Natural ventilation is driven by natural pressure differences from one part of the building to another.
Natural ventilation can be wind-driven (or wind-induced), or it can be buoyancy-driven stack ventilation. For more information about buoyancy-driven stack ventilation, see Stack effect.
Cross ventilation occurs where there are pressure differences between one side of a building and the other. Typically, this is a wind-driven effect in which air is drawn into the building on the high pressure windward side and is drawn out of the building on the low pressure leeward side. Wind can also drive single-sided ventilation and vertical ventilation.
Whereas cross ventilation is generally more straight-forward to provide than stack ventilation, it has the disadvantage that it tends to be least effective on hot, still days, when it is needed most. In addition, it is generally only suitable for narrow buildings.
If there are windows on both sides, then cross ventilation might be suitable for buildings where the width is up to five times the floor-to-ceiling height. Where there are only openings on one side, wind-driven ventilation might be suitable for buildings where the width is up to 2.5 times the floor to ceiling height.
Beyond this, providing sufficient fresh air creates draughts close to openings, and additional design elements such as internal courtyards are necessary, or the inclusion of elements such as atrium that combine cross ventilation and stack effects, or mechanically assisted ventilation.
Cross ventilation is most suited for buildings that are:
Narrow. - On exposed sites.
On exposed sites. - Perpendicular to the prevailing wind.
Perpendicular to the prevailing wind. - Free from internal barriers to air flow.
Free from internal barriers to air flow. - Provided with a regular distribution of openings.
Provided with a regular distribution of openings. - It is less suitable where:
It is less suitable where: -
The building is too deep to ventilate from the perimeter.
Local air quality is poor; for example, if a building is next to a busy road.
Local noise levels mean that windows cannot be opened.
The local urban structure is very dense and shelters the building from the wind.
Privacy or security requirements prevent windows being opened.
Internal partitions block air paths. - Some of these issues can be avoided or mitigated by careful siting and design of buildings. For example, louvres can be used where ventilation is required, but a window is not, and ducts or openings can be provided in internal partitions, although these will only be effective if there is sufficient open area, and there may be problems with acoustic separation.
Some of these issues can be avoided or mitigated by careful siting and design of buildings. For example, louvres can be used where ventilation is required, but a window is not, and ducts or openings can be provided in internal partitions, although these will only be effective if there is sufficient open area, and there may be problems with acoustic separation.
Cross ventilation can be problematic during the winter when windows may be closed, particularly in modern buildings which tend to be highly sealed. Trickle ventilation, or crack settings on windows can be provided to ensure there is adequate background ventilation. Trickle ventilators can be self-balancing, with the size of the open area depending on the air pressure difference across it.
In straight-forward buildings, cross ventilation can often be designed by following rules of thumb for the openable area required for a given floor area, depending on the nature of the space and occupancy. The situation becomes more complicated when cross ventilation is combined with the stack effect or mechanical systems, and thermal mass and solar gain are taken into consideration. Modelling this behaviour can become extremely complicated, sometimes requiring the use of local weather data, software such as computational fluid dynamics (CFD) programs and even wind tunnel testing.
Renewable energy - Contents
Contents - [hide]
[hide] - 1 Background
1 Background - 2 Renewable energy
2 Renewable energy - 2.1 Solar
2.1 Solar - 2.1.1 Solar photovoltaics
2.1.1 Solar photovoltaics - 2.1.2 Solar thermal energy
2.1.2 Solar thermal energy - 2.2 Geothermal energy
2.2 Geothermal energy - 2.3 Heat pumps
2.3 Heat pumps - 2.3.1 Ground source heat pumps.
2.3.1 Ground source heat pumps. - 2.3.2 Air-source heat pumps
2.3.2 Air-source heat pumps - 2.3.3 Water source heat pumps
2.3.3 Water source heat pumps - 2.4 Tidal power
2.4 Tidal power - 2.4.1 Tidal range
2.4.1 Tidal range - 2.4.2 Tidal stream
2.4.2 Tidal stream - 2.5 Wave power
2.5 Wave power - 2.6 Hydro electric
2.6 Hydro electric - 2.7 Wind
2.7 Wind - 2.8 Biomass
2.8 Biomass - 2.9 Waste
2.9 Waste - 2.9.1 Combustion/incineration
2.9.1 Combustion/incineration - 2.9.2 Gasification and pyrolysis
2.9.2 Gasification and pyrolysis - 2.9.3 Anaerobic digestion/biogas
2.9.3 Anaerobic digestion/biogas - 3 Limitations of renewable energy
3 Limitations of renewable energy - 4 Nuclear energy
4 Nuclear energy - 5 Incentives
5 Incentives - 5.1 Feed in tariff
5.1 Feed in tariff - 5.2 Renewable heat incentive
5.2 Renewable heat incentive - 5.3 Green deal
5.3 Green deal - 5.4 Climate change levy
5.4 Climate change levy - 6 Related articles on Designing Buildings Wiki
6 Related articles on Designing Buildings Wiki - 7 External references
7 External references - Background
Background - Our society on earth is heavily dependent on fossil fuels such as oil, gas and coal, and is likely to remain dependent on them for much of this century (Odell, 2009).
Our society on earth is heavily dependent on fossil fuels such as oil, gas and coal, and is likely to remain dependent on them for much of this century (Odell, 2009).
Every year we emit more than 20 billion tonnes of carbon into the atmosphere by burning fossil fuels, half of which is absorbed in the seas and by vegetation, and half of which remains in the atmosphere (Comby, 2008). The impact on human and natural systems is potentially irreparable (Schellnhuber et al, 2006). In addition, as fuels deplete and demand increases, so supplies become more vulnerable to disruption.
According to the International Energy Agency (IEA, 1999), 'the world is in the early stages of an inevitable transition to a sustainable energy system that will be largely dependent on renewable resources'. In 2009, US President Barack Obama said, to truly transform our economy, protect our security, and save our planet from the ravages of climate change, we need to ultimately make clean, renewable energy the profitable kind of energy.
In 2007, European Union (EU) countries committed to set a binding target that 20% of the EU's total energy supply should come from renewables by 2020 (European Union Committee, 2008). For the UK, the target is 15%, almost a seven-fold increase in the share of renewables in scarcely more than a decade (HM Government, 2009).
Renewable energy - Renewable energy is derived from sources which are naturally replenished or are practically inexhaustible. They are often described as 'clean', 'green' or 'sustainable' forms of energy because of their minimal environmental impact compared to fossil fuels.
Renewable energy is derived from sources which are naturally replenished or are practically inexhaustible. They are often described as 'clean', 'green' or 'sustainable' forms of energy because of their minimal environmental impact compared to fossil fuels.
However, there is some controversy about which forms of energy are genuinely renewable, as there are inevitable environmental consequences from any form of energy production and consumption:
Manufacture, transportation and installation of equipment. - Maintenance of equipment.
Maintenance of equipment. - Decommissioning.
Decommissioning. - Distribution of energy.
Distribution of energy. - Habitat destruction (such as soil erosion or deforestation).
Habitat destruction (such as soil erosion or deforestation).
Displacement of other activities (such as food production).
Waste products. - The National Planning Policy Framework (NPPF) suggests that renewable and low-carbon energy: 'Includes energy for heating and cooling as well as generating electricity. Renewable energy covers those energy flows that occur naturally and repeatedly in the environment from the wind, the fall of water, the movement of the oceans, from the sun and also from biomass and deep geothermal heat. Low carbon technologies are those that can help reduce emissions (compared to conventional use of fossil fuels).'
The National Planning Policy Framework (NPPF) suggests that renewable and low-carbon energy: 'Includes energy for heating and cooling as well as generating electricity. Renewable energy covers those energy flows that occur naturally and repeatedly in the environment from the wind, the fall of water, the movement of the oceans, from the sun and also from biomass and deep geothermal heat. Low carbon technologies are those that can help reduce emissions (compared to conventional use of fossil fuels).'
Very broadly the range of energy production techniques that have been described as 'renewable' includes:
Solar - Solar photovoltaics
Solar photovoltaics - Solar cells, or photovoltaic (PV) cells, convert sunlight directly into electricity. Photovoltaics gets its name from the process of converting light (photons) to electricity (voltage). See Solar photovoltaics for more information.
Solar cells, or photovoltaic (PV) cells, convert sunlight directly into electricity. Photovoltaics gets its name from the process of converting light (photons) to electricity (voltage). See Solar photovoltaics for more information.
Solar thermal energy - The term 'solar thermal' is used to describe a system where the energy from the sun is harvested to be used for its heat. Small scale solar thermal collectors can be used for heating swimming pools or supplying building heating systems. Large scale solar thermal collectors use mirrors or lenses to focus solar radiation; allowing much higher temperatures to be generated.
The term 'solar thermal' is used to describe a system where the energy from the sun is harvested to be used for its heat. Small scale solar thermal collectors can be used for heating swimming pools or supplying building heating systems. Large scale solar thermal collectors use mirrors or lenses to focus solar radiation; allowing much higher temperatures to be generated.
See Solar thermal systems and Large scale solar thermal energy for more information.
NB: The use of the term 'solar thermal' is also associated with the integration of 'passive' heating and cooling technologies in buildings.
Geothermal energy - Geothermal energy is the second most abundant source of heat on earth after solar energy. It is the natural heat energy stored in the earth itself. Geothermal temperature increases with depth in the earth's crust. Using the technology available at present, it has been found that the average geothermal gradient is about 3C per 100 m (Dincer et al., 2007).
Geothermal energy is the second most abundant source of heat on earth after solar energy. It is the natural heat energy stored in the earth itself. Geothermal temperature increases with depth in the earth's crust. Using the technology available at present, it has been found that the average geothermal gradient is about 3C per 100 m (Dincer et al., 2007).
Geothermal energy has been used on a commercial scale for over 100 years and more than 70 countries now exploit geothermal resources for electricity generation, space heating, hot water supply, cooling, industrial and agricultural uses. See Geothermal energy for more information.
Heat pumps - Ground source heat pumps.
Ground source heat pumps. - The temperature of the surface layers of the ground remains fairly constant below a depth of approximately 7-10 m, at the mean ambient air temperature regardless of the time of year. Depending on the location and depth, this temperature is typically between 7C and 13C in the UK. This means that it can be used to as a heat source in the winter (and as a source of cooling in the summer).
The temperature of the surface layers of the ground remains fairly constant below a depth of approximately 7-10 m, at the mean ambient air temperature regardless of the time of year. Depending on the location and depth, this temperature is typically between 7C and 13C in the UK. This means that it can be used to as a heat source in the winter (and as a source of cooling in the summer).
A heat pump works by using the evaporation and condensing of a refrigerant to move heat from one place to another. An evaporator (analogous to the loop in the cold part of a fridge) takes heat from water in a ground loop; a condenser (analogous to the hot loop on the back of a fridge) gives up heat to a hot water tank which feeds a distribution system. See ground source heat pumps for more information.
Air-source heat pumps - Air-source heat pumps extract heat from the outside air in a similar way to ground source heat pumps. This can be used to supply heat to radiators, hot air systems or hot water systems.
Air-source heat pumps extract heat from the outside air in a similar way to ground source heat pumps. This can be used to supply heat to radiators, hot air systems or hot water systems.
Water source heat pumps - Water source heat pumps operate on a similar principal but use watercourses as a heat source.
Water source heat pumps operate on a similar principal but use watercourses as a heat source.
Tidal power - Tidal range
Tidal range - Tidal range is the difference in height between high and low tide. Tidal barrages or tidal lagoons can capture the tide, and release it through turbines to generate electricity. Turbine blades can be of a size and speed that allow large fish to freely enter and exit without harm. However, there is concern that enclosing large areas can destroy tidal habitats.
Tidal range is the difference in height between high and low tide. Tidal barrages or tidal lagoons can capture the tide, and release it through turbines to generate electricity. Turbine blades can be of a size and speed that allow large fish to freely enter and exit without harm. However, there is concern that enclosing large areas can destroy tidal habitats.
The Swansea Bay tidal lagoon is calculated to save 216,000 tonnes of CO2 annually which is equivalent to taking 81,000 cars off the road. See tidal lagoons for more information. The UK's total theoretical tidal range resource is estimated to be between 25 and 30 GWs (12% of current UK electricity demand). (Ref. DECC Wave and tidal energy: part of the UK's energy mix)
Tidal stream - Tidal stream is the flow of water resulting from the continual ebb and flood of the tide. Tidal turbines can generate electricity from this flow in a similar way to wind turbines. This is particularly effective in areas where narrow channels or headlands increase the tidal flow.
Tidal stream is the flow of water resulting from the continual ebb and flood of the tide. Tidal turbines can generate electricity from this flow in a similar way to wind turbines. This is particularly effective in areas where narrow channels or headlands increase the tidal flow.
Wave power - Wind blowing across the surface of water causes waves. Wave energy can be captured by a number of methods to power turbines that generate electricity.
Wind blowing across the surface of water causes waves. Wave energy can be captured by a number of methods to power turbines that generate electricity.
Wave and tidal stream energy could meet up to 20% of the UK's current electricity demand. (Ref. DECC Wave and tidal energy: part of the UK's energy mix.)
Hydro electric - Moving water can be used to generate electricity at both large and small scales. The UK generates approximately 1.5% of its electricity is generated by this method, largely by creating dams to capture water and then discharging it through turbines. (Ref. DECC Harnessing hydroelectric power January 2013)
Moving water can be used to generate electricity at both large and small scales. The UK generates approximately 1.5% of its electricity is generated by this method, largely by creating dams to capture water and then discharging it through turbines. (Ref. DECC Harnessing hydroelectric power January 2013)
Wind - Wind energy can be converted into electricity by wind turbines. These can be onshore or offshore, large scale commercial wind farms or small domestic units. Wind energy generation in the UK is growing rapidly, however, wind turbines have proved controversial because of their impact on the landscape and the fact that they only generate electricity 70-85% of the time. (Ref. Renewable UK)
Wind energy can be converted into electricity by wind turbines. These can be onshore or offshore, large scale commercial wind farms or small domestic units. Wind energy generation in the UK is growing rapidly, however, wind turbines have proved controversial because of their impact on the landscape and the fact that they only generate electricity 70-85% of the time. (Ref. Renewable UK)
Biomass - Biomass is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. While both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered 'carbon neutral'. Solid bioenergy options include woodchips and pellets. Using these types of biomass fuel as a heating source is well established across Europe and the UK.
Biomass is a generic term referring to organic materials that can be used as fuels. Biomass differs from fossil fuels because of the timescale required for replacement. While both take carbon out of the environment during their creation, before releasing it when used as a fuel, fossil fuels deplete faster than they are replaced and so are not sustainable whereas biomass can be replaced relatively quickly and so may be considered 'carbon neutral'. Solid bioenergy options include woodchips and pellets. Using these types of biomass fuel as a heating source is well established across Europe and the UK.
Waste - Combustion/incineration
Combustion/incineration - Waste products can be incinerated at around 850C and the energy recovered as electricity or heat.
Waste products can be incinerated at around 850C and the energy recovered as electricity or heat.
Gasification and pyrolysis - Waste fuels can be heated with little or no oxygen present to produce gases which can be used to generate energy.
Waste fuels can be heated with little or no oxygen present to produce gases which can be used to generate energy.
Anaerobic digestion/biogas - Biomass can be broken down by micro-organisms through a process of anaerobic digestion to produce methane-rich biogas that can be used as a fuel. The waste can also be used as a fertiliser.
Biomass can be broken down by micro-organisms through a process of anaerobic digestion to produce methane-rich biogas that can be used as a fuel. The waste can also be used as a fertiliser.
Limitations of renewable energy - A key disadvantage of renewable energy at present lies in the rate at which it can be produced. Despite its successes, renewable energy production remains limited, partly because of the costs of the new technologies required and partly because their efficiency and productivity is partially dependent on variables such as the weather. A study conducted by The Renewable Energy Foundation revealed that the UK has missed its 2010 targets by a 'large margin' (ref. REF, 2011).
A key disadvantage of renewable energy at present lies in the rate at which it can be produced. Despite its successes, renewable energy production remains limited, partly because of the costs of the new technologies required and partly because their efficiency and productivity is partially dependent on variables such as the weather. A study conducted by The Renewable Energy Foundation revealed that the UK has missed its 2010 targets by a 'large margin' (ref. REF, 2011).
Renewable energy may also face the challenge of land constraint. For example, replacing crude oil-derived fuels by bio fuels would require between 1,000 and 10,000 times larger areas for crops than the land used by oil field infrastructures, and shifting from coal-fired to wind-generated electricity would require 10 to 100 times more space (Smil, 2006). Land issues apply to most renewable energies, along with direct or indirect impacts on natural habitats, the visual environment and loss of agricultural land.
These impacts can be seen in countries such as Brazil, Malaysia and Indonesia as producer countries of biofuels and Morocco, Libya, and Jordan where solar power plants are installed.
Nuclear energy - Although some sources claim that Uranium is inexhaustible with 4 billion tons dissolved in sea water, and that it can power the globe for 60,000-years at present rates (Comby, 2008; Fetter, 2009); there are concerns about the current state of available sources and the costs of processing that would be needed to extract uranium from sea water.
Although some sources claim that Uranium is inexhaustible with 4 billion tons dissolved in sea water, and that it can power the globe for 60,000-years at present rates (Comby, 2008; Fetter, 2009); there are concerns about the current state of available sources and the costs of processing that would be needed to extract uranium from sea water.
In addition, radioactive wastes are difficult and costly to dispose of and there is widespread concern about the diversion of nuclear materials to weapons production, as well as nuclear plants' vulnerability to attack. As a consequence, nuclear power may not be seen as a long-term option.
However, increasing C02 emission, rising demand and the limitations of renewable sources creates a dilemma. 'If you don't want nuclear, there are hard choices to be made on other issues' (Fitzgerald, 2005). For the time being at least, the UK government has chosen to support nuclear power as a low-carbon (rather than renewable) source of energy. This may provide some energy security whilst giving time for renewable energy technologies to be perfected.
Incentives - A number of incentives have been introduced by the UK government to encourage the take-up of renewable energy technologies.
A number of incentives have been introduced by the UK government to encourage the take-up of renewable energy technologies.
Feed in tariff - The feed in tariff scheme enables consumers to receive payments from their energy supplier for renewable or low-carbon electricity that they generate, whether they use it themselves, or export surplus back to the grid.
The feed in tariff scheme enables consumers to receive payments from their energy supplier for renewable or low-carbon electricity that they generate, whether they use it themselves, or export surplus back to the grid.
Renewable heat incentive - The renewable heat incentive is a similar scheme to the feed in tariff scheme, but for heat generation. At present it is only available to the non-domestic sector, but the scheme is expected to extend to households in 2014 (ref. Gov.uk Increasing the use of low-carbon technologies).
The renewable heat incentive is a similar scheme to the feed in tariff scheme, but for heat generation. At present it is only available to the non-domestic sector, but the scheme is expected to extend to households in 2014 (ref. Gov.uk Increasing the use of low-carbon technologies).
Green deal - Under the green deal scheme, a 'green deal provider' finances the up-front costs of installing energy efficiency measures, and the consumer's energy supplier adds a 'green deal charge' to the consumer's bill. The range of energy efficiency measures that might qualify under the green deal include (amongst other measures):
Under the green deal scheme, a 'green deal provider' finances the up-front costs of installing energy efficiency measures, and the consumer's energy supplier adds a 'green deal charge' to the consumer's bill. The range of energy efficiency measures that might qualify under the green deal include (amongst other measures):
Wind turbines. - Heat pumps.
Heat pumps. - Thermal and photo voltaic panels.
Thermal and photo voltaic panels. - See Green deal for more information.
See Green deal for more information. -
Climate change levy - The climate change levy (CCL) is a tax chargeable on commercial energy suppliers. Electricity generated from renewable sources is exempt from the climate change levy.
The climate change levy (CCL) is a tax chargeable on commercial energy suppliers. Electricity generated from renewable sources is exempt from the climate change levy.
Site coverage - Land measurement for planning and development purposes, Guidance Note, Global 1st edition, Published by the Royal Institution of Chartered Surveyors (RICS) in May 2021, suggests that: Site coverage (SC) is the ratio of ground floor area (measured on the basis of GEA) to site area.
Land measurement for planning and development purposes, Guidance Note, Global 1st edition, Published by the Royal Institution of Chartered Surveyors (RICS) in May 2021, suggests that: Site coverage (SC) is the ratio of ground floor area (measured on the basis of GEA) to site area.
Site area - The New Rules of Measurement (NRM) are published by the Royal Institute of Chartered Surveyors (RICS). They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects.
The New Rules of Measurement (NRM) are published by the Royal Institute of Chartered Surveyors (RICS). They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects.
According to NRM1: Order of cost estimating and cost planning for capital building work, the term site area (SA) means:
the total area of the site within the site title boundaries (or the total area within the site title boundaries defined by the employer as the site for the building), measured on a horizontal plane.
However, NRM1 then goes on to give a second, slightly different definition:
Where the external works is to be measured separately, the site area (SA) is to be measured. The SA is the total area of the site within the site title boundaries (or the total area within the site title boundaries defined by the employer as the site for the building or buildings), excluding the footprint of the new building(s), measured on a horizontal plane.'
Land measurement for planning and development purposes, Guidance Note, Global 1st edition, Published by the Royal Institution of Chartered Surveyors (RICS) in May 2021, suggests that: Site area is the total land area for which development authorisation is sought, measured on a horizontal plane.
Ecological hazard - A Guide To Climate Change Impacts, On Scotlands Historic Environment, published by Historic Environment Scotland in October 2019, defines an ecological hazard as: A hazard relating to or concerned with living organisms (plant and animal species).
A Guide To Climate Change Impacts, On Scotlands Historic Environment, published by Historic Environment Scotland in October 2019, defines an ecological hazard as: A hazard relating to or concerned with living organisms (plant and animal species).
Glazing ratio - Glazing ratio is: The proportion of glazing to opaque surface in a wall. Also called window-to-wall ratio, it is a key variable in faade design affecting energy performance in buildings.
Glazing ratio is: The proportion of glazing to opaque surface in a wall. Also called window-to-wall ratio, it is a key variable in faade design affecting energy performance in buildings.
Ref Climate Emergency Design Guide: How new buildings can meet UK climate change targets, published by the London Energy Transformation Initiative (LETI) in January 2020.
Global warming potential - Embodied Carbon: Developing a Client Brief, published by the UK Green Building Council (UKGBC) in March 2017, defines Global Warming Potential (GWP) as: a relative measure of how much a given mass of greenhouse gas is estimated to contribute to global warming over a given time interval. It is expressed relative to carbon dioxide which has a GWP of 1. These factors are regularly updated, and it is recommended to use the latest factors from the Intergovernmental Panel on Climate Change (IPCC). Most assessments adopt GWP factors over a 100 year-time horizon.
Embodied Carbon: Developing a Client Brief, published by the UK Green Building Council (UKGBC) in March 2017, defines Global Warming Potential (GWP) as: a relative measure of how much a given mass of greenhouse gas is estimated to contribute to global warming over a given time interval. It is expressed relative to carbon dioxide which has a GWP of 1. These factors are regularly updated, and it is recommended to use the latest factors from the Intergovernmental Panel on Climate Change (IPCC). Most assessments adopt GWP factors over a 100 year-time horizon.
GWP of principal greenhouse gases over 100 years excluding climate-carbon feedbacks
Greenhouse Gas GWP Typical sources - Carbon dioxide (CO2) 1 Energy combustion, biochemical reactions
Carbon dioxide (CO2) 1 Energy combustion, biochemical reactions
Methane (CH4) 28 Decomposition - Nitrous oxide (N2O) 265 Fertilisers, car emissions, manufacturing
Nitrous oxide (N2O) 265 Fertilisers, car emissions, manufacturing
Ref IPCC, 2013. Climate Change 2013: The Physical Science Basis. Contribution of Working Group 1 to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Table 8.7.
Carbon neutral buildings - The Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018 defines carbon neutral as:
The Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018 defines carbon neutral as:
Carbon neutral means that, through a transparent process of calculating building operational emissions, reducing those emissions and offsetting residual emissions, net carbon emissions equal zero. This includes carbon emissions from both regulated and unregulated energy consuming plan and systems. Also see the definition of zero net regulated carbon (CO) emissions.
--BRE Group -
NB The impact of sustainability on value published by JLL in March 2020 defines carbon neutral as: offsetting emissions with payments either to avoid a reduction in emissions or remove carbon from the atmosphere.
The London Plan, Published by the Mayor of London in March 2016, defines carbon neutrality as: Contributing net zero carbon dioxide emissions to the atmosphere.
Layout - The Town and Country Planning (Development Management Procedure) (England) Order 2015 defines layout as: the way in which buildings, routes and open spaces within the development are provided, situated and orientated in relation to each other and to buildings and spaces outside the development
The Town and Country Planning (Development Management Procedure) (England) Order 2015 defines layout as: the way in which buildings, routes and open spaces within the development are provided, situated and orientated in relation to each other and to buildings and spaces outside the development
Joint - In its broadest sense, the word 'joint' refers to the fitting together of two or more parts.
In its broadest sense, the word 'joint' refers to the fitting together of two or more parts.
In the construction industry this might relate to:
Concrete joint. - Construction joint.
Construction joint. - Contraction joint.
Contraction joint. - Crack control joint.
Crack control joint. - Daywork joint.
Daywork joint. - Dowelled joint.
Dowelled joint. - Expansion joint.
Expansion joint. - Finger joint.
Finger joint. - Joggle joint.
Joggle joint. - Joint v connection.
Joint v connection. - Mortar joint.
Mortar joint. - Mortise and tenon joint.
Mortise and tenon joint. - Movement joint.
Movement joint. - Scarf joint.
Scarf joint. - Shrinkage joint.
Shrinkage joint. - Tongue and groove joint.
Tongue and groove joint. - Warping joint.
Warping joint. -
Heat loss - Heat is the energy that is transferred between different systems as a result of thermodynamic interactions.
Heat is the energy that is transferred between different systems as a result of thermodynamic interactions.
Heat loss is a measure of negative heat transfer through a buildings fabric from the inside to the outside. This can be due to either convection, conduction, radiation, mass transfer, or a combination. The colder the outside temperature, the warmer the inside, and the worse the thermal insulation of the building fabric, the greater the heat loss will be.
Heat loss is typically measured in either kilowatts (kW) or British Thermal Units (BTUs).
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a building's fabric are at insulating against heat loss (or heat gain). The lower the U-value of an element of a building's fabric, the more slowly heat is able to transmit through it, and so the better it performs as an insulator. Very broadly, the better (i.e. lower) the U-value of a building's fabric, the less energy is required to maintain comfortable conditions inside the building.
The building regulations require that reasonable provision be made to limit heat gains and losses through the fabric of new buildings and works to existing buildings. The approved documents to the buildings regulations set out the limiting standards for the properties of the fabric elements of the building, described in terms of maximum U-values. For more information see: Limiting fabric standards.
Typically, the older a building is, the more it will be susceptible to heat loss. This can be due to a combination of poor (or no) insulation, thermal bridging across the building envelope, single glazing, poor airtightness and so on,
Levels of heat loss will vary depending on the type of building; for example, a terraced house will lose a higher proportion of heat through the floor and roof rather than walls, whilst nearly all the heat loss from a flat will be through the outside walls.
The following estimates indicate the proportionate heat loss from a badly insulated house:
Up to 25% through the roof. - Up to 35% through outside walls.
Up to 35% through outside walls. - Up to 25% through doors and windows.
Up to 25% through doors and windows.
Up to 15% through ground floors. -
Overheating in buildings - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Design causes of overheating
2 Design causes of overheating - 3 How to deal with overheating
3 How to deal with overheating - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - 5 External references
5 External references - Introduction
Introduction - The term 'overheating' refers to discomfort to occupants caused by the accumulation of warmth within a building. It is considered to be a growing problem in the UK due to climate change, the urban heat island effect, electronic equipment, increasing amounts of glazing and so on.
The term 'overheating' refers to discomfort to occupants caused by the accumulation of warmth within a building. It is considered to be a growing problem in the UK due to climate change, the urban heat island effect, electronic equipment, increasing amounts of glazing and so on.
CIBSE define overheating as: 'conditions when the comfortable internal temperature threshold of 28C is surpassed for over 1% of the time.' They also define 35C as the internal temperature above which there is a significant danger of heat stress.
In 2006, the Trades Union Congress (TUC) stated that it believed a maximum temperature of 30C should be set, or 27C for those doing strenuous work. In July 2019, the Labour party proposed the same maximum workplace temperature of 30C, or 27C for those doing strenuous work. They tasked a proposed Royal Commission on Health and Safety at Work with bringing forward proposals.
For more information see: Heat stress. -
Overheating can result in serious health issues, particularly amongst the elderly or young children. The summer heat wave of 2003 recorded an increase of 2,000 deaths in the UK due to heat exposure. It is predicted that by the 2080s this figure could have risen to as much as 5,000.
Design causes of overheating - Some of the reasons for overheating are thought to be modern building fabric standards that aim to keep buildings warm in colder climates. The House Builder's Association have been reported as saying that 'the ever exacting standards' of Building Regulations Part L cause overheating by stipulating airtightness levels that are too high.
Some of the reasons for overheating are thought to be modern building fabric standards that aim to keep buildings warm in colder climates. The House Builder's Association have been reported as saying that 'the ever exacting standards' of Building Regulations Part L cause overheating by stipulating airtightness levels that are too high.
Overheating may be caused by a single predominant factor or as a cumulative effect of different factors. These include:
Solar radiation passes through glass and heats internal surfaces, which re-radiate long wave infra-red radiation that cannot pass through glass. This is known as the greenhouse effect.
Double-glazed windows reduce heat losses through conduction. - Increasingly high levels of insulation reduce heat transmission across the building fabric.
Increasingly high levels of insulation reduce heat transmission across the building fabric.
The activities of occupants such as cooking, bathing, showering all generate heat. Electrical appliances generate heat when in use.
Occupants themselves generate heat, the amount of which is dependent on their activity level.
If a site is in close proximity to airborne noise, pollution or odour from busy roads, railways or industrial sites, occupants will be reluctant to open windows and so heat will accumulate inside.
Urban heat island effect is primarily caused by the replacement of natural surfaces with hard impervious surfaces that are generally dark and absorb large amounts of solar radiation. Urban hard surfaces are significant in the built environment in the form of roads, paved areas, roof tops and so on.
Buildings oriented with south facing glazing may accumulate high levels of solar gain.
Overheating problems may be contributed to by heat gain from boilers, hot water storage and distribution and other building services systems. This can be a particular problem in apartment buildings that have community heating pipework.
Increasing levels of airtightness can reduce the amount of 'fresh' air entering a building.
How to deal with overheating - Orientation and footprint can be designed to minimise solar gain and maximise opportunities for cross ventilation, stack ventilation and so on.
Orientation and footprint can be designed to minimise solar gain and maximise opportunities for cross ventilation, stack ventilation and so on.
High-performance glazing such as low-e glass, smart glass and so on can reduce heat gains. Smart glazing can be manually or automatically adjusted to control the amount of light, glare or heat that passes through. Whilst the price is decreasing it is still a very expensive option and as such is most likely to be found in commercial developments.
Adjustable blinds can allow some internal control over solar gains.
External shading such as canopies, louvres and shutters may help to prevent overheating. Intelligent facades can give control over climate exposure.
Glazing ratio: Large expanses of glazing increase solar gain and make a building more susceptible to overheating. However, large windows also admit natural light. Glazing ratios try to achieve an equilibrium between these two positions.
Urban heat island - The Urban Heat Island (UHI) effect is the term given to localised higher temperatures that are experienced in urban environments compared with the temperatures of surrounding green spaces (Akbari and Konopacki 2005).
The Urban Heat Island (UHI) effect is the term given to localised higher temperatures that are experienced in urban environments compared with the temperatures of surrounding green spaces (Akbari and Konopacki 2005).
The Urban Heat Island effect is primarily caused by the replacement of natural surfaces with hard impervious surfaces that are generally dark and absorb large amounts of solar radiation. Urban hard surfaces are significant in the built environment in the form of roads, paved areas, and roof tops (Getter, Rowe et al. 2007).
It is estimated that pavements and roofs account for 60% of urban surfaces, roofs 20-25% and pavements approximately 40% (Akbari, Menon et al. 2009). Presently these surfaces have relatively low albedo values (the fraction of incoming radiation reflected by a body) and high thermal conductivities, typically absorbing and re-radiating around 90% of the total incident solar radiation (Wolf and Lundholm 2008). This contributes to an Urban Heat Island effect that can result in a rise in summer temperatures of 4-7C (CIBSE 2007; Wolf and Lundholm 2008) in comparison with adjacent vegetated areas.
This has a significant impact on thermal comfort in city environments. During a summer heatwave in the UK employers lost an estimated 168 million per day in productivity in one week (Roberts 2008).
In addition to this, heat islands are an energy efficiency concern due to increased air conditioning requirements which raise energy consumption, peak electricity demand and energy prices (Synnefa, Santamouris et al. 2007). Typically, electricity use in cities increases 2-4% for every temperature increase of one degree Celsius (Akbari, Pomerantz et al. 2001) . These costs are likely to increase further if global temperatures rise and increasing urbanisation makes the Urban Heat Island effect more significant.
Hotter urban environments will lead to an increase in the use of air conditioning. It follows that there will be a further increase in city temperatures from the dumping of heat from buildings heating ventilation and air conditioning (HVAC) systems and so more air cooling will be required (Takakura, Kitade et al. 2000). In other words, this process could be described as a vicious circle or negative reinforcing loop. There will also be an impact from increased emissions from cooling if this cooling is provided by fossil fuel based electricity. This will lead to an increased rate of global warming.
Successfully modelling the Urban Heat Island effect is an ongoing process. In the UK this research is looking at the effect in London and is been investigated by University College London (UCL). Their work under the LUCID project is looking at how to develop a Local Urban Climate Model and apply it to the Intelligent Design of Cities.
Greenhouse gases - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Gas concentrations in the atmosphere
2 Gas concentrations in the atmosphere - 3 Sources of greenhouse gases from human activity (anthropogenic)
3 Sources of greenhouse gases from human activity (anthropogenic)
4 Legislation and policy - 4.1 Setting national policy and strategy
4.1 Setting national policy and strategy - 4.2 Reducing energy demand and helping people to use energy efficiently
4.2 Reducing energy demand and helping people to use energy efficiently
4.3 Investing in low carbon technologies - 4.4 Public reporting
4.4 Public reporting - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - 6 External references
6 External references - Introduction
Introduction - Greenhouse gases are gases that are relatively transparent to short-wave infrared radiation (such as heat from the sun). This means that they allow sunlight to enter the atmosphere and heat the Earths surfaces. These surfaces then re-radiate that heat as long-wave infrared radiation, which greenhouse gases tend to absorb rather than transmit.
Greenhouse gases are gases that are relatively transparent to short-wave infrared radiation (such as heat from the sun). This means that they allow sunlight to enter the atmosphere and heat the Earths surfaces. These surfaces then re-radiate that heat as long-wave infrared radiation, which greenhouse gases tend to absorb rather than transmit.
The result is that the long-wave infrared radiation is trapped and heat accumulates in the atmosphere causing a warming process. This process is known as the greenhouse effect because it is similar to the effect that glass has, trapping heat in greenhouses.
The four main greenhouse gases are: -
Water vapour. - Carbon dioxide.
Carbon dioxide. - Methane.
Methane. - Nitrous oxide.
Nitrous oxide. - Ozone and chlorofluorocarbons (CFCs) are also greenhouse gases.
Ozone and chlorofluorocarbons (CFCs) are also greenhouse gases.
The main constituents of the atmosphere; nitrogen, oxygen and argon, are not greenhouse gases.
Gas concentrations in the atmosphere - Greenhouse gases are necessary in the atmosphere to maintain a stable temperature for life to exist and it is usual for the gas concentrations to fluctuate. These changes are generally slow, with average global air temperature varying over a period of hundreds of thousands or millions of years, and this slow rate of change allows life on earth to adapt. However, over the last 150 years the rate of increase has been significantly higher than normal, resulting in a relatively fast increase in average global air temperatures.
Greenhouse gases are necessary in the atmosphere to maintain a stable temperature for life to exist and it is usual for the gas concentrations to fluctuate. These changes are generally slow, with average global air temperature varying over a period of hundreds of thousands or millions of years, and this slow rate of change allows life on earth to adapt. However, over the last 150 years the rate of increase has been significantly higher than normal, resulting in a relatively fast increase in average global air temperatures.
The concentrations of greenhouse gases in the atmosphere are the result of the balance between sources (human activities and natural systems) and sinks (removal of the gas from the atmosphere through natural processes or negative emissions, such as carbon capture) (ref. Intergovernmental Panel on Climate Change (IPCC) 2013).
Measurements of atmospheric carbon dioxide began in 1958 and these have revealed the full impact of human activities from the natural annual cycle of the biosphere. Since 1970, increased concentrations of methane and nitrous oxide have also been detected. Between 1999 and 2006, the levels of methane stabilised, but increases were detected again in 2007. The increase in greenhouse gases is a key indicator of global climate change.
Sources of greenhouse gases from human activity (anthropogenic)
There are a number of human activities that result in increases in greenhouse gases in the atmosphere, including:
Burning fossil fuels. - Deforestation.
Deforestation. - Livestock enteric fermentation.
Livestock enteric fermentation. - Paddy fields and land use changes.
Paddy fields and land use changes. - Use of chlorofluorocarbons (CFCs).
Use of chlorofluorocarbons (CFCs). - Agricultural activities, including the use of fertilizers.
Agricultural activities, including the use of fertilizers.
It is considered likely that the increased atmospheric concentrations of greenhouse gases from human activities and the resulting warming will have a wide range of effects including; an increase in extreme weather events, sea level rise, loss of biodiversity and variation in agricultural productivity.
Legislation and policy - The establishment of the Climate Change Act 2008 committed the UK to reducing greenhouse gases by at least 80% by 2050 (from the 1990 baseline).
The establishment of the Climate Change Act 2008 committed the UK to reducing greenhouse gases by at least 80% by 2050 (from the 1990 baseline).
The Committee on Climate Change was formed following the 2008 act to assess how the UK could help meet the reduction targets. It proposed that the reduction will be achieved through a suite of methods:
Setting national policy and strategy - Setting carbon budgets for limiting UK greenhouse gas emissions.
Setting carbon budgets for limiting UK greenhouse gas emissions.
Undertaking further research to inform climate change policy.
Using the EU Emissions Trading Scheme to help deliver reductions.
Ensuring project and policy appraisals calculate accurate carbon amounts.
Reducing energy demand and helping people to use energy efficiently
Reducing energy demand with meters and other energy efficient measures.
Reducing emissions by improving energy efficiency of properties through the Green Deal.
Providing incentives for organisations to take up energy-efficient technologies and practices through the government Carbon Reduction Commitment Energy Efficiency Scheme.
Reducing emissions from transport and agriculture. - Investing in low carbon technologies
Investing in low carbon technologies - Creating an industry for carbon capture and storage.
Creating an industry for carbon capture and storage.
Reforming the UKs electricity market. - Provision of over 200 million for innovation in low carbon technology.
Provision of over 200 million for innovation in low carbon technology.
Public reporting - Measuring and reporting environmental impacts (Defra, 2013).
Measuring and reporting environmental impacts (Defra, 2013).
Asking local authorities to measure and report their greenhouse gas emissions.
(Ref. Department of Energy and Climate Change (DECC), 2014.)
NB: On 15 October 2016 it was announced that 170 countries in Kigali, Rwanda, had agreed that all HFCs should be phased out through an amendment to the Montreal Protocol. See HFC phase out for more information.
Fossil fuel - Fuels280.jpg
Fuels280.jpg -
Fossil fuels are types of non-renewable fuels formed by over millions of years by the anaerobic decomposition of organisms buried beneath or within soil and rock. They are considered to be non-renewable because the rate at which they are currently consumed is far in excess of the rate at which they are naturally replaced, and so they are being rapidly depleted.
Fossil fuels include: -
Coal. - Petroleum.
Petroleum. - Natural gas.
Natural gas. - Oil shale.
Oil shale. - Bitumen.
Bitumen. - Tar sand.
Tar sand. - Fossil fuels, contain energy that originated in photosynthesis. They can be burnt in air, or oxygen, to provide heat, which can be used directly, or converted into energy such as electricity. The Industrial Revolution drastically increased the consumption of fossil fuels to the contemporaneous point where levels are widely considered to be unsustainable, hence the drive for large-scale up-take of renewable energy sources.
Fossil fuels, contain energy that originated in photosynthesis. They can be burnt in air, or oxygen, to provide heat, which can be used directly, or converted into energy such as electricity. The Industrial Revolution drastically increased the consumption of fossil fuels to the contemporaneous point where levels are widely considered to be unsustainable, hence the drive for large-scale up-take of renewable energy sources.
Types of fossil fuel extraction, such as shale gas, have intensified the debate over whether or not modern and intensive methods should be employed for the further exploitation of non-renewable energy sources.
Burning fossil fuels produces carbon dioxide (and other pollutants) which is a greenhouse gas and so contributes to climate change.
NB Climate Emergency Design Guide: How new buildings can meet UK climate change targets, published by the London Energy Transformation Initiative (LETI) in January 2020, defines a fossil fuel as: 'A natural fuel such as petroleum, coal or gas, formed in the geological past from the remains of living organisms. The burning of fossil fuels by humans is the largest source of emissions of carbon dioxide, which is one of the greenhouse gases that allows radiative forcing and contributes to global warming.
Power generation - Electricity-3442835 640.jpg
Electricity-3442835 640.jpg -
The term 'power generation' describes the process of generating electrical power. Types of power generation include:
Fossil fuel thermal energy such as coal or natural gas.
Biogas energy. - Geothermal energy.
Geothermal energy. - Hydroelectricity.
Hydroelectricity. - Wind energy.
Wind energy. - Solar thermal energy.
Solar thermal energy. - Tidal energy.
Tidal energy. - Photovoltaics.
Photovoltaics. - Nuclear energy.
Nuclear energy. - Chemical energy generated from fuel cells, batteries, and so on.
Chemical energy generated from fuel cells, batteries, and so on.
Power stations are normally located away from centres of population where fossil fuels are abundant or good transport links exist. Many of these locations are well away from the towns and cities where the electricity is used and hence there is a need for electricity transmission and distribution.
The national power supply network is managed by four types of organisation:
Generators - responsible for producing the electricity. - Suppliers - responsible for supply and selling electricity to consumers.
Suppliers - responsible for supply and selling electricity to consumers.
Transmission network - responsible for the transmission of electricity across the country.
Distributors - those who own and operate the local distribution network from the national transmission network to homes and businesses.
Microgeneration is the local production of power on a very small scale in comparison to the typical output of a power station.
Consumers can qualify for an export tariff by selling surplus electricity back to their supplier. Allowable technologies are:
Solar photovoltaic panels. - Wind turbines.
Wind turbines. - Water turbines.
Water turbines. - Anaerobic digestion (biogas energy).
Anaerobic digestion (biogas energy). - Micro combined heat and power (micro-CHP).
Micro combined heat and power (micro-CHP).
NB Net Zero by 2050, A Roadmap for the Global Energy Sector, published by the International Energy Agency in May 2021, suggests that power generation: Refers to fuel use in electricity plants, heat plants and combined heat and power (CHP) plants. Both main activity producer plants and small plants that produce fuel for their own use (auto-producers) are included.
Solar photovoltaics - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Transforming sunlight to electricity
2 Transforming sunlight to electricity - 3 Photovoltaic cells
3 Photovoltaic cells - 4 Using the energy from photovoltaics
4 Using the energy from photovoltaics - 5 Photovoltaic installation
5 Photovoltaic installation - 6 Planning and Regulation
6 Planning and Regulation - 7 Government Funding
7 Government Funding - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - 9 External references
9 External references - Introduction
Introduction - Solar cells, or photovoltaic (PV) cells, convert sunlight directly into electricity. Photovoltaics gets its name from the process of converting light (photons) to electricity (voltage). Photovoltaic panels are quite different to solar thermal panels that capture the sun's heat to produce hot water, although some panels now combine both a PV array and a solar thermal collectors.
Solar cells, or photovoltaic (PV) cells, convert sunlight directly into electricity. Photovoltaics gets its name from the process of converting light (photons) to electricity (voltage). Photovoltaic panels are quite different to solar thermal panels that capture the sun's heat to produce hot water, although some panels now combine both a PV array and a solar thermal collectors.
Rigid photovoltaic cells (traditionally made of silicon) are generally approximately 150mm square and produce a small amount of electricity (at about 05 volts). This means that in order to generate a higher voltage, a large number of cells, typically 36 or 72, are connected in series to form a photovoltaic panel. The panels are then connected together to create a photovoltaic array. Generally an array will consist of around 10 panels for a domestic application.
Thin film solar cells use layers of semiconductor materials a few microns thick. Being semi-flexibile they can be used as part of building elements such as roof tiles and glazing systems. New technologies are producing solar cells applied by printing press technologies using solar dyes, and integrated with conductive plastics.
The estimated lifetime of a photovoltaic module is 30 years and performance would be expected to remain at over 80% of the initial power after 25 years.
The carbon footprint of manufacturing photovoltaic has decreased by approximately 50% in the last 10 years due to performance improvements, raw material savings and manufacturing process improvements.
Transforming sunlight to electricity - Solar panels are rated in terms of peak power (kWp). This is the potential power output in bright sunlight (1000W/m) and an air temperature of 25 C (the output of panels reduces as they increase in temperature). 1 kWp of well-sited photovoltaic array in the UK should be able to produce 700-800 kWh of electricity per year.
Solar panels are rated in terms of peak power (kWp). This is the potential power output in bright sunlight (1000W/m) and an air temperature of 25 C (the output of panels reduces as they increase in temperature). 1 kWp of well-sited photovoltaic array in the UK should be able to produce 700-800 kWh of electricity per year.
The amount of incident solar radiation will depend on the latitude of the site, the direction that the panels face and the panels tilt angle. An online calculator is available for obtaining estimates of the potential generated energy for sites in Europe (ref EU Joint Research Centre). Even on cloudy days the resulting diffuse light will provide useful electricity, however the performance will be reduced if the site is regularly shaded (for example by adjacent buildings or vegetation).
Photovoltaic cells - There are three principal types of photovoltaic cell. Their individual percentage efficiencies indicate how much of the incoming solar radiation will convert into electricity leaving the cell (there will be further losses in the control systems and cabling):
There are three principal types of photovoltaic cell. Their individual percentage efficiencies indicate how much of the incoming solar radiation will convert into electricity leaving the cell (there will be further losses in the control systems and cabling):
Monocrystalline: Typical efficiency of 15% (about 100kWh per m per year in the UK). These are typically dark coloured with close lines of thin conductors.
Polycrystalline: Typical efficiency of at least 13% (around 100kWh per m per year in the UK). These are likely to have a truly crystalline appearance.
Thin film: Typical efficiency of 7% (about 60kWh per m per year in the UK). These may be integrated onto brise-soleil, roof tiles or glass panels.
Crystalline photovoltaics currently account for over 90% of installed systems.
The cost of the materials is generally highest for the more efficient types of cell although the integration of thin-film technologies into building elements adds to their cost.
Using the energy from photovoltaics - Photovoltaics can power systems that are totally disconnected from the grid (particularly in rural locations) however the surge in interest in UK applications is for grid-connected systems that are eligible for government funding. This allows any excess power produced to be sold to the electrical supply company, and provides a normal grid supply to the premises when there is insufficient photovoltaic generation.
Photovoltaics can power systems that are totally disconnected from the grid (particularly in rural locations) however the surge in interest in UK applications is for grid-connected systems that are eligible for government funding. This allows any excess power produced to be sold to the electrical supply company, and provides a normal grid supply to the premises when there is insufficient photovoltaic generation.
Photovoltaic installation - There is relatively little mechanical work associated with the installation of photovoltaic panels, and there is a mature market for the supply of flexible mounting systems. However, there is controlled work that requires properly trained electricians, and installation of roof-mounted panels would normally require a trained 'roofing' installer. Photovoltaic modules generate electricity whenever they are exposed to daylight and individual modules cannot be switched off so, unlike most other electrical installations, installing a photovoltaic system involves working on a live system.
There is relatively little mechanical work associated with the installation of photovoltaic panels, and there is a mature market for the supply of flexible mounting systems. However, there is controlled work that requires properly trained electricians, and installation of roof-mounted panels would normally require a trained 'roofing' installer. Photovoltaic modules generate electricity whenever they are exposed to daylight and individual modules cannot be switched off so, unlike most other electrical installations, installing a photovoltaic system involves working on a live system.
Typical installations of photovoltaic modules will weigh 1013 kg/m.The main types of installation are:
Roof or wall mounting of framed photovoltaics. The photovoltaics are mounted in framing that should generally protrude less than 200mm to satisfy normal planning requirements.
Roof or wall-integrated photovoltaics, where the panel is a weathered section of the surface.
Roof slates and tiles. These will be more expensive as individual components but may reduce expenditure by displacing standard tiles/slates.
Surface-mounted (thin-film) photovoltaics. Semi-flexible thin-film photovoltaics are attached to a building component such as a glass panel or flat roof.
Framed installations (freestanding or attached to building). Plastic or metal frames can sit on roofs or on the ground to provide optimum tilt and orientation.
More recent developments have led to a variety of forms of integrated solar collector, including:
Solar shingles mounted flat on boarded roofs. - Solar slates mounted on battens that can replace standard roof components.
Solar slates mounted on battens that can replace standard roof components.
Solar glass laminates, where the photovoltaics take the form of semi-transparent glazing.
These can offer opportunities to include photovoltaics in a project where, previously, aesthetic considerations would have prevented their use.
In a grid connected system, DC power from the photovoltaic modules is fed into an inverter for conversion to 240 V AC power for connection to the local electricity network through the consumer unit. Ideally, the inverter (or 'power control unit') will be sited close to the panels to reduce DC transmission losses (it needs ventilation and may hum). In larger applications several inverters may be used to provide improved resilience against failure. The inverter unit will normally control the connection of the photovoltaic system to the grid (as well as to the building loads). If there is a mains power outage the inverters automatically switch off to protect any engineers working on the power lines.
In off-grid systems the DC power is fed into a charge controller before being supplied to a storage medium, such as lead acid batteries. A grid-connected solar photovoltaic system requires no batteries. Specialised solutions may be used to provide hybrid systems allowing grid-based systems to work safely off-grid (in combination with batteries), but normally, systems designed for the grid are not usable directly with battery storage.
Photovoltaic systems do not generally require special precautions for lightning protection although taking precautions against lightning and excess voltage may be advisable to protect the investment in the photovoltaics.
A recent report from the International Energy Agency (IEA) Photovoltaic Power Systems Programme set out the life expectancy of equipment associated with a photovoltaic installations:
Photovoltaic panels: 30 years for mature module technologies.
Inverters: 15 years for small plants (residential photovoltaics).
Structures: 30 years for roof-tops and faades, and between 30 to 60 years for ground mounted installations on metal supports.
Cabling: 30 years. - The BRE's UK Photovoltaic Domestic Field Trial in 2006 showed that for fairly small system sizes of around 1.6kWp, a significant fraction of the building demand can be met by the photovoltaic system with the majority of systems providing between 20 and 80% of the building annual load, with an average of 51%.
The BRE's UK Photovoltaic Domestic Field Trial in 2006 showed that for fairly small system sizes of around 1.6kWp, a significant fraction of the building demand can be met by the photovoltaic system with the majority of systems providing between 20 and 80% of the building annual load, with an average of 51%.
Planning and Regulation - In the UK, fixing solar panels to a single dwelling house that is not a listed building and is not in a conservation area is considered to be a 'permitted development' and so there is no need to apply for planning permission. Photovoltaic installations are however notifiable for building regulations purposes and the local building control authority should be informed.
In the UK, fixing solar panels to a single dwelling house that is not a listed building and is not in a conservation area is considered to be a 'permitted development' and so there is no need to apply for planning permission. Photovoltaic installations are however notifiable for building regulations purposes and the local building control authority should be informed.
The District Network Operator (DNO) must be consulted about connection to the local grid (and an agreement put in place) although normally systems of up to 16 amps per phase can be installed without asking permission of the DNO. Extensive guidance on the electrical requirements is given in the DTI publication: Photovoltaics in buildings: guide to the installation of PV systems.
The Microgeneration Certification Scheme (MCS) has provided Microgeneration Installation Standard: MIS 3002 that guides the design and installation of photovoltaics. This is essential if government funding is being sought for a project of less than 50kW and provides a useful source of information for larger installations.
Government Funding - Photovoltaic installations are recognised as a small-scale (less than 5MW) 'renewable energy' technology by the UK Government. As such they attract Feed in Tariff payments (FITs) for installations up to 5MW for a duration of 25 years. Microgeneration systems (less than 50kW) must be installed under the auspices of the MCS to attract funding.
Photovoltaic installations are recognised as a small-scale (less than 5MW) 'renewable energy' technology by the UK Government. As such they attract Feed in Tariff payments (FITs) for installations up to 5MW for a duration of 25 years. Microgeneration systems (less than 50kW) must be installed under the auspices of the MCS to attract funding.
Feed in Tariffs consist of 2 elements: -
Generation tariff. A payment for each unit (kWh) of electricity generated.
Export tariff. Electricity that is not used on site can be exported back to the grid and a payment is paid as an additional payment (on top of the generation tariff).
If photovoltaics are installed and the property owner/operator receives Feed in Tariffs, and subsequently the property is passed to another owner, the Feed in Tariffs will remain with the installation and accrue to the new owner.
If a business has photovoltaics installed and is already involved in the Carbon Reduction Commitment (CRC) Energy Efficiency Scheme the output from photovoltaic systems (that are registered for Feed in Tariffs) will not be counted as 'zero emission' for CRC purposes but must be accounted for at the grid average. To use photovoltaics to gain CRC credit, Feed in Tariffs cannot be claimed. Detailed guidance on the Feed in Tariff scheme for businesses is available in some clearly written fact sheets on the Carbon Trust website.
Warehouse - Forklift-warehouse-835340 640.jpg
Forklift-warehouse-835340 640.jpg -
The term warehouse generally refers to a large building that can be used to store raw materials or manufactured goods prior to distribution or sale.
Retail warehouses are large, single-level stores, typically with a minimum of 1,000 square metres gross retail floorspace, normally selling goods for home improvement or gardening, furniture, electrical goods, carpets and so on. They are most commonly found in the fringe of towns or in out of town locations.
For more information see: Retail warehouse. -
Warehouse management systems (WMS) can be used to reduce delivery lead times and errors while processing orders.
For more information see: Warehouse management systems.
Carbon dioxide in construction - Carbon.jpg
Carbon.jpg - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Climate Change Act
2 Climate Change Act - 3 Uses in construction
3 Uses in construction - 3.1 Sustainable materials
3.1 Sustainable materials - 3.2 Waste management
3.2 Waste management - 3.3 Transportation
3.3 Transportation - 3.4 Other strategies
3.4 Other strategies - 4 Energy consumption
4 Energy consumption - 5 Carbon capture and storage
5 Carbon capture and storage - 6 Related articles on Designing Buildings Wiki
6 Related articles on Designing Buildings Wiki - Introduction
Introduction - Carbon dioxide is a naturally-occurring gas that is integral to life and characterised by being colourless and odourless. Its chemical formula is CO2, made up of a carbon atom which is covalently double-bonded to two oxygen atoms.
Carbon dioxide is a naturally-occurring gas that is integral to life and characterised by being colourless and odourless. Its chemical formula is CO2, made up of a carbon atom which is covalently double-bonded to two oxygen atoms.
In the Earths atmosphere, carbon dioxide exists at a concentration of around 0.04% (400 ppm) by volume. Carbon dioxide is released into the atmosphere by dissolution from carbonate rocks, volcanoes, hot springs and geysers, as well as occurring in groundwater, glaciers, oceans, rivers and lakes. In addition, all aerobic organisms produce carbon dioxide when respiring and plants and trees take in carbon dioxide and produce oxygen. The term 'biogenic carbon' refers to:'Emissions are those that originate
from biological sources such as plants, trees, and soil.' ref Climate Emergency Design Guide: How new buildings can meet UK climate change, published by The London Energy Transformation Initiative (LETI) in January 2020.
Carbon dioxide is a greenhouse gas and the increase in the burning of carbon-based fossil fuels, as well as increasing deforestation, since the Industrial Revolution, is leading to higher rates of global warming as a result of more carbon being concentrated in the atmosphere.
Greenhouse gases are relatively transparent to short-wave infrared radiation (such as heat from the sun). This means that they allow sunlight to enter the atmosphere and heat the Earths surface. These surfaces then re-radiate that heat as long-wave infrared radiation, which greenhouse gases tend to absorb rather than transmit. The result is that the long-wave infrared radiation is trapped and heat accumulates in the atmosphere causing a warming process. This process is known as the greenhouse effect because it is similar to the effect that glass has, trapping heat in a greenhouse.
Despite some uncertainty regarding the severity of the temperature response to a given increase in carbon dioxide in the atmosphere, there is a general consensus that:
The earths climate has always changed over timescales ranging from thousands of years to millennia;
Greenhouse gases from human activity are warming the world (anthropogenic);
Effort is needed to reduce emissions and to adapt to the changes that are likely to occur from the gases already in the atmosphere.
Climate Change Act - The Climate Change Act 2008 established a legally binding target to reduce the UKs greenhouse gas emissions by at least 80% below 1990 year levels by 2050.
The Climate Change Act 2008 established a legally binding target to reduce the UKs greenhouse gas emissions by at least 80% below 1990 year levels by 2050.
To drive progress, the Act introduced a system of carbon budgets which provide legally binding limits on the amount of emissions that may be produced in successive five-year periods:
2008-2012, 23% reduction below 1990 levels.
2013-2017, 29% reduction below 1990 levels.
2018-2022, 35% reduction below 1990 levels.
2023-2027, 50% reduction below 1990 levels.
Uses in construction - There are a number of direct uses of carbon dioxide by the construction industry:
There are a number of direct uses of carbon dioxide by the construction industry:
Carbon dioxide is one of the most commonly used compressed gases for pneumatic systems (pressurised gas) in portable pressure tools that are ubiquitous in the construction industry;
MIG/MAG welding uses carbon dioxide as an atmosphere, as a means of protecting the weld puddle from the surrounding air and oxidizing. When mixed with argon, a higher welding rate can be achieved which often reduces the need for post-weld treatment. In manufacturing casting moulds, carbon dioxide helps to ensure their hardness and rigidity, and
Carbon dioxide is also used to create dry ice pellets which can be used to replace sandblasting for removing paint from surfaces.
However, more significantly, there are considerable emissions of carbon dioxide as a result of activities to construct and then operate built assets.
According to the Technology Strategy Board, the construction, operation and maintenance of the built environment accounts for 45% of total UK carbon emissions (27% from domestic buildings and 18% from non-domestic buildings).
The UK Green Building Council says that around 10% of the UKs carbon dioxide emissions are directly associated with construction. This includes the CO2 generated through the entire building process:
Extraction - Manufacturing (including the energy to manufacture capital equipment, heating and lighting of factories)
Manufacturing (including the energy to manufacture capital equipment, heating and lighting of factories)
Transportation - Construction
Construction - Maintenance
Maintenance - Disposal.
Disposal. - In order to meet emissions targets, the construction industry has been trying to adopt various strategies to reduce the level of CO2 that is produced during construction. Some of these strategies include:
In order to meet emissions targets, the construction industry has been trying to adopt various strategies to reduce the level of CO2 that is produced during construction. Some of these strategies include:
Sustainable materials - Optimising the use of less polluting materials is an important way of cutting embedded carbon in new buildings. Around half of all CO2 emissions in the industry are from cement production, both in the manufacturing process and as a by-product of the chemical reactions. Low-carbon cements are available which are less energy-intensive to produce as they often include magnesia, enabling the absorption of carbon dioxide during curing.
Optimising the use of less polluting materials is an important way of cutting embedded carbon in new buildings. Around half of all CO2 emissions in the industry are from cement production, both in the manufacturing process and as a by-product of the chemical reactions. Low-carbon cements are available which are less energy-intensive to produce as they often include magnesia, enabling the absorption of carbon dioxide during curing.
For more information, see Research on novel cements to reduce CO2 emissions.
Other 'sustainable' materials such as timber, straw and compressed earth have lower carbon footprints than cement, as well as absorbing CO2 while growing.
For more information see: Sustainable materials. -
Waste management - Cutting waste through the three Rs reduce, reuse and recycle is an important hierarchy for cutting CO2 emissions in construction. Waste is often produced by ordering excess materials for a project, which emphasises the need for accurate estimating and having effective strategies for reusing materials on other projects.
Cutting waste through the three Rs reduce, reuse and recycle is an important hierarchy for cutting CO2 emissions in construction. Waste is often produced by ordering excess materials for a project, which emphasises the need for accurate estimating and having effective strategies for reusing materials on other projects.
Programmes such as the Waste and Resources Action Programme (WRAP) attempt to encourage efforts towards a resource-efficient economy.
See also: Site waste management plan and Waste hierarchy for construction.
Transportation - Currently, transportation accounts for around 20% of the UKs carbon dioxide emissions. Solutions that could be adopted include switching to more efficient vehicles and plant; sourcing materials locally thereby reducing the distance they have to be transported; and trying to condense deliveries from the same suppliers wherever possible as a means of reducing the number of journeys needed to and from the site.
Currently, transportation accounts for around 20% of the UKs carbon dioxide emissions. Solutions that could be adopted include switching to more efficient vehicles and plant; sourcing materials locally thereby reducing the distance they have to be transported; and trying to condense deliveries from the same suppliers wherever possible as a means of reducing the number of journeys needed to and from the site.
Other strategies - There are several other strategies that can be undertaken to reduce CO2 on construction sites, such as:
There are several other strategies that can be undertaken to reduce CO2 on construction sites, such as:
Producing an energy plan during early planning stages to assess the energy requirements of the project;
Securing early, high-capacity electricity grid connection, thereby reducing the need for generators;
Avoid using oversized generators; - Efficient energy management in site offices, such as intelligent electrical installations (i.e. daylight sensors);
Efficient energy management in site offices, such as intelligent electrical installations (i.e. daylight sensors);
Using site accommodation with an energy performance certificate (EPC) rating of A, B or C to reduce heating and lighting costs, and
Avoid leaving plant and vehicles idling. - Energy consumption
Energy consumption - Around 80% of the emissions associated with the built environment are from buildings in use. Strategies to reduce this, include designing buildings that consume less energy, and ensuring that renewable energy is sourced. In addition, energy consumption can be directly attributed to the the lifecycle of building products and materials. For more information, see Embodied energy.
Around 80% of the emissions associated with the built environment are from buildings in use. Strategies to reduce this, include designing buildings that consume less energy, and ensuring that renewable energy is sourced. In addition, energy consumption can be directly attributed to the the lifecycle of building products and materials. For more information, see Embodied energy.
Carbon capture and storage - Carbon capture and storage (CCS) refers to a range of technologies that capture CO2 emissions and then store them permanently so that they do not enter the atmosphere and contribute to climate change. For more information, see Carbon capture and storage.
Carbon capture and storage (CCS) refers to a range of technologies that capture CO2 emissions and then store them permanently so that they do not enter the atmosphere and contribute to climate change. For more information, see Carbon capture and storage.
Construction dust - Dust.jpg
Dust.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of dust
2 Types of dust - 3 Health risks
3 Health risks - 4 Nuisance
4 Nuisance - 5 Assessing the risks
5 Assessing the risks - 6 Controlling the risks
6 Controlling the risks - 6.1 Prevention or reduction of dust
6.1 Prevention or reduction of dust - 6.2 Controlling dust levels
6.2 Controlling dust levels - 6.3 Respiratory protective equipment (RPE)
6.3 Respiratory protective equipment (RPE) - 6.4 Other controls
6.4 Other controls - 7 Reviewing the controls
7 Reviewing the controls - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - 9 External resources
9 External resources - Introduction
Introduction - Construction dust includes a number of different types of dusts that are commonly generated on construction sites. They can be dirty and cause nuisance, but can also be seriously damaging to health, sometimes with long-term implications.
Construction dust includes a number of different types of dusts that are commonly generated on construction sites. They can be dirty and cause nuisance, but can also be seriously damaging to health, sometimes with long-term implications.
Construction workers have a particularly high risk of developing health problems as a result of prolonged exposure to high levels of dust. The Health and Safety Executive (HSE) estimate that more than 500 construction workers a year are believed to die from exposure to silica dust.
There are many routine tasks on a construction site that are capable of producing high levels of dust:
Cutting paving blocks, kerbs and flags. - Chasing concrete and raking mortar.
Chasing concrete and raking mortar. - Dry sweeping site areas.
Dry sweeping site areas. - Cutting roofing tiles.
Cutting roofing tiles. - Scabbling or grinding concrete or other construction materials.
Scabbling or grinding concrete or other construction materials.
Soft strip demolition. - Cutting and sanding wood.
Cutting and sanding wood. - Sanding taped and covered plasterboard joints.
Sanding taped and covered plasterboard joints. - The Control of Substances Hazardous to Health Regulations 2002 (COSHH) regulate activities that may expose workers to construction dust. It provides a legal duty for employers to prevent or adequately control worker exposure, and requires that risks are assessed and controlled and that controls are reviewed.
The Control of Substances Hazardous to Health Regulations 2002 (COSHH) regulate activities that may expose workers to construction dust. It provides a legal duty for employers to prevent or adequately control worker exposure, and requires that risks are assessed and controlled and that controls are reviewed.
Types of dust - The three main types of dust encountered on construction sites are:
The three main types of dust encountered on construction sites are:
Silica dust: Created when working on materials that contain silica, such as concrete, mortar and sandstone.
Wood dust: Created when working on softwood, hardwood, and wood-based products such as MDF and plywood.
Lower toxicity dusts: Created when working on materials containing little-to-no silica, such as gypsum (in plasterboard), limestone, dolomite and marble.
Health risks - Dust builds up in the lungs and while the effects may not immediately be obvious, over a prolonged period of time, exposure to high levels of dust can lead to permanent damage to the lungs and airways. Some of the dust-related diseases that most affect construction workers include:
Dust builds up in the lungs and while the effects may not immediately be obvious, over a prolonged period of time, exposure to high levels of dust can lead to permanent damage to the lungs and airways. Some of the dust-related diseases that most affect construction workers include:
Lung cancer. - Silicosis.
Silicosis. - Chronic obstructive pulmonary disease (COPD).
Chronic obstructive pulmonary disease (COPD). - Asthma.
Asthma. - Nuisance
Nuisance - Construction dust is a potential cause of nuisance to neighbours.
Construction dust is a potential cause of nuisance to neighbours.
Reasonable precautions that might be taken to reduce or avoid nuisance in construction might include:
Keeping neighbours informed. - Providing a help line so that problems can be reported.
Providing a help line so that problems can be reported.
Storing fine materials under cover. - Damping fine materials and roadways.
Damping fine materials and roadways. - Minimising demolition or crushing dust.
Minimising demolition or crushing dust. - Washing down vehicles.
Washing down vehicles. - Taking care when deciding transport routes.
Taking care when deciding transport routes. - Providing hard-surfaced roadways.
Providing hard-surfaced roadways. - Proper waste management.
Proper waste management. - Using well-maintained machinery.
Using well-maintained machinery. - Careful sub-contractor management.
Careful sub-contractor management. - Assessing the risks
Assessing the risks - There are a number of factors that will contribute to risks from dust:
There are a number of factors that will contribute to risks from dust:
Risk is increased with the more energy that the work involves. High-energy tools like cut-off saws, grinders and grit blasters produce a lot of dust in a very short time.
Dust will build up depending on how enclosed with working area is.
The longer the work takes the more dust there will be.
Risks are increased by regularly doing the same work day after day.
It is important that workers are made aware of the risks from dust and how it can harm their health. They must be fully-trained and informed how to use dust control measures that have been put in place, how to maintain equipment, and how to use and look after respiratory protective equipment (RPE).
Dust2.jpg -
Controlling the risks - Prevention or reduction of dust
Prevention or reduction of dust - Methods for preventing or reducing dust levels should be assessed prior to work beginning. Measures could include:
Methods for preventing or reducing dust levels should be assessed prior to work beginning. Measures could include:
Using building materials that do not require an excessive amount of preparatory cutting to size.
Silica-free abrasives to reduce risk when blasting. - Using less-powerful tools, such as a block splitter instead of a higher energy cut-off saw.
Using less-powerful tools, such as a block splitter instead of a higher energy cut-off saw.
Adopting a different working method, such as direct fastening/screws, or hand-cutting roof tiles.
Controlling dust levels - There are two main methods for controlling the level of dust that gets into the air:
There are two main methods for controlling the level of dust that gets into the air:
Water suppression: Water helps to damp down clouds of dust. Care must be taken to use the right level of water for the whole duration of the work.
On-tool extraction: Local exhaust ventilation (LEV) systems can be fitted directly onto tools and works to remove dust as it is produced.
Respiratory protective equipment (RPE) - Preventative and control measures may not always be sufficient, making protective equipment such as powered face masks necessary. Different types of RPE are given an assigned protection factor (APF) which indicates the level of protection it provides. An APF of 20 is the general level for construction dust, which means that the wearer breathes only one-twentieth of the amount of dust in the air.
Preventative and control measures may not always be sufficient, making protective equipment such as powered face masks necessary. Different types of RPE are given an assigned protection factor (APF) which indicates the level of protection it provides. An APF of 20 is the general level for construction dust, which means that the wearer breathes only one-twentieth of the amount of dust in the air.
The RPE must be suitable and comfortable for the work, compatible with other items of protective equipment, and should be worn correctly by the worker.
For more information, see Fit testing. -
Other controls - These prevention and control techniques may need to be used in combination with other controls, such as:
These prevention and control techniques may need to be used in combination with other controls, such as:
Keeping the number of workers near the dust-producing work area to a minimum.
Using sheeting and temporary screens to enclose the work area.
Using general mechanical ventilation to remove dust-filled air from the work area.
Rotating workers working on the dust-producing activity. - Reviewing the controls
Reviewing the controls - It is important that as well as assessing the risks and putting controls in place, regular reviews are held to ensure that they are working correctly. Procedures should be put in place to ensure that dust-producing work is being done correctly and in the safest possible way.
It is important that as well as assessing the risks and putting controls in place, regular reviews are held to ensure that they are working correctly. Procedures should be put in place to ensure that dust-producing work is being done correctly and in the safest possible way.
Equipment must be maintained appropriately, with RPE filters changed regularly. A thorough examination and test of any on-tool extraction system should be carried out at least every 14 months.
Workers should be involved by consulting them on any problems and solutions that could be introduced. They should also be supervised to ensure they are using the provided controls and the correct work method.
Flat roof - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Coverings
2 Coverings - 3 Deck
3 Deck - 3.1 Concrete slab flat roofs
3.1 Concrete slab flat roofs - 3.2 Timber flat roofs
3.2 Timber flat roofs - 4 Find out more
4 Find out more - 4.1 Related articles on Designing Buildings Wiki
4.1 Related articles on Designing Buildings Wiki - 5 External references
5 External references - Introduction
Introduction - A flat roof is a roof that is completely, or almost level. However, whilst they are described as flat almost all flat roofs are actually laid to a fall to ensure that rainwater can run off to the lower side. Typically they are designed to have a minimum fall of 1:40, which given on-site inaccuracies should result in a minimum fall of at least 1:80 in the finished construction.
A flat roof is a roof that is completely, or almost level. However, whilst they are described as flat almost all flat roofs are actually laid to a fall to ensure that rainwater can run off to the lower side. Typically they are designed to have a minimum fall of 1:40, which given on-site inaccuracies should result in a minimum fall of at least 1:80 in the finished construction.
This is in contrast with a pitched roof which slopes.
The Scottish Technical Handbook - Domestic, describes flat roofs as roofs, '...the slope of which does not exceed 10 from the horizontal'.
While very common in countries with warm climates, flat roofs were only widely adopted in the UK after the Second World War. They were seen as a cheaper alternative to traditional pitched roofs. However, the longevity of some flat roofs has been poor, ranging from 6 years to 35 years depending on the quality of the covering and the structure.
Coverings - Common flat roof coverings include:
Common flat roof coverings include: -
Sheet materials such as bituminous felt. - In situ material materials such as asphalt.
In situ material materials such as asphalt. - Metal such as lead or copper.
Metal such as lead or copper. - These roof coverings are generally designed to be laid as flat, continuous sheets, and they are prone to weakness where they are bent; for example at parapets and verges, where they are penetrated by ducts, flues, and so on, and at joints or seams.
These roof coverings are generally designed to be laid as flat, continuous sheets, and they are prone to weakness where they are bent; for example at parapets and verges, where they are penetrated by ducts, flues, and so on, and at joints or seams.
Deck - Concrete slab flat roofs
Concrete slab flat roofs - A concrete slab flat roof is normally made up of a structural layer of concrete finished with a smooth screed onto which a water proof layer such as a membrane is laid. The roof should incorporate insulation and usually a vapour control layer to protect from interstitial condensation.
A concrete slab flat roof is normally made up of a structural layer of concrete finished with a smooth screed onto which a water proof layer such as a membrane is laid. The roof should incorporate insulation and usually a vapour control layer to protect from interstitial condensation.
Timber flat roofs - Timber flat roof construction usually consists of structural joists topped with a decking of plywood or a similar sheet material. Wherever possible, joists should span the shortest distance of the roof plan . The pitch is governed by the roof covering and the required rate of rainwater discharge.
Timber flat roof construction usually consists of structural joists topped with a decking of plywood or a similar sheet material. Wherever possible, joists should span the shortest distance of the roof plan . The pitch is governed by the roof covering and the required rate of rainwater discharge.
There are a number of different possible methods of creating a fall (slope):
Joists cut to falls with flat soffit: These are simple to fix but may not be very economical in terms of timber usage, unless two joists are cut from one piece.
Joists laid to falls with sloping soffit: Economic and simple but the sloping soffit may need to be hidden by a flat suspended ceiling.
Firrings (tapered strips fixed above the joists) with joist run: Simple and effective but it does not provide a means of natural cross ventilation.
Firrings against joist run: Simple, effective, and provides a means of natural cross ventilation, but uses more timber.
The loadings and span of the flat roof will determine the spacing and sizes of the joists required.
As with concrete flat roofs, a timber construction will be finished with a waterproof covering such as a membrane, or a sheet material such as lead. Insulation will be incorporated within the roof build up, together with a vapour control layer to protect from interstitial condensation.
Garages may be un-insulated, but most roofs above the habitable part of the house will need to be insulated to comply with Building Regulations.
Conservation of energy can be achieved in two ways:
Cold roof: Insulation is placed on the ceiling lining, between the joists.
Warm roof: Insulation is placed below the waterproof covering, above the roof decking.
Inverted roof: Insulation is placed above the waterproof covering.
Pitched roof - Metalroof.jpg
Metalroof.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of pitched roof
2 Types of pitched roof - 2.1 Mono pitch roof
2.1 Mono pitch roof - 2.2 Couple roof
2.2 Couple roof - 2.3 Closed couple roof
2.3 Closed couple roof - 2.4 Collar roof
2.4 Collar roof - 2.5 Purlin roof
2.5 Purlin roof - 2.6 Large section truss
2.6 Large section truss - 2.7 Trussed rafter
2.7 Trussed rafter - 3 Coverings
3 Coverings - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - Introduction
Introduction - A pitched roof is a roof that slopes downwards, typically in two parts at an angle from a central ridge, but sometimes in one part, from one edge to another. The pitch of a roof is its vertical rise divided by its horizontal span and is a measure of its steepness.
A pitched roof is a roof that slopes downwards, typically in two parts at an angle from a central ridge, but sometimes in one part, from one edge to another. The pitch of a roof is its vertical rise divided by its horizontal span and is a measure of its steepness.
A pitched roof is in contrast to a flat roof which, technically, is any roof with a slope less than 10; however, in practise they tend to be much shallower, commonly being expressed as a gradient and can be anywhere from 1:40 to 1:80. For more information, see Flat roof.
The National Calculation Methodology (NCM) modelling guide (for buildings other than dwellings in England) 2013 edition, published by the Department for Communities and Local Government (DCLG) considers that a pitched roof is a 'Roof with pitch greater than 20 deg and less than or equal to 70 deg if the pitch is greater than 70 deg, it must be considered a wall.'
The two basic construction methods of pitched roofs are:
Cut roof: A traditional method of cutting timber on-site and building up the roof using rafters, joists, purlins, ridge boards, etc.
Truss roof: Prefabricated trusses which are delivered to site and erected.
There are also a number of other framed constructions, such as portal frame roofs.
Types of pitched roof - There are several different types of pitched roof:
There are several different types of pitched roof:
Mono pitch roof - A mono pitch roof is one which slopes from one side of a building (or part of it) to another. The mono pitch roof was commonly used to form extensions in Victorian times and is still used in a similar fashion today. In domestic construction, it typically comprises a series of rafters fixed to walls at either end of the roof span which support battens to which the roof covering is fixed.
A mono pitch roof is one which slopes from one side of a building (or part of it) to another. The mono pitch roof was commonly used to form extensions in Victorian times and is still used in a similar fashion today. In domestic construction, it typically comprises a series of rafters fixed to walls at either end of the roof span which support battens to which the roof covering is fixed.
For more information, see Mono pitch roof.
Couple roof - Often referred to as the simplest form of pitched roof, the couple roof comprises two lengths of timber (rafters) leaning against one another, tied where they meet at the top.
Often referred to as the simplest form of pitched roof, the couple roof comprises two lengths of timber (rafters) leaning against one another, tied where they meet at the top.
For more information, see Couple roof. -
Closed couple roof - By adding ceiling joists, a length of timber running horizontally between the rafter feet, to the couple roof form, the structure becomes much more secure. The joist acts as a tie preventing the outward deflection of the wall and increases the potential roof-span. they can also be used to support a flat ceiling.
By adding ceiling joists, a length of timber running horizontally between the rafter feet, to the couple roof form, the structure becomes much more secure. The joist acts as a tie preventing the outward deflection of the wall and increases the potential roof-span. they can also be used to support a flat ceiling.
For more information, see Closed couple roof.
Collar roof - By raising the height of the ceiling joists higher than the bottom of the rafters, the collar roofa llows upper rooms to be constructed partly in the roof space, leading to some economies by slightly reducing the height of the external walls and therefore the amount of brickwork needed.
By raising the height of the ceiling joists higher than the bottom of the rafters, the collar roofa llows upper rooms to be constructed partly in the roof space, leading to some economies by slightly reducing the height of the external walls and therefore the amount of brickwork needed.
For more information, see Collar roof. -
Purlin roof - In order to increase potential roof spans without compromising wall stability, increasing rafter sizes or attracting extra costs, purlins can be introduced. By installing a purlin into the roof structure, rafters are given extra support and no longer needed to be as thick and heavy.
In order to increase potential roof spans without compromising wall stability, increasing rafter sizes or attracting extra costs, purlins can be introduced. By installing a purlin into the roof structure, rafters are given extra support and no longer needed to be as thick and heavy.
Rafters.jpg -
For more information, see Purlin roof. -
Large section truss - Trusses enable wider spans to be achieved than previous methods. Until the 1920's, it was common to have two trusses in a typical dwelling, however more could be used, depending on the load.
Trusses enable wider spans to be achieved than previous methods. Until the 1920's, it was common to have two trusses in a typical dwelling, however more could be used, depending on the load.
For more information, see Large section truss.
Trussed rafter - In modern house construction the most common form of trussed rafter is known as the fink or 'w' truss. This consists of a rafter incorporating tension and compression members in the shape of a W. This trussed rafter is capable of spans up to 12 m and can be designed to accommodate many different pitch angles.
In modern house construction the most common form of trussed rafter is known as the fink or 'w' truss. This consists of a rafter incorporating tension and compression members in the shape of a W. This trussed rafter is capable of spans up to 12 m and can be designed to accommodate many different pitch angles.
For more information, see Trussed rafter. -
Coverings - The most common types of covering for pitched roofs are:
The most common types of covering for pitched roofs are:
Felt and battens. - Plain tiles.
Plain tiles. - Interlocking tiles.
Interlocking tiles. - Slates.
Slates. -
Building evacuation - International Fire Safety Standards: Common Principles, Safe Buildings Save Lives, First Edition, published by the International Fire Safety Standards Coalition in 2020 defines evacuation as: The procedures and processes used to enable people to leave a Building.
International Fire Safety Standards: Common Principles, Safe Buildings Save Lives, First Edition, published by the International Fire Safety Standards Coalition in 2020 defines evacuation as: The procedures and processes used to enable people to leave a Building.
Building evacuation is the process of making sure everyone inside a building gets out safely and in a timely and controlled manner in the event of an emergency, such as fire. Buildings commonly use equipment such as fire alarms, exit signage, emergency lighting and emergency escape routes to facilitate evacuations.
In 1994, John Abrahams investigated building evacuation strategies and found that the independent variables were the buildings complexity and the mobility of the individuals. The strategy changes from fast egress to slow egress as the complexity increases and mobility decreases. At the end of this scale is the strategy of moving to a safe place inside the building where help can reach the individuals. In most buildings, these Safe Havens will be in the stairwell, and in areas with a particular risk of earthquakes, buildings may incorporate them on each floor.
A simultaneous evacuation is where building occupants react to the alarm and follow the designated means of escape to the place of safety away from the building. This may not be suitable or practicable for larger or more complex buildings due to the risks of congestion at escape routes. These buildings may be designed so that evacuation is initially limited to those nearest the hazard, before being extended if necessary to others. This type of phased evacuation strategy requires different alarm signals a warning and an evacuation signal.
Complex or large buildings, or those with occupants who may be immobile, such as hospitals and care homes, may be sub-divided into different fire compartments to allow slower evacuation times. Public buildings such as cinemas and theatres may have a staff alarm which enables pre-arranged evacuation plans to be put into action.
The Regulatory Reform (Fire Safety) Order 2005 requires that owners of premises other than private dwellings appoint a responsible person who takes reasonable steps to make sure people can safely escape if there is a fire.
A fire marshal, also known as a fire warden, is an individual who is allocated, or who volunteers, to take on fire safety responsibilities for their organisation. In the event of an emergency, they must helping evacuate people from the building to assembly points, ensure they have a list of those who are normally present in the building, as well as the signing-in book, and carry out a roll-call to ensure everyone has left the building safely.
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, defines means of escape as:
Structural means whereby [in the event of fire] a safe route or routes is or are provided for persons to travel from any point in a building to a place of safety.
The approved document defines an escape route as that part of the means of escape from any point in a building to a final exit where a final exit is The termination of an escape route from a building giving direct access to a street, passageway, walkway or open space and sited to ensure the rapid dispersal of persons from the vicinity of a building so that they are no longer in danger from fire and/or smoke.
Escape routes may involve protected corridors, lobbies or stairways which are protected from fire in adjoining accommodation by fire-resisting construction.
Exit - Exit-1773916 640.jpg
Exit-1773916 640.jpg -
The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, defines an exit as: a point of egress from a room, storey, protected zone, space, gallery, catwalk or openwork floor which forms part of, or gives access to, an escape route or place of safety.
This example of duplitecture is a copy of the main square Halstatt. It was built near Huizou, Guangdong Province.
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 History
2 History - 3 What defines duplitecture?
3 What defines duplitecture? - 4 Decrease in duplitecture popularity
4 Decrease in duplitecture popularity - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - Introduction
Introduction - Duplitecture is a term that describes duplicated architecture, replicated architecture or copycat architecture. This form of architectural mimicry is primarily found in China.
Duplitecture is a term that describes duplicated architecture, replicated architecture or copycat architecture. This form of architectural mimicry is primarily found in China.
History - Copycat buildings are not new in China. Its origins trace back to the first emperor of a unified China, Qin Shi Huang (259 BC - 210 BC), who is known for his terracotta army.
Copycat buildings are not new in China. Its origins trace back to the first emperor of a unified China, Qin Shi Huang (259 BC - 210 BC), who is known for his terracotta army.
As a display of power and superiority, replica landmarks were made for imperial rulers to show off noteworthy places they defeated. These leaders would also replicate foreign gardens by importing plants and wildlife that would have been found in the conquered area.
In its modern iteration, duplitecture gained popularity during Shanghai's "One City, Nine Towns" plan. This government initiative, which was meant to ease overcrowding in Shanghais city centre, resulted in the creation of 10 duplitecture satellite cities based on the architectural styles of different European countries.
What defines duplitecture? - Duplitecture should not be confused with scaled down replicas found in places such as Las Vegas or Disney Worlds Epcot theme park. Instead, its structures are commonly produced on (or close to) the same scale as the originals, although there may be some changes due to material availability or other matters. There may also be aesthetic changes, such as colour.
Duplitecture should not be confused with scaled down replicas found in places such as Las Vegas or Disney Worlds Epcot theme park. Instead, its structures are commonly produced on (or close to) the same scale as the originals, although there may be some changes due to material availability or other matters. There may also be aesthetic changes, such as colour.
These buildings are primarily designed by Chinese architects. They are often meant to be entirely functional spaces. They may incorporate ideological adaptations, such as those associated with Feng shui, to enhance their habitability.
Some duplitecture projects replicate easily identifiable buildings. One example is the US White House - which is one of the most popular duplitecture structures in China.
Others reproduce large portions of identifiable European or American cities. These examples may be older cities, such as Venice (complete with canals) or Paris (with 12 square miles of housing along with a copy of the Eiffel Tower). Both of these duplitecture communities are located in the suburbs of Hangzhou.
Other duplitecture examples may be a patchwork collection of familiar architectural styles and iconic elements associated with specific countries. One instance is Thames Town in the outskirts of Shanghai - with its mock Tudor buildings, red telephone boxes, English pub, statues of Churchill, Shakespeare, James Bond and so on.
Instances of duplitecture can be found in the suburbs of several Chinese cities. While some critics take issue with their lack of authenticity, others acknowledge the craftsmanship of the reproductions.
Some of the communities include business-related incentives that support the authenticity of the reproduction. For example, a French bakery might be found in a Paris duplitecture community.
Decrease in duplitecture popularity - Many of the Chinese duplitecture projects built in the 2000s have lost their residential appeal. People have moved away from the novelty communities, leaving the cities largely abandoned. However, they are still relatively popular as tourist attractions and as backdrops to photoshoots - particularly for weddings.
Many of the Chinese duplitecture projects built in the 2000s have lost their residential appeal. People have moved away from the novelty communities, leaving the cities largely abandoned. However, they are still relatively popular as tourist attractions and as backdrops to photoshoots - particularly for weddings.
Emergency lighting - Emergency-light.png
Emergency-light.png -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of fitting
2 Types of fitting - 2.1 Maintained fitting
2.1 Maintained fitting - 2.2 Non-maintained fitting
2.2 Non-maintained fitting - 2.3 Sustained fitting
2.3 Sustained fitting - 3 Other categorisations
3 Other categorisations - 4 Technical requirements
4 Technical requirements - 4.1 Open areas
4.1 Open areas - 4.2 Escape route
4.2 Escape route - 4.3 Stairwells
4.3 Stairwells - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - Introduction
Introduction - Emergency lighting is installed in buildings in case of a mains power failure and provides sufficient illumination to allow occupants of the building to evacuate safely. Types of emergency lighting include; emergency exit signs, recessed fluorescent lights, powerful halogen emergency spotlights for larger spaces, emergency ceiling lights and downlights, and so on.
Emergency lighting is installed in buildings in case of a mains power failure and provides sufficient illumination to allow occupants of the building to evacuate safely. Types of emergency lighting include; emergency exit signs, recessed fluorescent lights, powerful halogen emergency spotlights for larger spaces, emergency ceiling lights and downlights, and so on.
The Regulatory Reform (Fire Safety) Order 2005 requires that 'emergency routes and exits requiring illumination must be provided with emergency lighting of adequate intensity in the case of failure of their normal lighting.'
The requirement does not apply to domestic premises.
Approved document B defines emergency lighting as 'lighting for use when the power supply to the normal lighting fails'. It defines escape lighting as 'The part of the emergency lighting that is provided to ensure that the escape route is illuminated at all material times.'
Approved document L defines emergency escape lighting as '......that part of emergency lighting that provides illumination for the safety of people leaving an area or attempting to terminate a dangerous process before leaving.'
In addition to the requirement to illuminate emergency routes and exits, open area lighting may be provided to allow occupants to reach an escape route, and where occupants are involved in activities that may present some danger if they are not completed, there may be high-risk task area lighting. There may also be standby lighting to allow occupants to continue with their normal activities in the event of a power failure.
Emergency lights are powered by back-up batteries. The lights detect when mains power has failed and immediately switch to using the back-up battery. The battery should be capable of powering the light, for a defined period, but as a means of conserving power, the light output may be reduced, sometimes to just 10% of the normal output.
The Fire Precautions (Workplace) Regulations 1997 and BS 5266 part 1 require that building owners test emergency lighting regularly and maintain them in proper working order. Light fittings have a green LED indicator which shows they are charged and functional.
Types of fitting - There are three basic types of emergency light fitting:
There are three basic types of emergency light fitting:
Maintained fitting - This type of fitting is designed to operate as a normal light fitting, to be lit continuously and to be controlled along with the other lights in the area. However, if power fails the maintained emergency fitting will continue to operate at a lower light output level. This type of lighting is commonly used in public buildings such as theatres, cinemas and shopping centres.
This type of fitting is designed to operate as a normal light fitting, to be lit continuously and to be controlled along with the other lights in the area. However, if power fails the maintained emergency fitting will continue to operate at a lower light output level. This type of lighting is commonly used in public buildings such as theatres, cinemas and shopping centres.
Non-maintained fitting - This type of fitting is normally switched off, but is designed to switch on automatically in the event of a mains power failure. The batteries are continuously charged. These are typically fittings such as emergency exit signs which are not required as part of general lighting. They are commonly used in workplaces such as offices and factories, where there may be more occupant familiarity with the building and the escape routes.
This type of fitting is normally switched off, but is designed to switch on automatically in the event of a mains power failure. The batteries are continuously charged. These are typically fittings such as emergency exit signs which are not required as part of general lighting. They are commonly used in workplaces such as offices and factories, where there may be more occupant familiarity with the building and the escape routes.
Sustained fitting - Includes two lamps, one operating on a mains supply, and the other operating in the event of mains power failure from a battery source.
Includes two lamps, one operating on a mains supply, and the other operating in the event of mains power failure from a battery source.
Other categorisations - Fittings may be self-contained, with their own batteries, or may be powered from a central battery source.
Fittings may be self-contained, with their own batteries, or may be powered from a central battery source.
They can have varying durations for which they are able to remain illuminated following a mains power failure, such as 1 hour, 2 hour, 3 hour and so on.
They may provide different levels of illumination. See below.
Technical requirements - The specification for emergency lighting will depend on the area it is intended to illuminate.
The specification for emergency lighting will depend on the area it is intended to illuminate.
Open areas - A non-obstructed escape route must be lit during an emergency to a minimum of 1 lux. Emergency lighting isnt required if the open area is less than 60 sq. m and isnt part of a designated escape route. The exit doors for the emergency escape route must be fitted with signs or an emergency bulkhead light.
A non-obstructed escape route must be lit during an emergency to a minimum of 1 lux. Emergency lighting isnt required if the open area is less than 60 sq. m and isnt part of a designated escape route. The exit doors for the emergency escape route must be fitted with signs or an emergency bulkhead light.
Escape route - A designated corridor or other escape route must be unobstructed and, during an emergency, be lit to a minimum of 1 lux.
A designated corridor or other escape route must be unobstructed and, during an emergency, be lit to a minimum of 1 lux.
Stairwells - As stairwells provide increased levels of hazard than unobstructed spaces, they must be lit during an emergency to a minimum of 2 lux.
As stairwells provide increased levels of hazard than unobstructed spaces, they must be lit during an emergency to a minimum of 2 lux.
Concrete joint - Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014, suggests that construction joints (in concrete, sometimes referred to as daywork joints) refer to: A joint in concrete construction formed when placement of the concrete is interrupted for some reason. It may be the end of the days work, or it may be that some other work needs to be completed before resuming the placement. Results in a surface between freshly placed and (partly) cured concrete.
Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014, suggests that construction joints (in concrete, sometimes referred to as daywork joints) refer to: A joint in concrete construction formed when placement of the concrete is interrupted for some reason. It may be the end of the days work, or it may be that some other work needs to be completed before resuming the placement. Results in a surface between freshly placed and (partly) cured concrete.
Crack control joints are: A partially-formed contraction joint, which aims to ensure that when the concrete does crack, it cracks in a predictable manner at a precise location.
Contraction or shrinkage joints (in concrete): Allows only for contraction or shrinkage of a slab or wall, as can be anticipated during the curing process.
Expansion joints (in concrete): Allow expansion and contraction of a concrete slab or wall without generating potentially damaging forces within the slab itself or the surrounding structures. Expansion joints are usually a complete gap between adjacent bays, ie there is a definite break in the concrete and reinforcing steel that may be present. Where adjacent bays are tied together by means of dowel bars, these dowels are sleeved in one of the bays to allow expansion to take place without generating stresses within the slab.
A kicker joint is a: Small upstand cast as part of a concrete base to allow the securing of wall shutters.'
External environment - Netherlands landscape 97830 640.jpg
Netherlands landscape 97830 640.jpg -
In its broadest sense, the term environment refers to all of the things around us. These things can affect our comfort, wellbeing, performance, behaviour, growth and development. In turn, our behaviour can impact on the environment around us.
The environment comprises the built environment and the natural environment. For more information see: Environment.
The phrase external environment typically refers to the environment that exists outside buildings or other enclosures. This is as opposed to the internal environment, which comprises the environment inside buildings and other enclosures.
The external environment can include aspects of the built environment and of the natural environment. The common concept of the natural environment encompasses two different components:
Ecological units that operate as natural systems (such as soil, vegetation and so on).
Universal natural resources (such as air and water).
The built environment is increasingly developed in a way that considers both its resilience to and its impact on the natural environment.
The external environment might be formed by its:
Size, form, layout, texture, landscape, seascape and so on.
Acoustic environment. - Visual environment.
Visual environment. - Thermal environment.
Thermal environment. - Air quality.
Air quality. - Ecology.
Ecology. - The term external works describes any construction works carried out to the external environment. RICSs New Rules of Measurement Part 3 (NRM3) categorises external works as:
The term external works describes any construction works carried out to the external environment. RICSs New Rules of Measurement Part 3 (NRM3) categorises external works as:
Site preparation works. - Roads, paths, pavings and surfacings.
Roads, paths, pavings and surfacings. - Soft landscaping, planting and irrigation systems.
Soft landscaping, planting and irrigation systems. - Fencing, railings and walls.
Fencing, railings and walls. - External fixtures.
External fixtures. - External drainage.
External drainage. - External services.
External services. - Minor building works and ancillary buildings.
Minor building works and ancillary buildings. - For more information see: External works.
For more information see: External works. -
NB The phrase external environment can also be used to refer to the factors outside an organisation that can influence its activities and decision making. This might include; economic conditions, events, policies and so on. Typically, this is considered to comprise a micro environment (such as suppliers and customers) and a macro environment (cultural, political and economic conditions and so on).
Indoor environmental quality - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Factors influencing indoor environmental quality
2 Factors influencing indoor environmental quality - 3 Optimal indoor environmental quality design
3 Optimal indoor environmental quality design - 4 Building management to improve indoor environmental quality
4 Building management to improve indoor environmental quality - 5 Related articles on Designing Buildings Wiki.
5 Related articles on Designing Buildings Wiki. - Introduction
Introduction - With people generally spending more time indoors, and buildings being more tightly constructed and isolated from the external environment, a greater importance is being placed on the indoor environment.
With people generally spending more time indoors, and buildings being more tightly constructed and isolated from the external environment, a greater importance is being placed on the indoor environment.
Indoor environmental quality (IEQ) is a general indicator of the quality of conditions inside a building. It can also include functional aspects of space, for example whether the layout provides access to equipment when needed and whether the building has sufficient space for its occupants.
A better indoor environmental quality can enhance the wellbeing of building occupants and help decrease the occurrence of sick building syndrome and building related illness. It can also lead to a decrease in worker complaints and absenteeism which in turn can improve productivity.
Factors influencing indoor environmental quality - The indoor building environment is complex and there are a variety of factors that can influence its environmental quality.
The indoor building environment is complex and there are a variety of factors that can influence its environmental quality.
Airborne contaminants (gases and particles) from; office equipment, cleaning products, construction activities, furnishings and carpets, water-damaged building materials, microbial growth (fungal, bacterial and mould), outdoor pollutants, and so on.
Indoor air quality. - Ventilation.
Ventilation. - Humidity.
Humidity. - Thermal comfort.
Thermal comfort. - Daylight, lighting and views.
Daylight, lighting and views. - Electromagnetic frequency levels.
Electromagnetic frequency levels. - Acoustic conditions.
Acoustic conditions. - Optimal indoor environmental quality design
Optimal indoor environmental quality design - In order to optimise indoor environmental quality, the design and development process should:
In order to optimise indoor environmental quality, the design and development process should:
Ensure good quality design, construction, commissioning, operating and maintenance practices.
Consider aesthetic designs including the importance of views and the integration of natural elements.
Provide thermal comfort controls for occupants where possible.
Supply adequate levels and quality of ventilation. - Prevent airborne bacteria, mould and other fungi through a design that manages moisture sources inside and outside the building.
Prevent airborne bacteria, mould and other fungi through a design that manages moisture sources inside and outside the building.
Use building products that do not emit pollutants.
Use sound absorbing/insulating materials to help create optimal acoustic levels.
Building management to improve indoor environmental quality - There are a number of ways that the indoor environmental quality of existing buildings can be improved, including:
There are a number of ways that the indoor environmental quality of existing buildings can be improved, including:
Using fragrance-free and low VOC (volatile organic compounds) cleaning products.
Undertaking audits of cleaning products and devising a cleaning plan to replace products with safer alternatives.
Vacuuming regularly and using vacuums with HEPA (High-efficiency particulate arrestance) filters.
Ensuring that HVAC equipment is well maintained and working optimally.
Creating a door and window opening protocol to maintain sufficient air flow.
Avoiding dust blowing equipment such as leaf blowers and diesel-powered engine equipment.
When using pesticides, fertilisers and lime applications, ensuring there is little or no wind.
Maintaining buildings and furnishings to a high standard reducing the need for renovation and remodelling.
Ensuring filters in HVAC systems are properly maintained.
Optimising lighting. -
Wellbeing and buildings - In 2012, Dodge et al proposed that wellbeing could be defined as when individuals have the psychological, social and physical resources they need to meet a particular psychological, social and/or physical challenge.
In 2012, Dodge et al proposed that wellbeing could be defined as when individuals have the psychological, social and physical resources they need to meet a particular psychological, social and/or physical challenge.
The 2013 Measuring National Well-being programme suggested that the factors most strongly associated with personal well-being are:
Health. - Employment status.
Employment status. - Relationship status.
Relationship status. - Of these three factors, health had the strongest relationship with wellbeing.
Of these three factors, health had the strongest relationship with wellbeing.
The Measuring National Well-being national debate identified a range of other less significant factors associated with personal well-being, including:
Economic security. - Job satisfaction.
Job satisfaction. - Work-life balance.
Work-life balance. - Education and training.
Education and training. - Local and natural environment.
Local and natural environment. - Articles about wellbeing on Designing Buildings Wiki include:
Articles about wellbeing on Designing Buildings Wiki include:
Daylight benefits in healthcare buildings. - Integrated modelling, simulation and visualisation (MSV) for sustainable built healing environments (BHEs).
Integrated modelling, simulation and visualisation (MSV) for sustainable built healing environments (BHEs).
A measure of net well-being that incorporates the effect of housing environmental impacts.
Well-being and regeneration: Reflections from Carpenters Estate.
Anatomy of low carbon retrofits: evidence from owner-occupied superhomes.
The impact of the design of the Psychiatric inpatient facility on perceptions of Carer wellbeing.
Creating strong communities measuring social sustainability in new housing development.
The design of extra care housing for older people and its impact on wellbeing: The East Sussex perspective.
The daylight factor. - Ubiquitous sensors to assess peoples energy consumption and wellbeing in domestic environments.
Ubiquitous sensors to assess peoples energy consumption and wellbeing in domestic environments.
Airtightness of energy efficient buildings. - Adapting 1965-1980 semi-detached dwellings in the UK to reduce summer overheating and the effect of the 2010 Building Regulations.
Adapting 1965-1980 semi-detached dwellings in the UK to reduce summer overheating and the effect of the 2010 Building Regulations.
Transitioning to eco-cities: Reducing carbon emissions while improving urban welfare.
A case study of adopting BIT-Kit: A method uncovering the impact buildings have on people.
The real cost of poor housing. - Health and wellbeing impacts of natural and artificial lighting.
Health and wellbeing impacts of natural and artificial lighting.
Health and wellbeing at Kings Cross. - Wellbeing and creativity in workplace design - case studies.
Wellbeing and creativity in workplace design - case studies.
Most western developed countries now measure wellbeing as part of their national statistics. The UK reported in the 2013-2015 report "Those who identify as gay or lesbian, or bisexual report lower well-being than the UK average for all personal well-being measures. This difference is largest for feelings of anxiety."
Natural environment - The term 'natural environment' refers to the non-human-made surroundings and conditions in which all living and non-living things exist on Earth. The common concept of the natural environment encompasses two different components:
The term 'natural environment' refers to the non-human-made surroundings and conditions in which all living and non-living things exist on Earth. The common concept of the natural environment encompasses two different components:
Ecological units that operate as natural systems (such as soil, vegetation and so on).
Universal natural resources (such as air and water).
The natural environment is in contrast with the 'built environment' which refers to areas that have been fundamentally transformed and influenced by human activity, such as cities, towns, infrastructure, and so on.
Environmental modelling involves the application of multidisciplinary knowledge to explain, explore and predict the Earths response to environmental change, both natural and human-induced.
Construction plays a central role in transforming the natural environment into the built environment, and there are many considerations and restrictions that can apply before a project is given permission to proceed in terms of how it may influence the environment.
For example, an environmental impact assessment (EIA) may be required to ensure that the environmental effects of a proposed development are properly considered. An EIA provides the local planning authority with better information to make a more informed decision about whether permission should be granted and to allow imposition of more appropriate conditionsand obligations to mitigate possible negative impacts.
The green belt is intended to constrain the built environment and prevent it from spreading over the natural environment.
Ecological network - The 2010 report to Defra, Making Space for Nature: A review of Englands wildlife sites and ecological network, suggested that an ecological network comprises a suite of high quality sites which collectively contain the diversity and area of habitat that are needed to support species and which have ecological connections between them
The 2010 report to Defra, Making Space for Nature: A review of Englands wildlife sites and ecological network, suggested that an ecological network comprises a suite of high quality sites which collectively contain the diversity and area of habitat that are needed to support species and which have ecological connections between them
The government believes it is important to create an ecological network at national and local levels across England, but that this will require a fundamental shift in approaches to conservation and land management.
The 2011 Natural Environment White Paper The Natural Choice: securing the value of nature proposed that, The elements of life biodiversity, healthy soils, clean air and water, and diverse landscapes need to be managed in ways which recognise the vital connections between them. Connections can be made over land; through water or by air; or through continuous green corridors or stepping stones, to create a dynamic and resilient landscape
Building acoustics - Royal-Albert-Hall2.jpg
Royal-Albert-Hall2.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Characteristics of sound
2 Characteristics of sound - 3 Reverberation time
3 Reverberation time - 4 Sound absorption
4 Sound absorption - 5 Sound insulation
5 Sound insulation - 6 Noise nuisance
6 Noise nuisance - 7 Room acoustics
7 Room acoustics - 8 Related articles on Designing Buildings Wiki
8 Related articles on Designing Buildings Wiki - Introduction
Introduction - Building acoustics is the science of controlling noise in buildings. This includes the minimisation of noise transmission from one space to another and the control of the characteristics of sound within spaces themselves.
Building acoustics is the science of controlling noise in buildings. This includes the minimisation of noise transmission from one space to another and the control of the characteristics of sound within spaces themselves.
Building acoustics are an important consideration in the design, operation and construction of most buildings, and can have a significant impact on health and wellbeing, communication and productivity. They can be particularly significant in spaces such as concert halls, recording studios, lecture theatres, and so on, where the quality of sound and its intelligibility are very important.
Building acoustics can be influenced by: -
The geometry and volume of a space. - The sound absorption, transmission and reflection characteristics of surfaces enclosing the space and within the space.
The sound absorption, transmission and reflection characteristics of surfaces enclosing the space and within the space.
The sound absorption, transmission and reflection characteristics of materials separating spaces.
The generation of sound inside or outside the space.
Airborne sound transmission. - Impact noise.
Impact noise. - Characteristics of sound
Characteristics of sound - Sound intensity is measured in Decibels (dB). This is a logarithmic scale in which an increase of 10 dB gives an apparent doubling of loudness.
Sound intensity is measured in Decibels (dB). This is a logarithmic scale in which an increase of 10 dB gives an apparent doubling of loudness.
Sound pitch is measured in Hertz (Hz), the standard unit for the measurement for frequency. The audible range of sound for humans is typically from 20 Hz to 20,000 Hz, although, through ageing and exposure to loud sounds the upper limit will generally decrease.
As well as intensity and frequency, sound also transmits information. For example, music or speech, transmit information which people may perceive differently from other sounds.
Reverberation time - The reverberation time of a space changes the way the space sounds and can affect the intelligibility acoustic information. A high reverberation time can make a room sound muffled, loud and noisy. Rooms designed for speech typically have a low reverberation time, whereas a higher reverberation time can add depth, richness and warmth to music.
The reverberation time of a space changes the way the space sounds and can affect the intelligibility acoustic information. A high reverberation time can make a room sound muffled, loud and noisy. Rooms designed for speech typically have a low reverberation time, whereas a higher reverberation time can add depth, richness and warmth to music.
The reverberation time of a room is defined as the time it takes for sound to decay by 60 dB after an abrupt termination. It is linked to the total quantity of soft treatments and the volume of the room.
See Reverberation time for more information. -
Sound absorption - Sound absorption is the loss of sound energy when sound waves come into contact with an absorbent material such as ceilings, walls, floors and other objects, as a result of which, the sound is not reflected back into the space. Acoustic absorption can be used to reduce reverberation times.
Sound absorption is the loss of sound energy when sound waves come into contact with an absorbent material such as ceilings, walls, floors and other objects, as a result of which, the sound is not reflected back into the space. Acoustic absorption can be used to reduce reverberation times.
Absorbent materials are sometimes categorised from A to E, where A is highly absorbent and E is almost fully reflective.
Sound absorbers can be divided into three main categories:
Porous absorbents, such as fibrous materials or open-celled foam.
Resonance absorbents, which consist of a mechanical or acoustic oscillation system, such as membrane absorbers.
Single absorbers such as tables, chairs or other objects.
See sound absorption for more information -
Sound insulation - Sound transmission paths can be interrupted by sound insulation and by blocking air paths. The sound insulation of a single leaf of a material is governed by its mass, stiffening and damping.
Sound transmission paths can be interrupted by sound insulation and by blocking air paths. The sound insulation of a single leaf of a material is governed by its mass, stiffening and damping.
The sound insulation across a good conventional, lightweight, office to office construction is typically in the order of 45 dB Dw. This means that if the sound level in the source room is around 65 dB (a typical level for speech), the sound level in the adjacent room, the receiver room, will be approximately 20 dB (barely audible).
If sound levels are increased in the source room however, to 75 dB (raised voice), sound levels within the adjacent room will also increase to around 30 dB (audible). Sound insulation therefore describes the level of sound lost across a partition and not the level of sound within an adjacent room.
Dw represents the sound insulation between rooms on-site. Rw represents the lab tested sound insulation of an element making up a partition wall/floor type. Standards achieved in labs may not be possible on site because of the quality of workmanship and due to sound flanking acoustic elements, that is, travelling around them through an easier path, rather than only directly through them as under lab conditions.
The building regulations part E sets minimum standards for design and construction in relation to the resistance to the passage of sound.
See Sound insulation for more information. -
Noise nuisance - Building acoustics can help to mitigate the effects of noise disturbance which can have negative effects on health, wellbeing and general quality of life.
Building acoustics can help to mitigate the effects of noise disturbance which can have negative effects on health, wellbeing and general quality of life.
The Noise Policy Statement for England (NPSE) defines noise pollution as:
Environmental noise which includes noise from transportation sources.
Neighbour noise which includes noise from inside and outside buildings.
Neighbourhood noise which includes noise arising from industrial and entertainment premises, trade and businesses, construction sites and noise in the street.
This can be an important consideration for the location, design and construction of new developments.
See Noise nuisance for more information. -
Room acoustics - BREEAM UK New Construction, Non-domestic Buildings (United Kingdom), Technical Manual, SD5078: BREEAM UK New Construction 2018 3.0, published by BRE Global Limited, defines room acoustics as: '...how sound behaves in an enclosed space in terms of the reverberation time (or degree of echo), overall noise levels and speech intelligibility. Room acoustics are influenced by room geometry and distribution of acoustic absorption either through the general room finishes or through the introduction of sound absorbing
BREEAM UK New Construction, Non-domestic Buildings (United Kingdom), Technical Manual, SD5078: BREEAM UK New Construction 2018 3.0, published by BRE Global Limited, defines room acoustics as: '...how sound behaves in an enclosed space in terms of the reverberation time (or degree of echo), overall noise levels and speech intelligibility. Room acoustics are influenced by room geometry and distribution of acoustic absorption either through the general room finishes or through the introduction of sound absorbing
products.' -
Commissioning building systems - HVAC.jpg
HVAC.jpg -
Commissioning refers to the process of bringing an item into operation and ensuring that it is in good working order. On building projects, this refers primarily to building services.
Approved Document L1A Conservation of fuel and power in new dwellings (2010), defines commissioning as:
the advancement of a fixed building service after all or part of the system has been installed, replaced or altered. The system is taken from a state of static completion to working order. Testing and adjusting, as necessary, ensure that the whole system uses no more fuel and power than is reasonable in the circumstances, without compromising the need to comply with health and safety requirements.
'For each system, commissioning includes the following: setting-to-work; regulation (that is, testing and adjusting repetitively) to achieve the specified performance; calibration, setting up and testing of the associated automatic control systems; and recording of the system settings and the performance test results that have been accepted as satisfactory.
Building services requiring commissioning may include: -
Heating, cooling and ventilation systems. - Generators.
Generators. - Switchboards.
Switchboards. - Water supply and sanitation.
Water supply and sanitation. - Pumps.
Pumps. - Motors.
Motors. - Fire detection and protection systems.
Fire detection and protection systems. - Information and communications technology (ICT) systems.
Information and communications technology (ICT) systems.
Security systems. - Facilities management systems.
Facilities management systems. - Process plant.
Process plant. - Lifting equipment and escalators.
Lifting equipment and escalators. - Acoustic and vibration appraisals.
Acoustic and vibration appraisals. - The contract documents should set out:
The contract documents should set out: -
Who will be responsible for commissioning different building services.
What methods, standards and codes of practice are to be used.
What should happen to test results. - Whether commissioning is to be witnessed and if so, whom.
Whether commissioning is to be witnessed and if so, whom.
The documentation that is required. - Commissioning can benefit from the preparation of a commissioning plan, which according to BSRIA Guide BG 8/2009 Model Commissioning Plan should:
Commissioning can benefit from the preparation of a commissioning plan, which according to BSRIA Guide BG 8/2009 Model Commissioning Plan should:
Provide general information about the project. - Identify the commissioning team members for each stage of the commissioning process.
Identify the commissioning team members for each stage of the commissioning process.
Define roles and responsibilities for each commissioning team member.
Identify the systems to be commissioned. - Create a schedule of commissioning activities for each stage of the process.
Create a schedule of commissioning activities for each stage of the process.
Establish documentation requirements associated with the commissioning process.
A commissioning manager may be appointed to give advice during design, construction planning and installation and then to manage commissioning, testing and handover.
Commissioning activities may include: -
Ensuring client access and providing client training and demonstrations.
Completing operating and maintenance manuals, record drawings, software and test certification.
Obtaining statutory approvals and insurance approvals. - Manufacturers work testing.
Manufacturers work testing. - Component testing.
Component testing. - Pre-commissioning tests.
Pre-commissioning tests. - Set to work: this is the process of switching on (i.e. setting to work) items such as fans and motors to ensure that they are operating as specified (for example checking that fans are turning the right way).
Set to work: this is the process of switching on (i.e. setting to work) items such as fans and motors to ensure that they are operating as specified (for example checking that fans are turning the right way).
Balancing: this follows setting to work and involves looking at whole systems (rather than individual components) to ensure that they are properly balanced (i.e. water is coming out of all the taps at the correct pressure, air is coming out of the correct diffusers, etc).
Commissioning checks and performance testing. - Post commissioning checks and fine tuning during occupancy.
Post commissioning checks and fine tuning during occupancy.
NB: The building regulations require that a commissioning notice is given to the relevant building control body (BCB) confirming that commissioning has been carried out according to a procedure approved by the Secretary of State. See Commissioning notice for more information.
Setting - Conservation Principles, Policies and Guidance, For the sustainable management of the historic environment, published by Historic England in 2008, defines setting as: The surroundings in which a place is experienced, its local context, embracing present and past relationships to the adjacent landscape.
Conservation Principles, Policies and Guidance, For the sustainable management of the historic environment, published by Historic England in 2008, defines setting as: The surroundings in which a place is experienced, its local context, embracing present and past relationships to the adjacent landscape.
Context - Dancing house.jpg
Dancing house.jpg -
In its widest sense, the term 'context' refers to the circumstances or interrelated conditions that are relevant to something that exists or occurs.
In terms of the built environment, 'context' can refer to the conditions which surround a particular site or project, and to which it should relate and connect to in some way. The buildings and structures that make up the built environment do not exist in isolation but are conceived and designed in order to respond to, support and enhance their surroundings.
With the notion of context come connotations of the existing fabric, the locality, tradition and the vernacular. By embedding the intentions of a design within the essence of its surroundings, a connection linking new and old can be made, creating or maintaining a metaphysical 'place'.
The context of a building or site might include:
The topography of the area. - The sites history and previous uses.
The sites history and previous uses. - Local culture.
Local culture. - Architectural style.
Architectural style. - Local materials and construction techniques.
Local materials and construction techniques. - Weather and microclimate.
Weather and microclimate. - Political conditions.
Political conditions. - National and local policy.
National and local policy. - The state of the economy.
The state of the economy. - These factors can be analysed, adapted and adopted to make a proposed development 'fit' into its context. This can give meaning to different aspects of a project through reference to its wider surroundings.
These factors can be analysed, adapted and adopted to make a proposed development 'fit' into its context. This can give meaning to different aspects of a project through reference to its wider surroundings.
Context is one the aspects of design that might be considered when a planning application is made. Planners may reject a planning application if they do not feel a proposed development fits within the local context.
Contextualism, or contextual architecture, is a principle of design in which a structure is designed in response to its specific urban and natural environment.
Urban Design Guidelines for Victoria, published by The State of Victoria Department of Environment, Land, Water and Planning in 2017, suggests that urban context refers to: the broader setting of an identified area. The context may include the physical surroundings of topography, movement patterns and infrastructure, built form and uses, the governance structures, and the cultural, social and economic environment. The urban context can include the community vision for the area, and preferred future character, form and function.
It suggests that: 'Similar to a site analysis, context analysis provides a detailed description and examination of aspects of the wider area around a site, to determine how these aspects will effect and contribute to the design of a proposed building development or public space design. An urban context analysis informs the building development or public space design response.'
Place - United-kingdom-89977 640.jpg
United-kingdom-89977 640.jpg -
In terms of geography and the built environment, the term place is used to refer to a point or area on the Earths surface. It is commonly used in terms of human and social interactions and indicates somewhere with a boundary that can be ambiguous, as opposed to the term location which tends to imply more geometrical certainty, or space which is more abstract and tends to be used to refer to a location without human value or meaning having been attached to it.
In contrast to a space, a place can be described as a location created by human experiences, one that has a meaning due to its phenomenology.
The term genius loci originates from Roman mythology and refers to the protective spirit of a place. In antiquity, the genius loci was often depicted in religious iconography as a figure holding bowls or a snake. In contemporary usage, it can refer to a places distinctive atmosphere. For more information, see Genius loci.
A sense of place is the meaning or attachment that is held to particular places, such as a strong identity, which is a social phenomenon studied by cultural geographers, sociologists, urban planners, and so on. Place identity (also referred to as urban/local character) comprises ideas and theories about place and identity within the built environment, in terms of the significance of places for people and how they can impact or influence peoples conceptualisations of self.
Related to this is the conceptual field of psychogeography - an exploration of urban environments that examines their effect on the emotions and behaviour of people. It explores how different places impact upon people psychologically. For more information, see Psychogeography.
Within psychogeography, the French anthropologist Marc Auge coined the term non-place to describe a transient space which is largely insignificant and where humans remain anonymous and emotionally detached, such as motorways, hotel rooms, airport departure lounges, shopping centres, and so on.
In contrast, places that are deemed to be of high value can be protected and preserved by designations such as:
World Heritage Site. - Area of Outstanding Natural Beauty.
Area of Outstanding Natural Beauty. - National Historic Landmark.
National Historic Landmark. - Listed building.
Listed building. - Sites of Special Scientific Interest.
Sites of Special Scientific Interest. - Scheduled monuments.
Scheduled monuments. - Placemaking is a term used to describe the process by which an area in the public realm is given a unique and attractive character. Placemaking emerged in the 1960s when commentators, theorists and writers began to call for a greater consideration of the individuals experience of the built environment.
Placemaking is a term used to describe the process by which an area in the public realm is given a unique and attractive character. Placemaking emerged in the 1960s when commentators, theorists and writers began to call for a greater consideration of the individuals experience of the built environment.
Placemaking is the task of making an area feel attractive to inhabitants, visitors and the wider public and currently tends to be used to describe a stream of work which runs in parallel with the technical and practical work of designing the built environment.
For more information, see Placemaking. -
NB Conservation Principles, Policies and Guidance, For the sustainable management of the historic environment, Published by Historic England in 2008, suggests that: 'The term place goes beyond physical form, to involve all the characteristics that can contribute to a sense of place. It embraces the idea that places, of any size from a bollard to a building, an historic area, a town, or a region, need to be understood and managed at different levels for different purposes; and that a particular geographical location can form part of several overlapping places defined by different characteristics.'
It suggests that the significance of a place is: The sum of the cultural and natural heritage values of a place, often set out in a statement of significance.
Visual impact of buildings - Petronas-towers.jpg
Petronas-towers.jpg - The Petronas Towers in Kuala Lumpur, Malaysia.
The Petronas Towers in Kuala Lumpur, Malaysia.
Visual impact is the capacity of an object or arrangement to affect a viewer (not always positively). The opposite is making no visual impact, ie something which does not trigger any feelings in the minds of viewers.
The term visual impact is usually used in association with architecture and design, interiors, urban design and also objects. But it is unusual to refer to a person as having visual impact.
In construction, a building may have visual impact, be dynamic and generally be impressive aesthetically. A house or housing development may also have visual impact, in which case it may also be said to have 'kerb appeal', ie attracts potential buyers the moment they see it from the kerbside.
Resources in the construction industry - A resource is a source or supply of assets that can be drawn on by a person or organisation and from which a benefit is derived.
A resource is a source or supply of assets that can be drawn on by a person or organisation and from which a benefit is derived.
In the construction industry resources might include: -
Human resources. - Suppliers, contractors and consultants.
Suppliers, contractors and consultants. - Natural resources.
Natural resources. - Materials.
Materials. - Products.
Products. - Construction plant.
Construction plant. - Tools.
Tools. - Equipment.
Equipment. - Space.
Space. - Facilities.
Facilities. - Finance.
Finance. - Information.
Information. -
Natural resource - Forest.jpg
Forest.jpg - Natural resources are those sources and materials provided by nature that can either be enjoyed by, or used for, the benefit of people, but which exist independent of people. Some may be destroyed or depleted by poeple's injudicious actions.
Natural resources are those sources and materials provided by nature that can either be enjoyed by, or used for, the benefit of people, but which exist independent of people. Some may be destroyed or depleted by poeple's injudicious actions.
Types of natural resource - Earth forces (wind, magnetic, kinetic, gravitational, electrical etc)
Earth forces (wind, magnetic, kinetic, gravitational, electrical etc)
Solar radiation (for sustaining life, growing crops, solar and thermal power)
Climate (for agriculture, sustaining life, etc)
Water (seas, rivers, lakes, waterfalls, glaciers, and other watercourses etc) for sustaining life
Air (and its constituent gases) for sustaining life
Geothermal energy (source of heat) - Metals and minerals (e.g, iron, copper, diamond, petroleum etc)
Metals and minerals (e.g, iron, copper, diamond, petroleum etc)
Wildlife (marine- and terrestrial-based life) - Forests and other vegetation (enjoyment, source of food, timber etc)
Forests and other vegetation (enjoyment, source of food, timber etc)
Areas of natural beauty (mountains, moorlands, savannah, tundra and other types of land).
People (labour and populations). - Some of the above-listed resources can be used or processed to make other products; this has occurred since humans first appeared on the planet, particularly to create shelter or other goods that facilitate human existence.
Some of the above-listed resources can be used or processed to make other products; this has occurred since humans first appeared on the planet, particularly to create shelter or other goods that facilitate human existence.
Every human-made item is made from natural resources: clay is made into bricks, iron and carbon are combined to form steel, sand (silica) is used to make glass and so on.
Habitat - Grey-heron-3300948 640.jpg
Grey-heron-3300948 640.jpg -
A habitat is a place in which a particular plant or animal lives. It is often used in the wider sense referring to major assemblages (a group of species found in the same location) of plants and animals found together. Ref Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018
A habitat survey is an ecological assessment method which evaluates the existing ecological value of a site and identifies any ecological constraints to a proposed development. For more information see: Habitat survey.
The Habitat Suitability Index is a numerical index providing an evaluation of habitat quality and quantity for a particular species, where a value of one represents optimum habitat and a value of zero represents a habitat of no value.
Sensitive ecological habitat is: Habitat that is threatened, endangered, or particularly vulnerable to changes in the local ecology. Examples include, but are not limited to, wetlands, dunes, old growth forests, and native prairies.' Ref The Living Building Challenge 4.0, A Visionary Path to a Regenerative Future, published by the International Living Future Institute in June 2019.
The National Planning Policy Framework (NPPF) Annex 2: Glossary, published by the Ministry of Housing, Communities & Local Government (MHCLG) in 2012, defines irreplaceable habitat as: 'Habitats which would be technically very difficult (or take a very significant time) to restore, recreate or replace once destroyed, taking into account their age, uniqueness, species diversity or rarity. They include ancient woodland, ancient and veteran trees, blanket bog, limestone pavement, sand dunes, salt marsh and lowland fen.'
Ecological baseline - The ecological baseline is the ecological value of a site before construction works are undertaken. It can be compared to the ecological value of the site after construction works are complete to determine where there have been changes.
The ecological baseline is the ecological value of a site before construction works are undertaken. It can be compared to the ecological value of the site after construction works are complete to determine where there have been changes.
In this context, ecological value is the importance, worth, or usefulness of a species, habitat or ecosystem in terms of its impact on other species and / or habitats, as well as other environmental, social, cultural and economic value that can be delivered from species and habitats and their interactions, specific to a geographical frame of reference.
Ref Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018.
Wavelength - Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines wavelength as: The distance between successive crests of an electromagnetic wave; the inverse of frequency.
Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines wavelength as: The distance between successive crests of an electromagnetic wave; the inverse of frequency.
The term wavelength may also be used more generally to describe the spatial period of any periodic wave, that is, the distance over which the shape of the wave repeats.
Consumable - The Living Building Challenge 4.0, A Visionary Path to a Regenerative Future, published by the International Living Future Institute in June 2019, defines consumables as: Non-durable goods that are likely to be used up or depleted quickly. Examples include office supplies, packaging and containers, paper and paper products, batteries, and cleaning products.
The Living Building Challenge 4.0, A Visionary Path to a Regenerative Future, published by the International Living Future Institute in June 2019, defines consumables as: Non-durable goods that are likely to be used up or depleted quickly. Examples include office supplies, packaging and containers, paper and paper products, batteries, and cleaning products.
This is as opposed to durables, which are: Goods that have utility over time rather than being depleted quickly through use. Examples include appliances, electronic equipment, mobile phones, and furniture.
Timbering - Timbering is a method of providing temporary support to the side of a trench and is sometimes called planking and strutting.
Timbering is a method of providing temporary support to the side of a trench and is sometimes called planking and strutting.
The Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018, defines service life as: The period of time after installation during which a building, or its part, meets or exceeds the performance requirements. Ref: BSI, BCIS. 2008. PD 156865. Standardized Method of Life Cycle Costing for Construction Procurement. s.l. : BSi, 2008.
See also: Service life of products. -
--BRE Group -
NB Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines service life as: The period of time after construction or refurbishment when an asset meets or exceeds its functional performance requirements.
It defines residual service life as: Service life remaining at a certain moment of consideration (also known as residual life).
Pavement - Pavement.jpg
Pavement.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of pavement
2 Types of pavement - 2.1 Flexible paving
2.1 Flexible paving - 2.2 Rigid paving
2.2 Rigid paving - 2.3 Pavers
2.3 Pavers - 2.4 Small unit pavers
2.4 Small unit pavers - 2.5 Cobblestones
2.5 Cobblestones - 2.6 Setts
2.6 Setts - 2.7 Interlocking grids
2.7 Interlocking grids - 2.8 Tactile paving
2.8 Tactile paving - 2.9 Green paving
2.9 Green paving - 3 Other definitions
3 Other definitions - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - 5 External references
5 External references - Introduction
Introduction - Pavements are a form of exterior surface covering, typically raised and used by pedestrians, running parallel to, and on either side of a road. They provide an area that is separated from, and so protected from vehicular traffic. However, the term can also be used to refer to other paved areas, such as pedestrianised streets, patios, courtyards, driveways, and so on.
Pavements are a form of exterior surface covering, typically raised and used by pedestrians, running parallel to, and on either side of a road. They provide an area that is separated from, and so protected from vehicular traffic. However, the term can also be used to refer to other paved areas, such as pedestrianised streets, patios, courtyards, driveways, and so on.
Pavements can be constructed using asphalt, concrete, flagstone, cobblestone, artificial stone, bricks, tiles and timber.
The term paver or paviour (pavior in the USA) refers to a paving stone, tile, brick or piece of concrete used to form a pavement surface. They are usually laid to a fall of 1:60 or more to drain water to one or both sides. They are usually built to a minimum width of 1.2 m where this is possible.
The main British and European Manufacturing Standards relating to paving are:
BS EN 1338: Concrete paving blocks. - BS EN 1339: Concrete paving flags.
BS EN 1339: Concrete paving flags. - Types of pavement
Types of pavement - Flexible paving
Flexible paving - This may consist of the following layers:
This may consist of the following layers: -
100 mm blinded and consolidated hardcore. - 40 mm thick base course of coated macadam.
40 mm thick base course of coated macadam.
20 mm thick wearing course of coated macadam.
Rigid paving - This may consist of the following layers:
This may consist of the following layers: -
75 mm thick consolidated hardcore. - 75 mm thick plain insitu concrete with contraction and expansion joints.
75 mm thick plain insitu concrete with contraction and expansion joints.
Pavers - This may consist of the following layers:
This may consist of the following layers: -
75 mm thick consolidated hardcore. - 25 mm thick dry cement/sand bed.
25 mm thick dry cement/sand bed.
600 x 600 x 50 mm precast concrete pavers laid with butt joints filled with mortar.
Small unit pavers - This may consist of the following layers:
This may consist of the following layers: -
100 mm thick consolidated hardcore. - 50 mm thick bed of sharp sand.
50 mm thick bed of sharp sand. - 60 mm thick precast concrete plain or interlocking pavers vibrated into bed with sand-filled joints.
60 mm thick precast concrete plain or interlocking pavers vibrated into bed with sand-filled joints.
Cobblestones - Cobbles.jpg
Cobbles.jpg -
Cobblestone were frequently used in early pavement construction. They are small stones or pebbles that were traditionally gathered from stream beds and hence had been rounded and smoothed by water. They are usually set in sand or bound together with mortar.
Setts - Setts.jpg
Setts.jpg -
Setts are rectangular stones, usually made of granite, often used in landscape architecture as they can be arranged in various decorative ways with different patterns and colours.
The second edition of The Dictionary of Urbanism by Rob Cowan, published in 2020, suggests that a sett is: A small rectangular quarried stone used for paving. Setts are often popularily called cobbles (see cobbled). Wooden and rubber setts have also occasionally been used.'
A Belgian block is: A cubical paving block; a sett
Interlocking grids - Interlockingpavement.jpg
Interlockingpavement.jpg -
These are concrete or stone units with open, permeable spaces between them.
Tactile paving - Tactile paving.jpg
Tactile paving.jpg -
These come in a variety of forms and are commonly used in urban areas as a means of hazard warning for visually-impaired pedestrians at kerb edges, road crossings and gradient changes. They can also be used on cycle paths as a way of demarcating the area to be used by cyclists.
For more information, see Hazard warning surfaces.
Green paving - Pavegen270.jpg
Pavegen270.jpg -
New products are being developed that incorporate technology with to make pavements smarter and greener. For example, see Pavegen.
Other definitions - The second edition of The Dictionary of Urbanism by Rob Cowan, published in 2020, suggests that pavement can mean:
The second edition of The Dictionary of Urbanism by Rob Cowan, published in 2020, suggests that pavement can mean:
'(UK) The raised surface for pedestrians beside a street or road. The US equivalent is sidewalk, though pavement is used in some parts of the southern states.
(US, and UK highway engineers) The structure of a road, including its surface and underlying foundations. The general UK equivalent is roadway.
A paved surface. - An alley.
An alley. -
Clay in construction - Clay is a finely-grained natural rock or soil material that, along with other materials such as stone and wood, has been used as for construction for thousands of years. It is composed of one or more clay minerals (such as kaolinites or smectites), sometimes with small quantities of quartz, metal oxides and organic matter. Clay is formed very slowly as a result of the weathering and erosion of rocks containing the mineral group known as feldspar.
Clay is a finely-grained natural rock or soil material that, along with other materials such as stone and wood, has been used as for construction for thousands of years. It is composed of one or more clay minerals (such as kaolinites or smectites), sometimes with small quantities of quartz, metal oxides and organic matter. Clay is formed very slowly as a result of the weathering and erosion of rocks containing the mineral group known as feldspar.
Due to the particle size (typically, a grain size of less than 4 micrometres (m)), and water content, clays have a high plasticity until they are dried or fired, at which point they become hard and brittle.
Classified as a fine soil, clay has the following characteristics:
Dry lumps can be broken but not powdered between fingers.
It is smooth to the touch. - It shrinks on drying which usually leaves cracks.
It shrinks on drying which usually leaves cracks.
Its particles have intermediate to high plasticity. - It has a sand or gravel content of less than 35%.
It has a sand or gravel content of less than 35%.
Its compactness is soft. - Its structure can be fissured, intact, homogeneous, inter-stratified, or weathered.
Its structure can be fissured, intact, homogeneous, inter-stratified, or weathered.
Clay is used around the world as a construction material, most commonly baked into brick or roof tiles. The relative ease with which clay can be extracted from the ground and processed e.g. by adding water to change its shape, or increasing its strength by adding straw, sand, etc. means that it can be considered 'sustainable'. In addition, it provides relatively good thermal insulation and thermal mass.
Clay is also an important ingredient in composite materials such as adobe, cob, rammed earth, wattle and daub, clay plaster, clay mortar, ceramics, and so on.
Clay has good robustness, stability and durability. It is fire-resistant and capable of withstanding seismic activity, giving it a potential lifespan of 100 years or more.
Topsoil - Topsoil is the upper layer of a soil profile, usually darker in colour (because of its higher organic matter content) and more fertile than subsoil, and which is a product of natural
Topsoil is the upper layer of a soil profile, usually darker in colour (because of its higher organic matter content) and more fertile than subsoil, and which is a product of natural
biological and environmental processes. Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
Topsoil is typically between 5 - 20 cm (2 - 8 inches) deep. It can also be measured as the depth from the surface level to the subsoil, i.e. the distance to the first densely-packed layer of soil.
The topsoil is where the majority of the biological soil activity occurs, as it contains the highest concentration of organic matter and microorganisms, due to decomposition from animals, plants, and so on. The topsoil contains the highest concentration of plant roots, as plants acquire the majority of their nutrients from the topsoil layer.
The main elements that make up topsoil composition are:
Organic matter. - Mineral particles.
Mineral particles. - Water.
Water. - Air.
Air. - The soils strength and bearing capacity depends on its skeletal structure and decreases with the presence of organic matter.
The soils strength and bearing capacity depends on its skeletal structure and decreases with the presence of organic matter.
Water run-off results in minerals from the topsoil migrating down into the subsoil which can lead to mineral deficiencies in the topsoil. The knock-on effect of this is that roots have to dig deeper for nutrients. During construction it can be necessary to strip topsoil, although it should be considered that by exposing the subsoil, the rate of erosion of soil minerals increases.
Construction work can lead to the organic matter of topsoil condensing and settling in different ways, such as in roadbeds and foundations.
Pedestrian - The term pedestrian refers to a person travelling on foot, generally on a road or pavement. This can include people that are walking or running. The term pedestrianised refers to an area (typically a street) that has been adapted so it is only used by pedestrians and not motor vehicles.
The term pedestrian refers to a person travelling on foot, generally on a road or pavement. This can include people that are walking or running. The term pedestrianised refers to an area (typically a street) that has been adapted so it is only used by pedestrians and not motor vehicles.
Accessible - The building regulations, set out legal requirements for specific aspects of building design and construction. A series of approved documents provide general guidance about how different aspects of building design and construction can comply with the building regulations.
The building regulations, set out legal requirements for specific aspects of building design and construction. A series of approved documents provide general guidance about how different aspects of building design and construction can comply with the building regulations.
Approved document M provides guidance for satisfying Part M of the building regulations: Access to and use of buildings, which requires the inclusive provision of ease of access to, and circulation within, buildings, together with requirements for facilities for people with disabilities.
Approved document M, Volume 2: Buildings other than dwellings, suggests that the word accessible with regards to buildings or parts of buildings means:
that people, regardless of disability, age or gender are able to gain access.
Facility - The New Rules of Measurement (NRM) are published by the Royal Institute of Chartered Surveyors (RICS). They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects.
The New Rules of Measurement (NRM) are published by the Royal Institute of Chartered Surveyors (RICS). They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects.
According to NRM3: Order of cost estimating and cost planning for building maintenance works, the term facility means:
the built asset as a whole or part, including the site and building/structure and appropriate block, floors, space, zone, room, systems, assets, components, and sub-components.
Culture - Books-2463779 640.jpg
Books-2463779 640.jpg -
Culture is a society or communitys acquired body of knowledge, a multi-faceted phenomenon that is the product of civilisation and considered central to the study of anthropology. It comprises entities that are primarily associated with the arts and social sciences but can also include science, technology and other concepts such as:
Customs and ways of doing things - Social conventions
Social conventions - Language
Language - Laws
Laws - Literature
Literature - Arts and crafts
Arts and crafts - Architecture
Architecture - Music
Music - Dance
Dance - Philosophy
Philosophy - Religion
Religion - Military
Military - Cuisine
Cuisine - Technological prowess
Technological prowess - Beliefs.
Beliefs. - Attitudes to sex
Attitudes to sex - Economic
Economic - Business
Business - Many of the above are a posteriori concepts acquired through learning and experience. Different cultures associated with different races may embody all of the above or just have developed prowess in a few: one society may not be religious while another may see it as a core cultural component. One society or community may have evolved into a highly complex one with heightened cultural awareness which may be differentiated from another that is a less complex society.
Many of the above are a posteriori concepts acquired through learning and experience. Different cultures associated with different races may embody all of the above or just have developed prowess in a few: one society may not be religious while another may see it as a core cultural component. One society or community may have evolved into a highly complex one with heightened cultural awareness which may be differentiated from another that is a less complex society.
Ethnic groups frequently use their cultures as a way to differentiate themselves by highlighting a distinguishing aspect such as musical development, conventions of dance, literary achievements or technological advancement.
The growth of culture is a slow process that develops as society progresses, from primeval beginnings to what is regarded today as advanced culture. As societies progress, their cultures become enlarged and enriched.
Cultural interaction is a phenomenon of globalisation and the modern world generally, given the plethora of communication technologies through which global communities can interact with each other. Culture feeds off culture: one society may adapt to its own liking the habits and techniques of another culture thereby creating new cultural possibilities.
Cultures can also spawn subcultures. These arise when a group of people within a culture create a variation to differentiate themselves from their parent culture and which may be regarded as subversive by the other members of the society.
Subcultures typically have their own rules regarding values, honour, sex, work etc and can be associated with young people who wish to rebel against society. They differ from countercultures whose values are often substantially different to mainstream society.
A cultured person is usually one who has achieved a well-rounded level of knowledge in either the arts or sciences or both, and may be au fait with current affairs.
The term 'culture' can also be used in a local setting. For example, the 'culture' at a company may allow relaxed dress codes.
Community - UK gov garden communities 24088.png
UK gov garden communities 24088.png -
In very general terms, the word community refers to a group of people who live in same location, often sharing housing, amenities, services, infrastructure, and so on. They may have shared interests in how their local area is managed, developed, regenerated, conserved, and so on. Communities can range from the very small scale social units, relating to a single building, up to the city, national or even global scale.
The term can also be used in a wider sense to refer to people with shared interests or professional status, such as, an engineering community or building community.
The word 'community' is derived from the Latin 'communis', meaning 'shared in common'
Engaging with the local community is of growing importance within the planning system. The Coalition Government created the Localism Act which made public consultation a statutory requirement for specific schemes of a certain size, or specific organisations. For more information, see Consultation process.
A community liaison officer (CLO), sometimes referred to as a local liaison officer, communicates and coordinates activities between an organisation and a community. Typically, this might be required where an organisation such as a property developer has a significant interaction with the general public. For more information, see Community liaison officer.
Developers are increasingly attempting to create new communities rather than simply buildings, through techniques such as placemaking.
Section 18 of the Planning and Compulsory Purchase Act 2004 introduced a requirement for local planning authorities to prepare a statement of community involvement (SCI). The SCI sets out the authoritys engagement strategy for the planned involvement of the local community in the preparation and review of development plan documents and in consultation on planning applications. For more information, see Statement of community involvement.
The Localism Act 2011 also brought in a range of new rights for communities and neighbourhood groups. These community rights included:
Community Right to Bid. - Community Right to Challenge.
Community Right to Challenge. - Community Right to Build.
Community Right to Build. - Community Right to Reclaim Land.
Community Right to Reclaim Land. - Right to Contest.
Right to Contest. - New neighbourhood planning measures.
New neighbourhood planning measures. - The Our Place programme.
The Our Place programme. - Community shares initiative.
Community shares initiative. - Tenant empowerment programme.
Tenant empowerment programme. - Right to Transfer.
Right to Transfer. - Community-led housing is a means by which local communities can play a central role in providing their own housing. This can be used to specifically help certain groups such as older people. The general concept behind community-led housing is that the housing can be rented to people who live in the local community at affordable rates. For more information, see Community-led housing.
Community-led housing is a means by which local communities can play a central role in providing their own housing. This can be used to specifically help certain groups such as older people. The general concept behind community-led housing is that the housing can be rented to people who live in the local community at affordable rates. For more information, see Community-led housing.
The Community infrastructure levy (CIL) is a charge that local authorities can choose to impose on new developments to fund local infrastructure. For more information, see Community infrastructure levy.
Community energy networks have become a popular means by which local communities can take collective action to reduce energy consumption by taking collective action to improve buildings, use collective purchase purchasing or switching power to get a better deal, and so on. For more information, see Community energy network.
Cohousing - Contents
Contents - [hide]
[hide] - 1 Introduction to Cohousing
1 Introduction to Cohousing - 2 Case study: Marmalade Lane
2 Case study: Marmalade Lane - 3 Related articles on Designing Buildings Wiki
3 Related articles on Designing Buildings Wiki - 4 External references
4 External references - Introduction to Cohousing
Introduction to Cohousing - Cohousing is a method of living that has become established in several countries around the world. Created and run by residents, cohousing developments are communities where people not only know their neighbours but actively manage their neighbourhood alongside them.
Cohousing is a method of living that has become established in several countries around the world. Created and run by residents, cohousing developments are communities where people not only know their neighbours but actively manage their neighbourhood alongside them.
Small enough that everyone can be familiar with each other, but large enough not to force them to be, cohousing communities are built around a shared desire for a sense of belonging, neighbourliness and mutual support that many people feel is missing from modern life and contemporary housing developments.
In cohousing communities, just as in conventional neighbourhoods, residents own or rent their own private homes. But everyone also benefits from extra shared facilities and spaces that allow members to do things together. Shared outdoor spaces provide opportunities to grow food, play and be close to nature, and a shared Common House provides additional indoor space for residents to meet, eat and socialise together. Car parking tends to be kept to a minimum and located at the periphery, allowing the central spaces close to homes to be used for other things.
Cohousing2.jpg -
Living in a cohousing community brings a few extra responsibilities residents are encouraged to be actively involved in running the place but many more benefits. This way of living is part of mainstream housing development in many European countries and has a growing presence in the US. In the UK there are several completed purpose-built cohousing schemes and many more in the planning or delivery stages.
The UK Cohousing Network is the principal resource for cohousing groups in the UK and its website lists dozens of active cohousing groups across the country. While many are open to all and actively seek a generational mix, some may be exclusively for older people. Some are new build; others conversions of existing property. All cohousing projects tend to have a strong focus on engendering more sustainable ways of living.
Case study: Marmalade Lane - Marmalade Lane - formerly known as K1 - is one of a growing number of cohousing schemes being realised in the UK.
Marmalade Lane - formerly known as K1 - is one of a growing number of cohousing schemes being realised in the UK.
Marmalade Lane is a cohousing project that is being delivered in Orchard Park, Cambridge. The site was owned by Cambridge City Council, who following the 2007-8 financial crisis took the decision to use its landholding to bring forward an alternative form of community-led housing development.
Cambridge City Council supported Cambridge Cohousing Limited (CCL) in bringing forward plans for a new cohousing development. Working with advisors Instinctively Green and Cambridge Architectural Research, CCL prepared a detailed design brief for the scheme.
In 2015, Cambridge City Council and CCL ran a competitive tendering process to select an enabling developer for the project. It selected a partnership between UK developer TOWN, and Swedish housing manufacturer Trivselhus.
Detailed planning permission was obtained in 2016, the result of many months collaboration between the developer, Mole Architects and the CCL group. The developer and its design team worked closely with future residents on every aspect of the scheme, including the masterplan, design of the dwellings, energy strategy and landscape plan.
The local planning authority, South Cambridgeshire District Council, is one of 11 custom build vanguard authorities selected by the government to pioneer custom build and self build housing.
Cohousing3.jpg -
Marmalade Lane comprises a series of terraces together with a purpose-build apartment block, laid out around a large central shared garden. The centrally-located Common House will provide a large dining area, catering kitchen, laundry and a range of ancillary spaces and facilities for the group to use.
Homes range from 47 sq. m one-bedroom flats to 128 sq. m five-bedroom houses. TOWNs custom build system has allowed residents to select their basic house type and configure the interior from a menu of floor plan options, allowing a high degree of customisation and a wide variety of dwelling sizes from a single system. Residents also have the opportunity to choose their external brickwork from a pre-selected palette of bricks.
Built with Trivselhuss Climate Shield system, a closed-panel timber construction system manufactured in Sweden, the scheme will offer residents very low running costs and close-to-Passivhaus energy performance standards.
With construction having commenced in June 2017, Marmalade Lane residents expect to move in mid-2018.
Resident - Students2.jpg
Students2.jpg -
A resident is an individual who uses a particular place as a residence on a permanent or long-term basis. A residence is typically a flat or a dwellinghouse.
A resident can be a tenant, i.e. someone who occupies a residence that they rent from a landlord, or they can own the freehold to the residence, i.e. they have the title absolute of the property.
A resident can also be considered to be part of a household which, according to the Household Projections: England prepared by the Department for Communities and Local Government, is defined in the 2011 Census as:
one person living alone; or a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room or sitting room or dining area.
The term resident is also used to refer to citizens of countries, i.e. the right of residence, which affects whether or not an individual has the right to remain in the country, the obligation to pay tax, the right to medical care, and so on. In the UK, someone is classed as a resident if:
They spend 183 or more days in the UK in a tax year.
Their only home is in the UK (they must have owned, rented or lived in the home for at least 91 days in total), and within a tax year they spend at least 30 days there.
A resident differs from an occupier (or occupant) as this refers more widely to person/s and organisations who use any property for residential or commercial purposes.
NB The Explanatory Notes to the Draft Building Safety Bill, published by the Ministry of Housing, Communities & Local Government on 20 July 2020, defines a resident of a dwelling as: a person who lawfully resides there, regardless of tenure.
It defines a resident engagement strategy as: '....the means by which those living in buildings covered by the new regulatory regime can get more involved in the decision-making in relation to the safety of their homes. It will set out the approach and the activities that the Accountable Person will undertake to deliver these opportunities for all residents to participate.'
A residents' panel is: 'A statutory committee to be set up by the Building Safety Regulator. The residents panel will be made up of residents and representatives/advocates of residents, and advise the Building Safety Regulator on strategy, policy, systems and guidance which will be of particular interest to residents of higher-risk buildings.'
End-user - Students2.jpg
Students2.jpg -
In the construction industry, the term user or users typically refers to any persons, groups or organisations who use property or land as an occupier, owner, tenant, visitor or other stakeholder.
For more information see: Users. -
A user can also be referred to as an end-user, which indicates that the end is the completion of building, i.e. when it can be used for its designed purpose. A common domestic building end-user is a resident, that is, an individual who uses the building as a residence on a permanent or long-term basis.
The type of end-users will depend on the use class of a building, i.e. what it is used for. The Town and Country Planning (Use Classes) Order categorises uses of land and buildings. Developments may not be used for purposes that are not within the use class for which they received planning permission.
Domestic building - House-construction.jpg
House-construction.jpg -
The term 'domestic building' refers to a dwelling that has no more than one family unit resident in it, and which is used as a place of permanent or semi-permanent habitation.The most common example of a domestic building is a house.
The term non-domestic building refers to any building that is not a domestic building.
A domestic building tends to be home to a household, which was defined in the 2011 Census as being: one person living alone; or a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room or sitting room or dining area.
By contrast, the term residential building has a wider application and can be used to refer to blocks of flats, homes of multiple occupancy (HMOs), institutions (e.g. hospitals, care homes, prisons), hotels, hostels, student halls of residence, and so on.
Apartment - Apartment.jpg
Apartment.jpg -
The term apartment refers to a self-contained housing unit that occupies only part of a building, typically, on a single level. It is generally associated with North American real estate, although apartments have been common as far back as the Roman times. The term itself is thought to have originated in the mid-17th century, from the French word appartement derived from the Italian appartamento in turn derived from appartare', meaning to separate.
In North America, apartments are typically leased. Residential blocks in which the residents own their accommodation are generally referred to as condominiums.
The term apartment is sometimes considered to be synonymous with the term flat commonly used in the UK. However, Approved document B, Fire Safety, Volume 1 Dwelling houses, defines a flat specifically as; 'a separate and self-contained premises constructed or adapted for use for residential purposes and forming part of a building from some other part of which it is divided horizontally.' and suggests that this '...includes live/work units, i.e. a flat intended to serve as a workplace for its occupants and for persons who do not live on the premises.
For more information see: Flat definition. -
In the UK, the term duplex refers to an apartment (not a house) that includes two floors of accommodation, joined by an internal staircase. Historically, this would have been referred to as a maisonette, but the term duplex has become increasingly popular because of its perceived Americanism, and is generally applied to apartments with a more modern design, whereas a maisonette might be more traditional.
For more information see: Duplex. -
The term 'penthouse' is used to describe an apartment on the top floor of a high-rise building. According to the New York City building code, a penthouse is ...an enclosed structure on or above the roof of any part of a building, which is designed or used for human occupancy. Penthouses are frequently the largest, most luxurious, and therefore the most expensive, apartments in a building.
Household definition - Family-2611748 640.jpg
Family-2611748 640.jpg -
According to the Household Projections: England prepared by the Department for Communities and Local Government, a household, as defined in the 2011 Census is:
one person living alone; or a group of people (not necessarily related) living at the same address who share cooking facilities and share a living room or sitting room or dining area.
The previous definition used in the 2001 Census was:
one person living alone or a group of people (not necessarily related) living at the same address with common housekeeping that is, sharing either a living room or sitting room or at least one meal a day.
The definition was altered to take into account social changes and modern living arrangements.
The National Statistics harmonised survey definition of a household is:
One person or a group of people who have the accommodation as their only or main residence AND (for a group):
either share at least one meal a day, or
share the living accommodation, that is, a living room or sitting room.
The occupant(s) of a bedsit who do not share a sitting or living room with anyone else comprise a single household.
NB: From April 2001, Government surveys, replaced the traditional concept of the "head of the household" (HOH) with a "household reference person" (HRP). See household reference person for more information.
In July 2018, an NHBC report, 'The changing shape of UK households' published the following key facts about UK households in 2017:
3.4 milion number of households with 20 to 34-year olds living with parents.
57% - proportion of households consisting of just one or two adults.
39% - proportion of households with children.
4%- proportion of other household types, eg. House share, multigenerational living.
28% - proportion of people living alone.
10% - proportion of single-parent families. - (Ref. http://www.nhbc.co.uk/media-centre/articles/pressreleases/changing-shape-of-uk-households/)
(Ref. http://www.nhbc.co.uk/media-centre/articles/pressreleases/changing-shape-of-uk-households/) -
The English Housing Survey, Energy efficiency, 2018-19, published by the Ministry of Housing, Communities & Local Government in July 2020 suggests the main classification of household type uses the following categories:
Couple no dependent child(ren). - Couple with dependent child(ren).
Couple with dependent child(ren). - Couple with dependent and independent child(ren).
Couple with dependent and independent child(ren).
Couple with independent child(ren). - Lone parent with dependent child(ren).
Lone parent with dependent child(ren).
Lone parent with dependent and independent child(ren).
Lone parent with independent child(ren).
Two or more families. - Lone person sharing with other lone persons.
Lone person sharing with other lone persons. - One male.
One male. - One female.
One female. -
Living room - Even the earliest dwelling, whether a cave or a hut, provided an area for living, whether part of a central space or subsequently, an area that was sectioned off. A combined area for eating, sleeping and talking, the earliest living areas eventually became separate entities known today as the living room (or sometimes sitting room or lounge).
Even the earliest dwelling, whether a cave or a hut, provided an area for living, whether part of a central space or subsequently, an area that was sectioned off. A combined area for eating, sleeping and talking, the earliest living areas eventually became separate entities known today as the living room (or sometimes sitting room or lounge).
In the Saxon hall house, one central area functioned as a space for socialising, sleeping, cooking, eating and entertaining. With time, one end of the house would be sectioned off as a raised sleeping area; the other end might have separate areas for service rooms such as for working or storage, or for a pantry or buttery; the large space in the middle remained the central living area.
In the medieval Wealden house, the living area was first called a chamber or bower, subsequently a parlour a name derived from the habit of monks in monasteries to receive guests in a special room where they could talk (French: parler).
In Renaissance Italy, the living room was often located on the first floor the piano nobile (or noble floor) above the din and smell of the street. However, in England the parlour was more often located on the ground floor, with the upper floors reserved for sleeping and washing. This tradition would continue through Georgian and Victorian times and beyond, extending even to the present day.
Throughout these periods, with the separation of cooking, eating and washing functions, the parlour became a space for relaxation and socialising, a term which the Victorian lower middle classes would continue to use; the upper middle class had their own term to reflect the activity that would sometimes be carried out there the drawing room. These rooms, which today would be called living rooms, usually housed the familys best furniture and most valuable belongings, perhaps even a piano.
Some Victorian parlours would be highly decorated every surface covered in elaborate patterns flock paper on the walls, highly patterned furnishings, intricate carpet, and even tapestries, perhaps made by the lady of the house. The focus of the parlour or drawing room would have been the open fire comprising a cast-iron grate and fire surround which could be plain or elaborate.
The Garden City movement, whose roots can be discerned in the late 1890s, brought a new approach to the parlour or sitting room as it was also called. One of the key aims of the designs of this period, which included the housing at Letchworth, was to allow maximum natural light to penetrate the house in stark contrast to the often-gloomy Victorian interior. One way of achieving this was to introduce an early form of open planning by removing the divisions between font and back rooms on the ground floor, a living room/kitchen with windows at both ends was created. This idea that the home did not necessarily have to be divided into a series of small, dark rooms was to gain momentum in the ensuing years and would have a huge influence on the modernists of the early 20th century.
Given the highly varied stock of architectural house styles that can be seen throughout Britain, a living room or living area is likely to be a well-defined room or a larger open-plan area which includes kitchen and dining areas. What it has in common with the past periods is that it will very likely contain a familys most expensive items whether in the form of furnishings, paintings or entertainment technology. In terms of style, an uncluttered simplicity with plain-coloured surfaces has become popular, largely thanks to the influence of design features in magazines, the internet and on television.
The terms parlour, drawing room, sitting room and reception room have been almost completely superseded by living room; these terms are still seen in estate agents sales literature which often tries to evoke the grandeur of bygone eras.
Common area - The term common area refers to areas and amenities which are provided for the common use of more than one person. Where there is a tenancy in common, such as a in a residential building complex, the common areas can be used by all tenants, with no one individual possessing more control over, or right to them than another.
The term common area refers to areas and amenities which are provided for the common use of more than one person. Where there is a tenancy in common, such as a in a residential building complex, the common areas can be used by all tenants, with no one individual possessing more control over, or right to them than another.
This is different from common land which, in English law, refers to registered land on which individuals have rights in common.
Examples of common areas include: -
Car parks and access ramps. - Corridors.
Corridors. - Hallways.
Hallways. - Lobbies and reception areas.
Lobbies and reception areas. - Stairways.
Stairways. - Roofs.
Roofs. - Lifts.
Lifts. - Fire escapes.
Fire escapes. - Gutters and downpipes.
Gutters and downpipes. - Gardens, yards etc.
Gardens, yards etc. - Entrances and paths leading to entrances.
Entrances and paths leading to entrances. - Amenities such as kitchens, fitness facilities, store rooms, laundry rooms, etc.
Amenities such as kitchens, fitness facilities, store rooms, laundry rooms, etc.
Recreational areas. - In a residential building, tenants are typically jointly responsible for the up-keep and maintenance of common areas. However, building owners may employ a building or facilities manager to maintain them. Depending on the level of up-keep, it can be advisable for tenants to arrange meetings at certain times throughout the year to discuss the maintenance of the common areas.
In a residential building, tenants are typically jointly responsible for the up-keep and maintenance of common areas. However, building owners may employ a building or facilities manager to maintain them. Depending on the level of up-keep, it can be advisable for tenants to arrange meetings at certain times throughout the year to discuss the maintenance of the common areas.
Common parts are defined as: 'Those parts of domestic properties (such as a block of flats) which are used in common by the occupants of more than one flat (such as the corridors and fire-escape routes)' in A reformed building safety regulatory system, Government response to the Building a Safer Future consultation, Ministry of Housing, Communities and Local Government, April 2020.
The Housing Grants, Construction and Regeneration Act 1996 (HGRA - also known as the Construction Act) suggests that common parts refers to: ...the structure and exterior of the building and common facilities provided, whether in the building or elsewhere, for persons who include the occupiers of one or more flats in the building.
Dead end - Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), suggests that a dead end is:
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), suggests that a dead end is:
An area from which escape is possible in one direction only.
Volume - Volume.jpg
Volume.jpg -
The term volume generally refers to a measurement of a three-dimensional shape that is enclosed by a closed surface. It is used to specify the amount of space that a substance such as a solid, liquid or gas occupies.
As per the International System of Units (SI), the standard unit of volume is the cubic metre (m). The cubic metre measurement indicates the volume contained within a cube the edges of which are all 1 m long.
To be able to calculate the volume of simple shapes (e.g. regular, right angled, straight-edged), arithmetic formulae can be used, such as:
Volume = length x width x height -
Whereas, more complex shapes require integral calculus if there is a formula for the shapes boundary.
The term volume is also used in relation to sound levels, i.e. how loud or quiet a sound is. The higher the intensity of a sound, the louder it is perceived by the ear, and the higher its volume. Decibels (dB) are most commonly used as a measure of sound volume. The decibel scale gives an approximation of human perception of relative loudness.
Force - Hammer and egg 290.jpg
Hammer and egg 290.jpg -
In terms of physics, a force is an interaction that changes the motion of an object when it is unopposed. This takes the form of a push or a pull on an object. Forces only exist as a result of an interaction which causes an object with mass to change its velocity; when the interaction stops then the object no longer experiences the force. Since a force has both magnitude and direction, it is considered a vector quantity. Force is measured in the SI unit of Newtons, and represented by the symbol F.
The two broad categories of forces between objects are contact forces and forces that result from action-at-a-distance.
Contact forces are types of force that occur when the two interacting objects physically connect with one another. These include:
Friction: The force that resists the relative motion of solid objects, surfaces, fluid layers and material elements sliding against one another.
Tension: The force transmitted through a string, rope, cable or wire when pulled tight by oppositional forces.
Normal force: The support force exerted upon an object that is in contact with another stable object. For example, an object on the surface of a table is supported by an upward force being exerted by the table surface.
Air resistance: The frictional force air exerts against a moving object. This is also known as drag.
Applied force: A force applied to an object by a person or another object.
Spring force: A restoring force exerted by a spring, which acts to restore a spring towards equilibrium.
Action-at-a-distance forces occur when two interacting objects are not in physical contact with one another but still exert a push or pull. These include:
Gravitational force: The phenomenon by which all things with mass are brought toward one another.
Electrical force: The attractive or repulsive interaction between any two charged objects.
Magnetic force: The attraction or repulsion that arises between electrically charged particles due to their motion.
Structural analysis can be used to calculate the effects of forces acting on any component and on a structure overall.
Three properties of forces that should be considered are:
Magnitude: The size of the force. - Direction: The direction in which the force is acting.
Direction: The direction in which the force is acting.
Position: The position on which the force acts.
Isaac Newton developed three laws of motion: -
First law: An object will remain at rest or in uniform motion unless compelled to do otherwise by some external force acting on it.
Second law: A force is caused by an acceleration acting on an object.
Third law: Action and reaction are equal and opposite.
A shear force is a force applied perpendicular to a surface, in opposition to an offset force acting in the opposite direction. This results in a shear strain. For more information, see Shear force.
An uplift force is any upward pressure applied to a structure that has the potential to raise it relative to its surroundings. Uplift forces can be a consequence of pressure from the ground below, wind, surface water, and so on. For more information, see Uplift force.
Stiffness is the extent to which an element is able to resist deformation or deflection under the action of an applied force. In contrast, flexibility or pliability is a measure of how flexible a component is, i.e. the less stiff it is, the more flexible it is.
Elevations - Typical elevations drawing.png
Typical elevations drawing.png -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Alternative meaning
2 Alternative meaning - 3 Related articles on Designing Buildings Wiki
3 Related articles on Designing Buildings Wiki - 4 External references
4 External references - Introduction
Introduction - Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
In the construction industry, the term elevation refers to an orthographic projection of the exterior (or sometimes the interior) faces of a building, that is a two-dimensional drawing of the buildings faades. As buildings are rarely simple rectangular shapes in plan, an elevation drawing is a first angle projection that shows all parts of the building as seen from a particular direction with the perspective flattened. Generally, elevations are produced for four directional views, for example, north, south, east, west.
Simple elevation drawings might show: -
The outline of a building. - Openings such as doors and windows.
Openings such as doors and windows. - Roofing.
Roofing. - Projections such as eves and pipes.
Projections such as eves and pipes. - Level datums such as finished ground level and floor positions.
Level datums such as finished ground level and floor positions.
Key dimensions such as wall lengths and heights.
Exterior features such as decks, porches and steps.
Any portion of the foundation that may be visible.
Exterior wall and roof finishes. - However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
Elevations might be prepared for a number of reasons, including:
As part of a survey of existing buildings.
To create a record of a building. - To explore and communicate interior and exterior design options.
To explore and communicate interior and exterior design options.
To communicate construction information. - As part of an application for planning permission.
As part of an application for planning permission.
As part of an application for building regulations approval.
For sales and marketing. - Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
Floor plan - Workingdrawing.jpg
Workingdrawing.jpg - Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
Floor plans are a form of orthographic projection that can be used to show the layout of rooms within buildings, as seen from above. They may be prepared as part of the design process, or to provide instructions for construction, often associated with other drawings, schedules, and specifications.
Floor plans may include key dimensions and levels, and may also use, hatching, symbols and other standard annotations and abbreviations to indicate materials, fittings and appliances, and so on.
Depending on the size of the building, floor plans are typically drawn at scales of between 1:200 and 1:20. Different line types, colours and weights can be used to differentiate between the types of drawn information they include.
Floor plans can be drawn for whole buildings, a single floor of a building, or just a single room. The more detailed the floor plan is in terms of layout, fittings and so on, the more useful and instructive it will be for the project. However, if spaces are complex, it is normal for separate drawings to be prepared for different trades, such as electrical and lighting drawings, plumbing drawings, and so on.
The lower-right-hand corner of the sheet is typically reserved for a title block. This provides a space to record the name of the project, the name of the drawing, the scale, the originators name, the date, revision history, and so on.
The floor plan view should be roughly centred on the sheet, with the front of the building typically drawn along the lower side of the sheet. A north point may be included to show the orientation of the floor plan.
Typically, the outside walls are drawn first, to lay the plan out on the sheet, then the internal walls, then windows, doors, stairs, lifts, ramps, and so on, are added. An arrow is used to indicate the upward direction of stairs and ramps. It is usual for a faint dotted line to be drawn around stairs (or other openings) where they are open at ceiling level.
Rooms should be clearly labelled, with block lettering in the centre of each room. The correct symbols should be added for elements such as; appliances, fixed furniture, fittings, building services, and so on.
Electrical symbols should be added to the drawing, indicating; power sockets, light switches, wall and ceiling lights, detectors and alarms, extract fans, and so on.
Items that are ceiling mounted, are generally drawn on the floor below their place of installation.
Dimension may be added to indicate the size and location of key elements such as; rooms, fittings, appliances or fixtures, external walls, window and door openings, and so on.
Section lines may be added where there are section drawings associated with the floor plan. Grid references may also be added to help co-ordinate the floor plan with other drawings.
Some floor plans may include notional furniture to help gauge the likely size of circulation spaces.
If a window or door schedule is to be prepared, doors and windows may be labelled with a number or letter, corresponding to an item on the schedule.
Floor plans should not duplicate information that is presented in specifications or schedules because of the potential for conflict. Instead they should refer to the specification or schedule.
Common facilities in buildings - According to the International Property Measurement Standards (IPMS): Residential Buildings, published by the International Property Measurement Standards Coalition (IPMSC) in September 2016, common facilities are:
According to the International Property Measurement Standards (IPMS): Residential Buildings, published by the International Property Measurement Standards Coalition (IPMSC) in September 2016, common facilities are:
Those parts of a building providing shared facilities that typically do not change over time, including for example, circulation areas, stairs, escalators, lifts/elevators and motor rooms, toilets, cleaners cupboards, plant rooms, fire refuge areas, maintenance rooms and unallocated parking spaces.
Plant room - A plant room, (sometimes referred to as a mechanical room or boiler room), is a dedicated space containing the equipment required to provide or supply building services such as; ventilation, electrical distribution, water and so on.
A plant room, (sometimes referred to as a mechanical room or boiler room), is a dedicated space containing the equipment required to provide or supply building services such as; ventilation, electrical distribution, water and so on.
The size of a plant room is generally proportional to the size and type of building. Large buildings may have several plant rooms, or spaces that occupy one or more storeys and some plant rooms may have specific functions, such as; battery rooms, transformer rooms boiler rooms and so on.
Depending on the size of the building and the nature and complexity of the building services required, plant rooms may contain (amongst other things):
Air handling units. - Boilers and thermostats.
Boilers and thermostats. - Chillers and refrigeration units.
Chillers and refrigeration units. - Heat exchangers.
Heat exchangers. - Water heaters and tanks.
Water heaters and tanks. - Water pumps and pipework.
Water pumps and pipework. - Gas pipework.
Gas pipework. - Sprinkler distribution piping and pumps.
Sprinkler distribution piping and pumps. - Electrical equipment and control panels
Electrical equipment and control panels - Back-up electrical generators and compressors.
Back-up electrical generators and compressors. - Switch gear.
Switch gear. - Batteries.
Batteries. - ITC systems.
ITC systems. - Machinery for lifts.
Machinery for lifts. - Humidifiers.
Humidifiers. - Ducts and filters.
Ducts and filters. - Other heating, ventilation and air-conditioning (HVAC) equipment.
Other heating, ventilation and air-conditioning (HVAC) equipment.
Specialist equipment for swimming pools, laboratories, factories and so on.
Plant room equipment may be linked to a Building Automation and Control System (BACS).
When designing a plant room, the following points should be considered:
The ease of access for the maintenance and/or replacement of equipment when locating a plant room.
The ability to expand if required in the future.
The ability to expand the equipment in the room if required.
Ventilation requirements. - Where the plant is located externally and may be in view, screening devices may be required.
Where the plant is located externally and may be in view, screening devices may be required.
Floors should be low maintenance finish and comply with slip resistance standards.
Access should be restricted to authorised maintenance personnel.
Sound transmission should be minimised with acoustic attenuation if in close proximity to user rooms/spaces.
Escalator - Escalator1.jpg
Escalator1.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 1.1 History
1.1 History - 1.2 Speed
1.2 Speed - 1.3 Configurations
1.3 Configurations - 1.4 Design considerations
1.4 Design considerations - 2 Escalator components
2 Escalator components - 2.1 Landing platforms
2.1 Landing platforms - 2.2 Truss
2.2 Truss - 2.3 Balustrade
2.3 Balustrade - 2.4 Handrail
2.4 Handrail - 2.5 Tracks
2.5 Tracks - 2.6 Steps
2.6 Steps - 2.7 Motor
2.7 Motor - 3 Find out more
3 Find out more - 3.1 Related articles on Designing Buildings Wiki
3.1 Related articles on Designing Buildings Wiki - Introduction
Introduction - Escalators are mechanical devices used for transporting people vertically between different levels of buildings. Typically, they take the form of a moving staircase, consisting of a 'chain' of single-piece aluminium or stainless steel steps guided by a system of tracks in a continuous loop.
Escalators are mechanical devices used for transporting people vertically between different levels of buildings. Typically, they take the form of a moving staircase, consisting of a 'chain' of single-piece aluminium or stainless steel steps guided by a system of tracks in a continuous loop.
Escalators are commonly used in buildings where the movement of a large number of people is required, such as shopping centres, airports, transit systems, exhibition halls, hotels, arenas, public buildings, and so on.
They occupy the same physical space as a staircase, generally have no waiting time (other than during periods of congestion), allow a greater flow of people, and can be more practical than lifts. It is also possible for people to walk up or down escalators, if they are in a hurry, or if they break down.
A variation of the escalator is the moving walkway, which transports people horizontally.
History - The first escalator was patented by two Americans, Leamon Souder and Nathan Ames, in the mid-19th century. However, their patented designs were never manufactured.
The first escalator was patented by two Americans, Leamon Souder and Nathan Ames, in the mid-19th century. However, their patented designs were never manufactured.
It wasnt until the early-20th century that a working prototype designed by Charles Seeburger and Jesse Reno was produced. Their working model gained a lot of attention and was first installed in New York Citys department stores. In 1910, Seeburger and Reno sold their invention to the Otis Elevator Company.
Speed - The speed of escalators is constant and is generally around 0.3-0.6 m (1-2 ft) per second. This translates to around 27-55 m (90-180 ft) per minute. An escalator moving an average of 44 m (145 ft) per minute can transport over 10,000 people per hour, which is a considerably higher capacity than a standard lift system.
The speed of escalators is constant and is generally around 0.3-0.6 m (1-2 ft) per second. This translates to around 27-55 m (90-180 ft) per minute. An escalator moving an average of 44 m (145 ft) per minute can transport over 10,000 people per hour, which is a considerably higher capacity than a standard lift system.
Configurations - There are three basic configurations that are used for most common escalator systems:
There are three basic configurations that are used for most common escalator systems:
Parallel: Escalators positioned side-by-side, moving in opposite directions.
Criss-cross: Escalators moving in one direction are stacked, minimising space requirements.
Multiple parallel: A bank of two or more escalators, with differing directions.
Design considerations - There a number of factors that affect the design of escalator systems, including:
There a number of factors that affect the design of escalator systems, including:
The vertical and horizontal distance to be spanned.
The location. - Other building infrastructure.
Other building infrastructure. - Traffic patterns.
Traffic patterns. - Carrying capacity.
Carrying capacity. - Safety considerations.
Safety considerations. - Aesthetic preferences.
Aesthetic preferences. - Canary Wharf Escalators.JPG
Canary Wharf Escalators.JPG -
Escalator components - The following components make up an escalator system:
The following components make up an escalator system:
Landing platforms - These contain the curved sections of the tracks, in addition to the gears and motors. The floor plate provides space for users to stand before stepping onto the moving steps. The comb plate has a series of cleats (like the teeth of a comb), that mesh with matching cleats on the edges of the steps and minimise the gap between the stair and the landing.
These contain the curved sections of the tracks, in addition to the gears and motors. The floor plate provides space for users to stand before stepping onto the moving steps. The comb plate has a series of cleats (like the teeth of a comb), that mesh with matching cleats on the edges of the steps and minimise the gap between the stair and the landing.
Escalator2.jpg -
Truss - The structure that bridges the lower and upper landings, and carries the straight track sections. Steel or concrete supports connect the ends of the truss to the top and bottom landing platforms.
The structure that bridges the lower and upper landings, and carries the straight track sections. Steel or concrete supports connect the ends of the truss to the top and bottom landing platforms.
Balustrade - This is the structure supporting the handrail of the escalator and can be made of metal, sandwich panels or glass.
This is the structure supporting the handrail of the escalator and can be made of metal, sandwich panels or glass.
Handrail - The handrail moves courtesy of a chain connected to the main drive gear by a series of pulleys. It is generally made from a blend of synthetic polymers and rubber, and is designed to be very durable.
The handrail moves courtesy of a chain connected to the main drive gear by a series of pulleys. It is generally made from a blend of synthetic polymers and rubber, and is designed to be very durable.
Tracks - The step-wheel track for the front wheels of the steps, and the trailer-wheel track for the back wheels of the steps, cause the steps to form a staircase as they move from under the comb plate.
The step-wheel track for the front wheels of the steps, and the trailer-wheel track for the back wheels of the steps, cause the steps to form a staircase as they move from under the comb plate.
Steps - These are typically solid and made of die-cast aluminium or steel. They are cleated with comb-like protrusions that mesh with the comb plates. The steps are linked by a continuous metal chain that forms a closed loop.
These are typically solid and made of die-cast aluminium or steel. They are cleated with comb-like protrusions that mesh with the comb plates. The steps are linked by a continuous metal chain that forms a closed loop.
The steps, connected in series, always step level as they move. The steps create a flat platform at both the top and the bottom of the escalator by collapsing on each other. This works by way of the two sets of wheels on each step. The upper set of wheels are connected to the rotating chains, pulled by the gears at the top of the escalator. The lower set of wheels follow behind and just glide along on their track.
Motor - Escalators are driven by a motor and chain system inside the truss. At its core are a pair of chains looped around two pairs of gears. The gears at the top of the escalator are turned by an electric motor, which in turn rotates the chain loops. The electric motor also powers the moving handrail which is looped around a series of wheels and is configured so that it moves at a similar speed to the steps.
Escalators are driven by a motor and chain system inside the truss. At its core are a pair of chains looped around two pairs of gears. The gears at the top of the escalator are turned by an electric motor, which in turn rotates the chain loops. The electric motor also powers the moving handrail which is looped around a series of wheels and is configured so that it moves at a similar speed to the steps.
Lavatory - Wc-1210963 640.jpg
Wc-1210963 640.jpg -
In modern usage, the term lavatory (UK pronunciation: lavah-tree) describes a room or cubicle containing sanitaryware or other receptacles for the passing of human waste. The sanitaryware will usually be connected to a public drainage system.
When used to describe a room, a lavatory may also contain other sanitaryware, such as a bath, shower, urinal or bidet. Other ancillary facilities may typically include wash-hand basins, hot air dryers, towels and mirrors.
The term lavatory is sometimes used synonymously: -
Toilet - WC (although this more correctly refers to the water closet sanitaryware itself)
WC (although this more correctly refers to the water closet sanitaryware itself)
Bathroom (if it contains a bath) - Loo
Loo - Washroom
Washroom - Ladies / gents
Ladies / gents - Sanitary convenience
Sanitary convenience - Powder room
Powder room - Historically, a lavatory was a cistern or trough where the inmates of monastic establishments could wash their hands and faces, as well as their surplices and vestments.
Historically, a lavatory was a cistern or trough where the inmates of monastic establishments could wash their hands and faces, as well as their surplices and vestments.
In southern Germany, lavatories took on grander functions that resembled those of baptistries. They would be either square or octagonal chambers to the side of a cloister and would have a series of water troughs for washing arranged around a fountain located centrally in the room.
The term lavatory was also given to a piscina a drain that was originally connected to Roman aqueducts but which later was applied to a stone basin near a church altar.
Legal requirements for sanitary conveniences, washing facilities and bathrooms are set out in Part G of the building regulations, with solutions to common situations described in Approved Document G (Sanitation, hot water safety and water efficiency).
NB The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, defines a toilet: an enclosed part of a storey which contains a watercloset, a waterless closet or a urinal, which are properly installed for use.
Models in the construction industry - BIM-databook.png
BIM-databook.png -
In very general terms, a model is a representation, often three-dimensional, of a structure system or procedure. It can represent something that already exists, or may be a model that it is intended will be adopted or followed.
A building, such as an architectural model is a type of model (often to scale) built to develop or represent aspects of a design or to communicate design ideas. Historically, such models have been physical representations, made from materials such as paper, cardboard, timber, and so on. These can be used to help explain proposals to clients, planning officers, members of the public and other stakeholders, or they can be used as tools to help designers explore complicated three-dimensional aspects of a design.
More recently, models have been created digitally using software such as computer aided design (CAD) and building information modelling (BIM). 3D printing of digital models is used for a physical representation of digital design files.
Model-based design is a process that involves creating digital representations systems to help with design development and decision-making. It allows rapid analysis and comparison of design alternatives, co-ordination of and collaboration between team members, clear communication and visualisation of information, easy alteration, clash avoidance, and so on.
In the early stages of a project, a digital model might simply include existing information, such as 3D context models, site surveys, condition surveys, information about existing utilities and so on. During the design stages it becomes more detailed, and ultimately, as contractors take over development of the model from designers, it may become a virtual construction model (VCM), containing information allowing all the objects in the model to be manufactured, installed or constructed.
Parametric modelling (or parametric design) is the creation of a digital model based on a series of pre-programmed rules or algorithms known as 'parameters'. That is, the model, or elements of it are generated automatically by internal logic arguments rather than by being manually manipulated. For example, a rule might be created to ensure that walls must start at floor level and reach the underside of the ceiling. Then if the floor to ceiling height is changed, the walls will automatically adjust to suit.
Digital models are generally made up of a number of different component models that may be produced by different consultants, contractors or suppliers.
Ancillary area - An ancillary area of a building is an area that supports the function/s of the primary areas, that is, it is not part of the primary purpose of the building, but is required in order that the primary purpose can function.
An ancillary area of a building is an area that supports the function/s of the primary areas, that is, it is not part of the primary purpose of the building, but is required in order that the primary purpose can function.
Examples of ancillary areas include: -
Plant rooms. - Cleaners rooms.
Cleaners rooms. - ICT rooms.
ICT rooms. - Building services rooms.
Building services rooms. - Storage rooms.
Storage rooms. - Circulation spaces.
Circulation spaces. - In shared buildings, an ancillary area might support more than one occupant, e.g. a shared kitchen, meeting spaces, utility areas, and so on.
In shared buildings, an ancillary area might support more than one occupant, e.g. a shared kitchen, meeting spaces, utility areas, and so on.
In residential buildings, ancillary areas include spaces which do not form part of the main dwelling directly, but nonetheless add some useful value, e.g. patio area, office, garage, conservatory, porch, utility room, and so on.
Patio - According to the International Property Measurement Standards (IPMS): Residential Buildings, published by the International Property Measurement Standards Coalition (IPMSC) in September 2016, a patio is
According to the International Property Measurement Standards (IPMS): Residential Buildings, published by the International Property Measurement Standards Coalition (IPMSC) in September 2016, a patio is
A paved or floored terrace, adjacent to a building, which may or may not be covered by an independent framework.
A veranda is an open or partly enclosed area on the outside of a building at ground level (level 0), and covered by a roof that is an integral part of the building.
Classification systems - Classification systems are lists of things which relate to the same subject. A classification system may be based around an organised structure which can become progressively more granular as it breaks down into further subsets.
Classification systems are lists of things which relate to the same subject. A classification system may be based around an organised structure which can become progressively more granular as it breaks down into further subsets.
Ref Information management according to BS EN ISO 19650 Guidance Part 1: Concepts, second edition, published by the UK BIM Alliance, the Centre for Digital Built Britain and the British Standards Institute in July 2019.
OmniClass - Classification, an introduction describes classification as, what things are called, and how those names are arranged and structured, or the act or process of dividing things into groups according to their type.
Classification, an introduction describes classification as, what things are called, and how those names are arranged and structured, or the act or process of dividing things into groups according to their type.
In the construction industry, classification is used in:
Specifications. - Production information.
Production information. - Libraries.
Libraries. - Drawings.
Drawings. - Schedules of rates / quantities.
Schedules of rates / quantities. - Information management systems.
Information management systems. - Operation and maintenance information.
Operation and maintenance information. - The OmniClass Construction Classification System, also known as OmniClass or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
The OmniClass Construction Classification System, also known as OmniClass or OCCS, is a classification system used for the organising and retrieving of information for the construction industry. It is the North American equivalent of Uniclass.
It covers the full facility lifecycle from conception to demolition or reuse, and all types of construction in the built environment. It is useful for Building Information Modelling (BIM), organising reports and object libraries.
Similar to Uniclass, OmniClass is derived from internationally-accepted standards developed by the International Organisation for Standardisation (ISO) and the International Construction Information Society (ICIS) and has been developed from the early-1990s to the present.
OmniClass comprises 15 tables, some of which focus on buildings and landscapes, and some of which also serve civil and/or process engineering. Each table can be used independently to classify a particular type of information, or entries on it can be combined with entries on other tables to classify more complex subjects.
The tables are as follows: -
Construction Entities by Function Table 11. - Construction Entities by Form Table 12.
Construction Entities by Form Table 12. - Spaces by Function Table 13.
Spaces by Function Table 13. - Spaces by Form Table 14.
Spaces by Form Table 14. - Elements (includes Designed Elements) Table 21.
Elements (includes Designed Elements) Table 21.
Work Results Table 22. - Products Table 23.
Products Table 23. - Phases Table 31.
Phases Table 31. - Services Table 32.
Services Table 32. - Disciplines Table 33.
Disciplines Table 33. - Organisational Roles Table 34.
Organisational Roles Table 34. - Tools Table 35.
Tools Table 35. - Information Table 36.
Information Table 36. - Materials Table 41.
Materials Table 41. - Properties Table 49.
Properties Table 49. - OmniClass incorporates other extant systems currently in use, such as; MasterFormat for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
OmniClass incorporates other extant systems currently in use, such as; MasterFormat for work results, UniFormat for elements, and Electronic Product Information Cooperation (EPIC) for structuring products.
Hydraulic pressure - The term hydraulic pressure refers to: The pressure exerted by water (whether at rest or moving) on a surface or structure. Hydraulic pressure has the units of force per unit area and is calculated for water at rest as the product of the depth of water and its density. The pressure can differ for water in motion. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
The term hydraulic pressure refers to: The pressure exerted by water (whether at rest or moving) on a surface or structure. Hydraulic pressure has the units of force per unit area and is calculated for water at rest as the product of the depth of water and its density. The pressure can differ for water in motion. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
Hydraulic pressure can also refer to the pressure exerted by other liquids, such as those used in mechanical equipment sometimes referred to as hydraulic fluids.
Sound exposure level - Sound exposure level is the sound level at a receptor which, if maintained at a constant level for a period of one second, would have the same amount of energy as a given event (of any duration) at the same receptor.
Sound exposure level is the sound level at a receptor which, if maintained at a constant level for a period of one second, would have the same amount of energy as a given event (of any duration) at the same receptor.
The sound power level (Lw) of a source is a measurement of the total acoustic power it radiates. The sound power level is an intrinsic characteristic of a source (analogous to its volume or mass), which is not affected by the environment within which the source is located.
Sound pressure level is the parameter by which sound levels are measured in air. It is measured in decibels. The threshold of hearing has been set at 0dB, while the threshold of pain is approximately 120dB. Normal speech is approximately 60dB at a distance of 1 metre and a change of 3dB in a time varying sound signal is commonly regarded as being just detectable. A change of 10dB is subjectively twice, or half, as loud. (See also Equivalent continuous sound pressure level)
Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
Privacy in the built environment - Private-1647769 640.jpg
Private-1647769 640.jpg -
In very general terms, privacy refers to the ability to remain unobserved or undisturbed, or to control access to personal information.
In the built environment, privacy typically refers to issues such as visual or speech privacy, that is the ability not to be observed or heard. This is an abstract, context specific and personal concept. For example, a person may feel the need for less privacy on a beach than they do in their home. Here there maybe a distinction between public space or social space and private space. There may be boundaries between these types of spaces, such as doors, walls, fences and so on.
The term personal space refers to the physical space surrounding a person, within which, encroachment by others can make them feel uncomfortable, or even threatened. The extent of this space can vary by person or by situation.
Some aspects of privacy may be fixed, for example the location of a room next to a public entrance, whilst other aspects can be changed, for example by locking a door or closing curtains. In addition, technology now means that whilst we may be within a physical space that could be considered private we can simultaneously be in a digital environment that is public.
Buildings and other spaces may provide layers or zones of privacy. So, for example, spaces that have less need for privacy may be located near an entrance, facing onto a street, or at ground level, whereas spaces requiring more privacy may be placed higher up or in a more secluded location. There may be a range of different degrees of privacy in spaces between the two extremes.
Robinson defined a gradient of privacy: -
Public. - Semi-public.
Semi-public. - Semi private.
Semi private. - Private.
Private. - Semi-intimate.
Semi-intimate. - Intimate.
Intimate. - [Ref Julia W. Robinson, 2001, Institutional Space, Domestic Space, and Power Relations: Revisiting territoriality with space syntax, University of Minnesota, Proceedings . 3rd International Space Syntax Symposium Atlanta.]
[Ref Julia W. Robinson, 2001, Institutional Space, Domestic Space, and Power Relations: Revisiting territoriality with space syntax, University of Minnesota, Proceedings . 3rd International Space Syntax Symposium Atlanta.]
The need for privacy can conflict with requirements for access, security, safety and so on. For example, there may be a conflict in schools where there can be both a need for private spaces, and also a need for supervision and safeguarding. In some situations, privacy may be equated to secrecy, and there is an increasing trend in public architecture to create transparent buildings as evidence that an organisation has nothing to hide.
Some aspects of privacy may be beyond the control of a single development. For example a new building may be constructed that overlooks an existing property, compromising its privacy.
Privacy increasingly relates to the right of individuals to control access to, or retention of, information about them. The General Data Protection Regulation (GDPR) introduced in 2018 was designed to harmonise data privacy laws across Europe, to protect and empower all EU citizens' data privacy and to reshape the way organisations across the region approach data privacy. GDPR gives the public more say over which organisations have access to their data and what they do with it. For more information see: GDPR.
This has implications for any organisations that collect information about people, whether online, or in the built environment, for example in relation to mailing lists, signing in processes, CCTV recordings, smart buildings, the internet of things and so on.
Hydrostatic pressure - The term hydrostatic pressure refers to: The pressure exerted by water at rest. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
The term hydrostatic pressure refers to: The pressure exerted by water at rest. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
Region - Map on hands.jpg
Map on hands.jpg -
In general, a region is defined as being an area of land that has common features and characteristics, and is a concept that is useful for describing spatial areas. Regions are often referred to as being the basic units of geography.
Regions are normally categorised as physical (natural or artificial geographical features), human (language, government, religion, and so on), or environmental (forests, nature, climate, and so on).
Regions are not necessarily defined by boundaries; geographic regions and sub-regions are typically defined by imprecise boundaries that can sometimes be transitory. However, in human geography, regions are typically defined by areas of jurisdiction such as national, county or city borders.
Regions are often expressed as being part of the spatial hierarchy; global, national, regional, local. The regions of England are commonly considered to comprise; South East, London, North West, East of England, West Midlands, South West, Yorkshire and the Humber, East Midlands, North East.
However, regions can also be used to define multi-national global areas, such as; Africa, Asia, Central America, Eastern Europe and so on.
Devolution is the granting of powers away from central government to a sub-national level, such as regional or local, enabling the creation of legislation specific to that particular area. It is a form of decentralisation that provides territories with greater autonomy and independent responsibility. For more information, see Devolution.
In a built environment, regions can be referred to in relation to masterplanning or devising policy for urban regeneration or development. A strategic masterplan might identify how an entire region could be regenerated or changed in order to meet a perceived challenge. For more information, see Masterplanning.
Climate change adaption - The National Planning Policy Framework (NPPF) defines climate change adaption as:
The National Planning Policy Framework (NPPF) defines climate change adaption as:
'Adjustments to natural or human systems in response to actual or expected climatic factors or their effects, including from changes in rainfall and rising temperatures, which moderate harm or exploit beneficial opportunities.'
It defines climate change mitigation as: -
'Action to reduce the impact of human activity on the climate system, primarily through reducing greenhouse gas emissions.'
Duration - An activity is an operation or process consuming time and possibly other resources. An individual or work team can manage an activity. It is a measurable element of a programme.
An activity is an operation or process consuming time and possibly other resources. An individual or work team can manage an activity. It is a measurable element of a programme.
The term duration refers to the length of time needed to complete an activity. The time period can be determined inductively, by determining the start and finish date of an activity or deductively by calculation from the time necessary to expend the resources applied to the activity.
Ref Society of Construction Law Delay and Disruption Protocol, 2nd edition, February 2017, published by the Society of Construction Law (UK). https://www.scl.org.uk/resources/delay-disruption-protocol
Fixtures in buildings - Boiler.jpg Fridge-158792 1280 landscape.png
Boiler.jpg Fridge-158792 1280 landscape.png - According to HMRC, a fixture is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land in law (for example, a boiler).
According to HMRC, a fixture is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land in law (for example, a boiler).
This is as opposed to a chattel, which is, an asset, which is tangible and moveable (such as furniture). For example, a bath may be a fixture, but a fridge a chattel.
HMRC suggest that, a chattel may become a fixture if it is fixed to a building or land. For example, before it is installed in a building as part of a central heating system, a central heating radiator is a chattel. Once installed, it becomes a fixture.
This can be particularly important in the sale of property or in leasehold agreements, where the distinction between fixtures and chattels can determine ownership.
There are two key tests for identifying whether something is a fixture or a chattel:
The degree of physical affixation. This is not a conclusive test, but generally, the greater the degree of affixation (i.e. the damage that would be caused by removal), the more likely it is that an object is a fixture. The easier it is to remove, the more likely it is to be a chattel.
More conclusively, if the object is intended to be permanent and effect a lasting improvement to the property, it is a fixture. However, if any attachment is intended to be temporary and no more than is necessary for the object to be used and enjoyed, then it is a chattel.
However, these tests are not always used as the basis for determining the right to remove an object. Leasehold agreements will generally distinguish between the landlords fixtures and tenants fixtures which they may remove at the end of the lease (as long as they make good any damage). Similarly, conveyancing reports for the sale of property may state that certain fixtures are not being sold as part of the land.
Disputes can arise in particular in relation to expensive items such as paintings that may to a greater or lesser extent be a part of the building in which they are housed. Where there is doubt, it may be advisable to seek legal advice, and ensure that the position is set out in writing before signing any agreement.
In addition, the distinction between fixtures and chattels is important when calculating stamp duty land tax. Fixtures form part of the taxable value of the purchase, whereas chattels do not. The inclusion of fixtures can move the saleable price for tax purposes to the next stamp duty threshold, resulting in a much larger tax liability for the purchaser than had been expected. (Ref. HMRC, SDLTM04010 - Scope: How much is chargeable: Fixtures and fittings.)
HMRC suggest that: -
The following items are, however, confirmed as being assets that will normally be regarded as chattels:
Carpets (fitted or otherwise). - Curtains and blinds.
Curtains and blinds. - Free standing furniture.
Free standing furniture. - Kitchen white goods.
Kitchen white goods. - Electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property).
Electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property).
Light shades and fittings (unless recessed).
On the other hand, the following items will not normally be regarded as chattels:
Fitted kitchen units, cupboards and sinks. - Aga and wall-mounted ovens.
Aga and wall-mounted ovens. - Fitted bathroom sanitary ware.
Fitted bathroom sanitary ware. - Central heating systems.
Central heating systems. - Intruder alarm systems.
Intruder alarm systems. - Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
A deduction would, however, be appropriate for amounts properly apportioned to any plants growing in pots or containers.
Chattel - According to HMRC, a chattel is an asset, which is tangible and moveable (such as furniture). This is as opposed to a fixture, which is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land... (such as a boiler). For example, a bath may be a fixture, but a fridge a chattel.
According to HMRC, a chattel is an asset, which is tangible and moveable (such as furniture). This is as opposed to a fixture, which is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land... (such as a boiler). For example, a bath may be a fixture, but a fridge a chattel.
HMRC suggest that a chattel may become a fixture if it is fixed to a building or land. For example, before it is installed in a building as part of a central heating system, a central heating radiator is a chattel. Once installed, it becomes a fixture.
This can be particularly important in the sale of property or in leasehold agreements, where the distinction between fixtures and chattels can determine ownership.
There are two key tests for identifying whether something is a fixture or a chattel:
The degree of physical affixation. This is not a conclusive test, but generally, the greater the degree of affixation (ie the damage that would be caused by removal) the more likely it is that an object is a fixture. The easier it is to remove, the more likely it is to be a chattel.
More conclusively, if the object is intended to be permanent and effect a lasting improvement to the property, it is a fixture. However, if any attachment is intended to be temporary and no more than is necessary for the object to be used and enjoyed, then it is a chattel.
However, these tests are not always used as the basis for determining the right to remove an object. Leasehold agreements will generally distinguish between the landlords fixtures and tenants fixtures which they may remove at the end of the lease (as long as they make good any damage). Similarly, conveyancing reports for the sale of property may state that certain fixtures are not being sold as part of the land.
Disputes can arise in particular in relation to expensive items such as paintings that may to a greater or lesser extent be a part of the building in which they are housed. Where there is doubt, it may be advisable to seek legal advice, and ensure that the position is set out in writing before signing any agreement.
In addition, the distinction between fixtures and chattels is important when calculating stamp duty land tax. Fixtures form part of the taxable value of the purchase, whereas chattels do not. The inclusion of fixtures can move the saleable price for tax purposes to the next stamp duty threshold, resulting in a much larger tax liability for the purchaser than had been expected.
(Ref. HMRC, SDLTM04010 - Scope: How much is chargeable: Fixtures and fittings.)
HMRC suggest that: -
The following items are, however, confirmed as being assets that will normally be regarded as chattels
carpets (fitted or otherwise) - curtains and blinds
curtains and blinds - free standing furniture
free standing furniture - kitchen white goods
kitchen white goods - electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property)
electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property)
light shades and fittings (unless recessed).
On the other hand, the following items will not normally be regarded as chattels
fitted kitchen units, cupboards and sinks - agas and wall mounted ovens
agas and wall mounted ovens - fitted bathroom sanitary ware
fitted bathroom sanitary ware - central heating systems
central heating systems - intruder alarm systems.
intruder alarm systems. - Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
A deduction would, however, be appropriate for amounts properly apportioned to any plants growing in pots or containers.
Radiator - Radiator.jpg
Radiator.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of radiator
2 Types of radiator - 2.1 Panel radiator
2.1 Panel radiator - 2.2 Convector radiator
2.2 Convector radiator - 2.3 Column radiator
2.3 Column radiator - 2.4 LST radiator
2.4 LST radiator - 2.5 Skirting board radiator
2.5 Skirting board radiator - 3 Bleeding a radiator
3 Bleeding a radiator - 4 Related articles on Designing Buildings Wiki
4 Related articles on Designing Buildings Wiki - Introduction
Introduction - Radiators are heat exchanging devices and are one of the oldest and most effective ways of heating buildings. Typically, they consist of hollow metal panels through which hot water is pumped. Convector fins may be welded to the panels to increase their effective surface area, allowing more air to come into contact with the metal.
Radiators are heat exchanging devices and are one of the oldest and most effective ways of heating buildings. Typically, they consist of hollow metal panels through which hot water is pumped. Convector fins may be welded to the panels to increase their effective surface area, allowing more air to come into contact with the metal.
According to British Standards, radiators should be placed on external walls, wherever possible under windows. This is because mounting is easier on external walls and these are usually the coldest parts of a room.
Radiators use the heat from hot water or sometimes steam to warm the surrounding air. The advantage of using steam is that it can flow through pipes under its own pressure without needing pumps. This is useful for large and tall buildings, however, steam is less efficient due to the higher temperatures at which steam systems operate.
Water hammer is a banging sound that can be made by steam pipes and radiators. It is due to some of the steam condensing into water in a horizontal section of the steam piping and pushing the water at high velocity into a pipe fitting.
Types of radiator - Panel radiator
Panel radiator - These can be either single or double panels without convector fins, and now largely outdated. The panel refers to the long metal containers that run parallel to the wall. The longer the panel, the larger the heat-emitting surface area, so bigger radiators will emit more heat. A double panel radiator will emit more heat than a single panel radiator of the same length.
These can be either single or double panels without convector fins, and now largely outdated. The panel refers to the long metal containers that run parallel to the wall. The longer the panel, the larger the heat-emitting surface area, so bigger radiators will emit more heat. A double panel radiator will emit more heat than a single panel radiator of the same length.
Convector radiator - These are similar to panel radiators but have convector fins welded to them. The three different types are:
These are similar to panel radiators but have convector fins welded to them. The three different types are:
Single panel single convector: One front steel panel and one convector fin.
Double panel single convector: Two steel panels (front and back) and one convector fin.
Double panel double convector: Two steel panels (front and back) and two convector fins.
Round top radiators allow the convector fins to be seen, whereas compact radiators include a grill across the top of the panels to obscure the view of the fins (see top image).
Column radiator - Columnradiator.jpg
Columnradiator.jpg -
Column radiators are made up of steel tubular columns welded to end pieces at the top and bottom. Column radiators can range from single to four columns in depth. Column radiators are popular for their more traditional appearance.
LST radiator - Lstradiator.jpg
Lstradiator.jpg -
An LST radiator has an efficient internal heat emitter in a robust steel enclosure to ensure safety and concealment of pipework and valves. This type of radiator is often found in places where safety concerns are important, such as hospitals, nurseries, schools, care homes, and so on. They do not have sharp corners and maintain a low, safe-to-touch surface temperature, while at the same time delivering the required heat output.
Skirting board radiator - This type of radiator is placed inside a skirting board, saving the wall space. Hot water is piped through the system from the central heating system.
This type of radiator is placed inside a skirting board, saving the wall space. Hot water is piped through the system from the central heating system.
Bleeding a radiator - Bleeding a radiator involves venting air that can build up over time, preventing proper operation of the radiator.
Bleeding a radiator involves venting air that can build up over time, preventing proper operation of the radiator.
Radiators should be bled regularly to ensure the efficiency of the central heating system. It is possible to check whether bleeding is necessary by checking for cool spots, especially near the top of the radiator. Bleeding can be done using a bleeding key or flat-heated screwdriver to open a valve at one end of the radiator. This allows the release of the trapped air until liquid starts to escape, at which point the valve should be quickly closed.
Bleeding radiators may reduce the pressure of the central heating system to below its recommended level. Typically, a filling loop within the boiler can be used to re-pressurise the system.
Timber frame - The term 'timber frame' typically describes a system of panelised structural walls and floors constructed from small section timber studs, clad with board products, in which the timber frame transmits vertical and horizontal loads to the foundations. It is generally not used to refer to timber post and beam structures or to timber engineered structural frames.
The term 'timber frame' typically describes a system of panelised structural walls and floors constructed from small section timber studs, clad with board products, in which the timber frame transmits vertical and horizontal loads to the foundations. It is generally not used to refer to timber post and beam structures or to timber engineered structural frames.
Timber frames can be the most suitable choice if the structural shell is required quickly, if the ground conditions are particularly poor, or if the design does not include very large structural spans. For more information, see Advantages and disadvantages of timber frame buildings
There are a number of ways developing timber frame structures:
A commonly-used method for constructing timber frames is the platform frame, in which each storey is formed by floor-to-ceiling timber panels and a floor deck which then becomes the platform for constructing the next storey.
The engineered stud method with the installation of insulation between the load-bearing timber studs.
The twin stud method involves two timber frame stud walls, positioned parallel to one another, (sometimes with only one carrying the vertical load), with an insulated cavity separating them.
Structural insulated panels (SIPs) take the form of an insulating core sandwiched between two structural facings. In the UK, the mainstream suppliers typically use the same structural facing oriented strand board (OSB). For more information see Structural insulated panels.
Cross-laminated timber (CLT) building systems. See Cross-laminated timber for more information.
Fire resistance can be enhanced by internal linings, such as plasterboard, and cavity barriers which prevent fire from entering the cavity. For more information, see Timber framed buildings and fire.
Timber elements can also be oversized to aid fire resistance. For more information, see Sacrificial timber.
Stud - Timberwall.jpg
Timberwall.jpg -
A stud is a vertical framing member which forms part of a wall or partition. Also known as wall studs, they are a fundamental component of frame construction and are typically made of timber. However, steel studs are increasingly popular, particularly for non load-bearing walls and firewalls.
Studs may carry vertical structural loads, or as part of a partition wall, may be non load-bearing. They are typically sandwiched between top and bottom plates and equally spaced. The spacings will be governed by the size and spanning ability of the facing or cladding material.
Load-bearing walls typically use a double top plate. A single top plate may sometimes be used if the rafters, trusses or joists bearing down on it are directly over the studs.
Traditionally, studs were fastened to the plates by hammer and nail, and then by nail gun. Modern techniques such as screw fasteners, clips and ties can be used to enhance resistance to wind and seismic activity.
Timber studs are easy to use, lightweight, adaptable, and can be clad and infilled with a variety of materials to give different finishes and properties. They should be of prepared or planed material to ensure that the wall is of constant thickness with parallel faces. Care must be taken to ensure that timber studs are completely dry when installed, otherwise they may be prone to shrinking and twisting as they dry out. To ensure they do not become damp, they should be stored carefully on site before usage.
Studs an also hold in place windows, doors, insulation, interior finish, utilities, and so on. In order to form interior and exterior corners, intersecting walls, headers, jambs and sills, studs can be bundled together.
There are different names for studs used to frame window and door openings. These include:
King stud: On either side of a window or door, running from the bottom to top plate.
Trimmer or jack: On either side of a window or door, running from the bottom plate to the underside of a lintel or header.
Cripple stud: Either above or below a framed opening.
Post or column: Group of studs fastened side-by-side.
Cladding for buildings - Cladding.jpg
Cladding.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Types of cladding
2 Types of cladding - 2.1 Curtain walling
2.1 Curtain walling - 2.2 Sandwich panels
2.2 Sandwich panels - 2.3 Patent glazing
2.3 Patent glazing - 2.4 Rainscreen
2.4 Rainscreen - 2.5 Timber cladding
2.5 Timber cladding - 2.6 Metal profile cladding
2.6 Metal profile cladding - 2.7 Tensile fabric coverings
2.7 Tensile fabric coverings - 2.8 Brick slips
2.8 Brick slips - 2.9 Tile hanging
2.9 Tile hanging - 2.10 Shakes and shingle
2.10 Shakes and shingle - 2.11 uPVC
2.11 uPVC - 3 Related articles on Designing Buildings Wiki
3 Related articles on Designing Buildings Wiki - 4 External references
4 External references - Introduction
Introduction - The term 'cladding' refers to components that are attached to the primary structure of a building to form non-structural, external surfaces. This is as opposed to buildings in which the external surfaces are formed by structural elements, such as masonry walls, or applied surfaces such as render.
The term 'cladding' refers to components that are attached to the primary structure of a building to form non-structural, external surfaces. This is as opposed to buildings in which the external surfaces are formed by structural elements, such as masonry walls, or applied surfaces such as render.
Building Safety Fund for the remediation of non-ACM Cladding Systems (England only) Registration prospectus, published by MHCLG in May 2020 suggests that: 'A cladding system includes the components that are attached to the primary structure of a building to form a non-structural external surface. The cladding system includes the weather-exposed outer layer or screen, fillers. Insulation, membranes, brackets, cavity barriers, flashing, fixings, gaskets and sealants.'
Whilst cladding is generally attached to the structure of the building, it typically does not contribute to its stability. However, cladding does play a structural role, transferring wind loads, impact loads, snow loads and its own self-weight back to the structural framework.
In particular, wind causes positive and negative pressure on the surface of buildings and cladding must have sufficient strength and stiffness to resist this load, both in terms of the type of cladding selected and its connections back to the structure.
Cladding is needed to: -
Create a controlled internal environment. - Protect the building from external conditions.
Protect the building from external conditions. - Provide privacy and security.
Provide privacy and security. - Prevent the transmission of sound.
Prevent the transmission of sound. - Provide thermal insulation.
Provide thermal insulation. - Create an external facade.
Create an external facade. - Prevent the spread of fire.
Prevent the spread of fire. - Generate an 'airtight' building envelope.
Generate an 'airtight' building envelope. - Providing openings for access, daylight and ventilation.
Providing openings for access, daylight and ventilation.
Cladding is often prefabricated in panels that are attached to the structural frame of the building, and some cladding systems can be purchased 'off the shelf'.
Cladding systems may include additional components, such as windows, doors, gutters, roof lights, vents and so on.
The nature of cladding selected for a particular building will depend on considerations such as:
How the building is going to be used.
Internal and external conditions. - Durability.
Durability. - Local context.
Local context. - Planning requirements.
Planning requirements. - Building regulations requirements.
Building regulations requirements. - Accessibility and buildability.
Accessibility and buildability. - Appearance.
Appearance. - Availability.
Availability. - Budget.
Budget. - Maintenance requirements.
Maintenance requirements. - Structural requirements.
Structural requirements. - High-quality, well-designed, properly-installed cladding can help maximise thermal performance, minimise air leakage, and optimise natural daylighting. This can help reduce the need for mechanical and electrical building services, and so improve energy efficiency and lower capital and running costs.
High-quality, well-designed, properly-installed cladding can help maximise thermal performance, minimise air leakage, and optimise natural daylighting. This can help reduce the need for mechanical and electrical building services, and so improve energy efficiency and lower capital and running costs.
Poor design detailing or installation may compromise cladding performance and can result in safety problems such as cladding collapse or cladding panels pulling away from the structure.
When selecting or designing a suitable cladding, designers should pay particular attention to:
Design detailing. - Control of air leakage.
Control of air leakage. - Control of condensation.
Control of condensation. - Integrity and continuity of Insulation.
Integrity and continuity of Insulation. - Prevention of water penetration, or provision of drainage.
Prevention of water penetration, or provision of drainage.
Control of thermal movement. - Spread of fire.
Spread of fire. - Ease of installation.
Ease of installation. - External attachments and fixings.
External attachments and fixings. - Cleaning.
Cleaning. - Maintenance, remedial work and renewal.
Maintenance, remedial work and renewal. - Resilience, strength and durability.
Resilience, strength and durability. - Types of cladding
Types of cladding - The NBS Building libraries categorise claddings and coverings as:
The NBS Building libraries categorise claddings and coverings as:
H10 Patent glazing - H11 Curtain walling
H11 Curtain walling - H13 Structural glass assemblies
H13 Structural glass assemblies - H14 Precast concrete and glass lens / paver rooflights / floor lights / pavement lights / security panels
H14 Precast concrete and glass lens / paver rooflights / floor lights / pavement lights / security panels
H20 Rigid sheet cladding - H21 Timber weatherboarding
H21 Timber weatherboarding - H22 Plastics weatherboarding
H22 Plastics weatherboarding - H30 Fibre cement profiled sheet cladding / covering
H30 Fibre cement profiled sheet cladding / covering - H31 Metal profiled / flat sheet cladding / covering
H31 Metal profiled / flat sheet cladding / covering
H32 Plastics profiled sheet cladding / covering - H40 Glass fibre reinforced concrete panel cladding / components
H40 Glass fibre reinforced concrete panel cladding / components
H41 Glass fibre reinforced plastics cladding / features - H42 Precast concrete panel cladding / features
H42 Precast concrete panel cladding / features - H43 Metal composite panel cladding / features
H43 Metal composite panel cladding / features - H51 Natural stone slab cladding / lining / features
H51 Natural stone slab cladding / lining / features
H60 Plain roof tiling - H61 Fibre cement slating
H61 Fibre cement slating - H62 Natural slating
H62 Natural slating - H64 Wood shingle and shake roofing
H64 Wood shingle and shake roofing - H65 Single lap roof tiling
H65 Single lap roof tiling - H67 Metal single lap roof tiling
H67 Metal single lap roof tiling - H71 Lead sheet coverings / flashings
H71 Lead sheet coverings / flashings - H72 Aluminium strip / sheet coverings / flashings
H72 Aluminium strip / sheet coverings / flashings - H73 Copper strip / sheet coverings / flashings
H73 Copper strip / sheet coverings / flashings - H74 Zinc strip / sheet coverings / flashings
H74 Zinc strip / sheet coverings / flashings - H75 Stainless steel strip / sheet coverings / flashings
H75 Stainless steel strip / sheet coverings / flashings
H90 Tensile fabric coverings - H91 Thatch roofing
H91 Thatch roofing - H92 Rainscreen cladding
H92 Rainscreen cladding - Some of the more common types of cladding are described below.
Some of the more common types of cladding are described below.
Curtain walling - Curtain wall systems are a non-structural cladding system for the external walls of buildings. They are generally associated with large, multi-storey buildings. Typically curtain wall systems comprise a lightweight aluminium frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as 'glazing' whether or not they are made of glass.
Curtain wall systems are a non-structural cladding system for the external walls of buildings. They are generally associated with large, multi-storey buildings. Typically curtain wall systems comprise a lightweight aluminium frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as 'glazing' whether or not they are made of glass.
See Curtain wall systems for more information. -
Sandwich panels - Sandwich panels (sometimes referred to as composite panels or structural insulating panels (SIP)) consist of two layers of a rigid material bonded to either side of a lightweight core, so that the three components act as a composite.
Sandwich panels (sometimes referred to as composite panels or structural insulating panels (SIP)) consist of two layers of a rigid material bonded to either side of a lightweight core, so that the three components act as a composite.
See Sandwich panel and Metal composite panels for more information.
Patent glazing - The term patent glazing refers to a non-load bearing, two-edge support cladding system. Patent glazing bars provide continuous support along two edges of glazing infill panels (rather than four-edge curtain walling), and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
The term patent glazing refers to a non-load bearing, two-edge support cladding system. Patent glazing bars provide continuous support along two edges of glazing infill panels (rather than four-edge curtain walling), and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
See Patent glazing for more information. -
Rainscreen - A rainscreen (sometimes referred to as a drained and ventilated or pressure-equalised faade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
A rainscreen (sometimes referred to as a drained and ventilated or pressure-equalised faade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
See Rainscreen for more information. -
Timber cladding - One of the most popular methods of cladding is through the use of timber softwoods, such as western red cedar. This type of wood is relatively knot-free and has a natural resistance to decay and moisture. It can be readily stained or painted and altered to create a range of profiles.
One of the most popular methods of cladding is through the use of timber softwoods, such as western red cedar. This type of wood is relatively knot-free and has a natural resistance to decay and moisture. It can be readily stained or painted and altered to create a range of profiles.
Hardwoods can also be used including oak and sweet chestnut. Both of which contain high tannin levels which can result in leaching and streaking after exposure to the elements. Thermally modified timbers are also being used such as Kebony, Keywood, Platowood and ThermoWood. These softwoods are heated to high temperatures which removes moisture and resins, resulting in a stable and durable material.
See Timber cladding for more information. -
Metal profile cladding - Sheets are manufactured in a range of corrugated and other profiles, such as trapezoidal, sinusoidal or half-round. The profiles are manufactured from sheets fed through banks of forming rollers.
Sheets are manufactured in a range of corrugated and other profiles, such as trapezoidal, sinusoidal or half-round. The profiles are manufactured from sheets fed through banks of forming rollers.
See Metal profile cladding for more information. -
Tensile fabric coverings - A fabric membrane is 'stretched' to form a three-dimensional surface that may be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some materials.
A fabric membrane is 'stretched' to form a three-dimensional surface that may be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some materials.
See Fabric structures for more information. -
Brick slips - Brick slips are thin layers of masonry and are of similar appearance to conventional bricks. They are available in a variety of styles and colours.
Brick slips are thin layers of masonry and are of similar appearance to conventional bricks. They are available in a variety of styles and colours.
See Bricks for more information. -
Tile hanging - The traditional method of cladding a property is through the use of tiles. The addition of which can add character to older properties.
The traditional method of cladding a property is through the use of tiles. The addition of which can add character to older properties.
Shakes and shingle - Shakes and shingles are produced from split logs and look similar to timber tiles. Shakes are typically split from the log using a chisel and mallet whilst shingles are sawn off.
Shakes and shingles are produced from split logs and look similar to timber tiles. Shakes are typically split from the log using a chisel and mallet whilst shingles are sawn off.
For more information, see Shingle roofing. -
uPVC - One of the cheaper forms of cladding is uPVC with white being the cheapest option. It can have fewer detailing requirements than timber and requires less maintenance, although it can discolour with age.
One of the cheaper forms of cladding is uPVC with white being the cheapest option. It can have fewer detailing requirements than timber and requires less maintenance, although it can discolour with age.
Durability - Naturalstone1.jpg
Naturalstone1.jpg - Durability is the resistance to degradation of products, materials, buildings and other built assets over time. This can be a difficult property to assess - whilst a tough material may be hard to the touch but it may also be non-durable if it decomposes or is eroded in a relatively short period of time.The opposite can also be true.
Durability is the resistance to degradation of products, materials, buildings and other built assets over time. This can be a difficult property to assess - whilst a tough material may be hard to the touch but it may also be non-durable if it decomposes or is eroded in a relatively short period of time.The opposite can also be true.
Many factors affect durability, whether concerning the nature of the material itself or the way it has been assembled with other materials:
Molecular structure. - Resistance to damp, moisture and water.
Resistance to damp, moisture and water. - Resistance to corrosive substances.
Resistance to corrosive substances. - Resistance to vermin and other aggressive animal life such as wood boring beetles.
Resistance to vermin and other aggressive animal life such as wood boring beetles.
Resistance to mould and rot. - Fire resistance.
Fire resistance. - Ability to accept movement.
Ability to accept movement. - Resistance to atmospheric pollution.
Resistance to atmospheric pollution. - Resistance to heat and cold.
Resistance to heat and cold. - Capacity for moisture absorption.
Capacity for moisture absorption. - Surface profiles, orientation, texture and colour.
Surface profiles, orientation, texture and colour.
As well as its constituent materials, a building as a complete entity may also be said to be durable (or non-durable). Buildings constructed for temporary purposes, such as demountable site cabins and exhibition pavilions, do not tend to stand the test of time because they are not designed to.
A building will be subjected not only to daily wear and tear from users but also to the constant influence of climate in particular rain, frost, sun and heat forces collectively referred to as weathering. Such forces can cause significant deterioration and therefore a reduction in durability.
As well as diminishing durability, weathering forces can also result in a change of appearance usually a change for the worse however some materials can be affected beneficially: some stones and brick types for example, as well as some metals such as copper which develop a patina.
As well as causing potential staining particularly in polluted areas some forms of weathering e.g acid rain, result in chemical actions which can cause deterioration of the building fabric. Changes in moisture content, temperature, frost, sunlight, soil and groundwater action, atmospheric pollution and the action of electrolytes, mould and insect attack can lead to corrosion, erosion and disintegration of materials and construction details. Materials must therefore be carefully understood and specified according to their properties, their juxtaposition with other materials in the building and the potential destructive agents they may face.
Design can have a direct effect on durability: even the best materials may deteriorate prematurely if they are not adequately maintained, and a design which makes this difficult e.g timberwork that is inaccessible and so infrequently painted, will have adverse effects on component durability. Sometimes, designers must face a trade-off between the initial costs of materials and the likely future costs of maintenance and the resulting effect on durability.
Economic considerations will play a significant part in determining the durability of a construction: the best possible materials assembled in a considered, careful way tends to be the costliest method of approach yet this may frequently result in best quality and longest durability.
Durability is becoming more of a concern in relation to the likely impact of climate change, in particlular, higher temperatures, rising water levels and more frequent extreme weather events.
In some cases buildings may be designed to be deconstructed, as well as being durable, so that at the end of their lives, they can be easily recycled or re-used.
Paint - Paint.jpg
Paint.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 The constituents of paint
2 The constituents of paint - 3 Types of paint
3 Types of paint - 4 Paint finishes
4 Paint finishes - 4.1 Matte paint
4.1 Matte paint - 4.2 Eggshell and satin
4.2 Eggshell and satin - 4.3 Semi-gloss
4.3 Semi-gloss - 4.4 Gloss
4.4 Gloss - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - 6 External references
6 External references - Introduction
Introduction - Paint is a liquid or mastic material that can be applied to surfaces to colour, protect and provide texture. They are usually stored as a liquid and dry into a thin film after application. Paints be categorised decorative, are applied on site, or industrial, applied in factories as part of the manufacturing process.
Paint is a liquid or mastic material that can be applied to surfaces to colour, protect and provide texture. They are usually stored as a liquid and dry into a thin film after application. Paints be categorised decorative, are applied on site, or industrial, applied in factories as part of the manufacturing process.
Some of the attributes normally required from a paint include:
Capable of easy application. - Good flow out of application marks (e.g. brush-marking).
Good flow out of application marks (e.g. brush-marking).
Capable of forming a continuous protective film. - High opacity.
High opacity. - Quick drying.
Quick drying. - Corrosion resistance.
Corrosion resistance. - Water and heat resistance.
Water and heat resistance. - Colour stability against visible and ultraviolet radiation.
Colour stability against visible and ultraviolet radiation. - Abrasion and scratch resistance.
Abrasion and scratch resistance. - Durability.
Durability. - Flexibility.
Flexibility. - Easily cleaned.
Easily cleaned. - Paints can be applied with a brush or roller, or by dipping, flowcoating, spraying, hot spraying, electrostatic spraying, airless spraying, electrodeposition, powder coating, vacuum impregnation, immersion, and so on.
Paints can be applied with a brush or roller, or by dipping, flowcoating, spraying, hot spraying, electrostatic spraying, airless spraying, electrodeposition, powder coating, vacuum impregnation, immersion, and so on.
The constituents of paint - Paints may be manufactured using pigments, binders, extenders, solvents and additives.
Paints may be manufactured using pigments, binders, extenders, solvents and additives.
The pigments provide the paint with its colour and opacity. Pigments can be made of either organic or inorganic derivatives. The pigment powder is broken down into individual particles which are coated by and dispersed in a binder (resin), in a process known as 'wetting out'.
The binder is a polymer which forms a matrix to hold the pigment in place. The three most commonly-used binders are:
Acrylic polymers. - Alkyd polymers.
Alkyd polymers. - Epoxy polymers.
Epoxy polymers. - An organic solvent is added to achieve the required consistency, improving the application of the paint to reduce its viscosity.
An organic solvent is added to achieve the required consistency, improving the application of the paint to reduce its viscosity.
Extenders may also be added. These larger pigment particles provide improved adhesion and strengthen the film.
Depending on the intended use of the paint, other additives may be used to modify the properties of the liquid paint or dry film:
Driers: For speeding up the drying time.
Silicones: To improve the paints resistance to weather.
Dispersants: To separate and stabilise pigment particles.
Thixotropic agents: These provide paints with a thick consistency.
Anti-settling agents: These are used to prevent the pigment from settling.
Bactericides: These act as a preservative when the paint is in the can.
Fungicides and algaecides: Protect paint films from mould, algae and lichen.
Types of paint - Oil-based paint, also described as enamel, is commonly used for exteriors, timber and metal due to its hardness and durability. It can create a glossy finish to surfaces. Oil-based enamel tends to dry between 8-24 hours depending on ventilation and humidity conditions.
Oil-based paint, also described as enamel, is commonly used for exteriors, timber and metal due to its hardness and durability. It can create a glossy finish to surfaces. Oil-based enamel tends to dry between 8-24 hours depending on ventilation and humidity conditions.
Water-based paint, also described as latex paint or acrylic if the binding ingredient is a form of acrylic, takes less time to dry than oil-based, however, they are less glossy and are often less durable.
Although not strictly paint, primer is often required as a component when working with paint. Oil-based paint will require an oil-based primer, and water-based paint will require a water-based primer.
Very generally, oil-based paints can be applied onto water-based paints, but water-based paints cannot be applied onto oil-based paints.
Paint finishes - Matte paint
Matte paint - The most common interior wall finish is matte, which is easy to apply using a brush or roller, and doesnt provide a distracting shine or sheen to the finish. A solid colour is often achieved through applying more than one single coat. However, matte paint is easily marked and requires regular retouching.
The most common interior wall finish is matte, which is easy to apply using a brush or roller, and doesnt provide a distracting shine or sheen to the finish. A solid colour is often achieved through applying more than one single coat. However, matte paint is easily marked and requires regular retouching.
Eggshell and satin - An eggshell finish has a very subtle shine but without the same smoothness as a satin finish. As they are only partially reflective, they do not highlight imperfections making them suitable as interior wall paint. They are easy to apply and can often cover well with a single coat. They are frequently used in demanding environments such as kitchens and bathrooms, where they provide some water resistance, and can be cleanable.
An eggshell finish has a very subtle shine but without the same smoothness as a satin finish. As they are only partially reflective, they do not highlight imperfections making them suitable as interior wall paint. They are easy to apply and can often cover well with a single coat. They are frequently used in demanding environments such as kitchens and bathrooms, where they provide some water resistance, and can be cleanable.
Semi-gloss - Semi-gloss is more commonly used for trimmings such as baseboards, mouldings and doors rather than walls. It offers a hard finish, is easily cleanable, and is suitable for heavy use. The shine is less than full gloss, but a single coat is usually sufficient for a good covering.
Semi-gloss is more commonly used for trimmings such as baseboards, mouldings and doors rather than walls. It offers a hard finish, is easily cleanable, and is suitable for heavy use. The shine is less than full gloss, but a single coat is usually sufficient for a good covering.
Gloss - This is commonly used on woodwork and metal as it provides a high shine. However, gloss paint tends to show imperfections and often requires several coats.
This is commonly used on woodwork and metal as it provides a high shine. However, gloss paint tends to show imperfections and often requires several coats.
Office - Officepic.jpg
Officepic.jpg -
An office is a building, portion of a building, or a room, that is used for desk-based business purposes.
Approved Document B defines an office as '...premises used for any of the following and their control:
Administration. - Clerical work (including writing, bookkeeping, sorting papers, filing, typing, duplicating, machine calculating, drawing and the editorial preparation of matter for publication, police and fire and rescue service work).
Clerical work (including writing, bookkeeping, sorting papers, filing, typing, duplicating, machine calculating, drawing and the editorial preparation of matter for publication, police and fire and rescue service work).
Handling money (including banking and building society work).
Communications (including postal, telegraph and radio communications).
Radio, television, film, audio or video recording.
Performance (premises not open to the public).
An office can be built in almost any location or building, although requirements in terms of light, access, services, security, flexibility and layout may influence its location and design. Houses and other buildings can be designed with a room dedicated as an office. Alternatively, an office building (or office block), provides purpose-built accommodation for sale or lease for businesses to operate from. The primary purpose of an office building is to provide a healthy, safe, conducive and efficient working environment for its users.
When considering the office space needed, analysis should be carried out of the types of spaces required (i.e. open office spaces, enclosed cubicles, private meeting facilities, conference areas etc), the number of employees (current and anticipated), recreational requirements, welfare facilities, and so on.
For more information, see Office space planning.
An office building will often be divided into sections, or floors, for different organisations, or the whole building can be used by one organisation. Designing the most appropriate office space can be difficult though, since many different people perform many different roles and tasks within an organisation and may have differing requirements or tastes for their workplace. Generally, offices will contain some or all of the following generic types of work space:
Open plan: A floor space that isnt enclosed, typically made up of rows of desks for use by a large number of people.
Team space: A semi-enclosed work space for groups of people.
Cubicle: Semi-enclosed work space for use by one person.
Private office: An enclosed work space for use by one person.
Shared office: An enclosed work space for use by two or more people.
Study booth: An enclosed work space for use by one person for a short period, i.e. for making a phone call or holding a video meeting.
Offices often include meeting spaces, such as:
Meeting rooms: Enclosed meeting spaces. - Meeting spaces: Open or semi-open spaces
Meeting spaces: Open or semi-open spaces - Meeting points: Open spaces suitable for ad hoc and informal meetings.
Meeting points: Open spaces suitable for ad hoc and informal meetings.
Other types of spaces that are often found in an office building include:
Filing space: Space for storage of files and documents for easy access.
Storage space: Open or enclosed space for storing office supplies such as stationary.
Printing area: Open or enclosed space with printers, scanners, copiers, and so on.
Post area: Open or semi-open space for storing and collecting employee mail.
Kitchen/dining area: Open or enclosed space for employees to prepare and eat food adn drinks.
Break area: Space where employees can take a break from work.
Welfare facilities: Such as toilets and locker rooms:
Library: Room for storing and reading books and other documents.
Reception: Open or semi-open space for visitors to register and wait.
Server rooms. For ICT equipment. - On a construction site, office facilities are often needed to provide accommodation for site managers, provide space for meetings and to provide storage for site documentation. Each individual project will have different requirements for site office provision. On large projects separate offices may be provided for site foremen, engineers and the commercial and project management team.
On a construction site, office facilities are often needed to provide accommodation for site managers, provide space for meetings and to provide storage for site documentation. Each individual project will have different requirements for site office provision. On large projects separate offices may be provided for site foremen, engineers and the commercial and project management team.
For more information, see Site office. -
The term office can also be used to refer to government bodies, departments or agencies. For example, Office of Government Property (OGP), Office of Government Commerce (OGC - no longer in existence), Cabinet Office, Home Office, National Audit Office (NAO), and so on.
Designing Buildings Wiki has a range of articles relating to offices, including:
British Council for Offices. - Criteria for the choice of a structural system to be included in office specification.
Criteria for the choice of a structural system to be included in office specification.
Design for deconstruction, office building. - Fit for office use.
Fit for office use. - INSPiRe renovation solutions for residential and office buildings.
INSPiRe renovation solutions for residential and office buildings.
Lifts for office buildings. - London office construction continues to rise.
London office construction continues to rise. - Office definition.
Office definition. - Office manual.
Office manual. - Post Occupancy Evaluation: operational performance of a refurbished office building.
Post Occupancy Evaluation: operational performance of a refurbished office building.
Smart office lighting. - Structural systems for offices.
Structural systems for offices. - The Biophilic Office.
The Biophilic Office. - Workplace definition.
Workplace definition. - NB The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, suggests office means: .a building or premises used for office, administrative or clerical purposes (including writing, book-keeping, sorting papers, filing, typing, duplicating, machine calculating, police and fire service work, drawing and editorial preparation of work for publication), financial transactions (including banking and building society work) and communications (including postal, telegraph and radio, television, film, audio or video recording or performance (not open to the public), communication or control).
NB The Scottish Building Standards, Part I. Technical Handbook Domestic, Appendix A Defined Terms, suggests office means: .a building or premises used for office, administrative or clerical purposes (including writing, book-keeping, sorting papers, filing, typing, duplicating, machine calculating, police and fire service work, drawing and editorial preparation of work for publication), financial transactions (including banking and building society work) and communications (including postal, telegraph and radio, television, film, audio or video recording or performance (not open to the public), communication or control).
Workplace definition - The term workplace refers to a place made available to an employee for the purposes of carrying out work. This includes a wide variety of places, such as offices, factories, farms, shops, and so on, indeed, in the age of digital technology, a workplace can be realistically anywhere with an internet and phone connection.
The term workplace refers to a place made available to an employee for the purposes of carrying out work. This includes a wide variety of places, such as offices, factories, farms, shops, and so on, indeed, in the age of digital technology, a workplace can be realistically anywhere with an internet and phone connection.
A study by the Office for National Statistics in June 2014, found that the UK had 4.2m people who worked from home (13.9% of the working population).
However, despite this, the Workplace (Health, Safety and Welfare) Regulations, define a workplace as:
any premises or part of premises which are not domestic premises and are made available to any person as a place of work, and includes
(a) any place within the premises to which such person has access while at work; and
(b) any room, lobby, corridor, staircase, road or other place used as a means of access to or egress from that place of work or where facilities are provided for use in connection with the place of work other than a public road.
Polymers in construction - A polymer is a substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together. In basic terms, polymers are very long molecules typically made up of many thousands of repeat units.
A polymer is a substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together. In basic terms, polymers are very long molecules typically made up of many thousands of repeat units.
Many synthetic and organic materials are based on polymers, including; plastics, rubbers, thermoplastic elastomers, adhesives, foams, paints and sealants. Polymer materials account for the highest growth area in construction materials. Well-established applications of polymers in construction include products used for flooring, windows, cladding, pipes, membranes, seals, insulation, and so on. With thousands of commercially available polymers new applications are emerging all the time.
However, the introduction of polymeric materials has brought with it new concerns, particularly relating to their longevity, how they are affected by ageing and weathering, the effects of pollution, environmental and sustainability issues, fire performance, re-use, recycling or disposal at their end of life and so on.
Examples of polymer materials in construction include: -
Epoxy resins: Solid resin, Terrazzo flooring, anchor fixings and adhesives.
Ethylenetetrafluoroethylene (ETFE): Fabric structures. - Ethyl vinyl acetate (EVA): Solar panel encapsulants.
Ethyl vinyl acetate (EVA): Solar panel encapsulants.
Expanded polystyrene (EPS): Concrete moulds, insulation and packaging.
Polycarbonate: Lighting housings, fittings in hot water systems and glazing.
Polyester: FRP Bridge sections, cladding panels, sinks, surfaces and coatings.
Polyethylene: Foam underlay, damp-proof membranes and coatings.
Polyisobutylene (PIB): Sealants and waterproof membranes.
Polymethylmethacrylate / Acyrlic (PMMA): Surfaces and sinks.
Polypropylene (PP): Sound insulation, and pipes.
Polyurethane (PU): Sealants and concrete jointing.
Polyvinylchloride (PVC): Sealants, concrete jointing and fabric structures.
Rubber: Bridge bearings and flooring. -
Fabric structures - Fabricstructure.jpg
Fabricstructure.jpg -
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 History
2 History - 3 Materials
3 Materials - 4 Properties and characteristics
4 Properties and characteristics - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - Introduction
Introduction - Fabric structures are tensile structures in which a membrane is 'stretched' to form a three-dimensional surface that can be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some other materials.
Fabric structures are tensile structures in which a membrane is 'stretched' to form a three-dimensional surface that can be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some other materials.
Typically, the membrane is formed by a structural fabric, consisting of a woven base cloth, coated on both sides, and held in position by tension forces imposed by a structural framework or a cabling system. Unlike conventional roofing systems, fabric structures can cover very large areas with no supporting columns. This makes them particularly suitable for buildings such as sports faculties, auditoriums, shopping centres, transport interchanges, and so on.
They can be relatively quick to construct and can be relocatable, making them suitable for temporary uses, and so have historically be associated with structures such as circus tents, or with military uses.
History - The origins of fabric structures can be traced back more than 44,000 years to the ice age and the Siberian Steppe, where remains have been found of simple shelters constructed from animal skins draped between sticks. Fabric structures developed and thrived predominately in regions where materials were scarce, or where survival required mobility; both conditions which tend to be brought about by low rainfall.
The origins of fabric structures can be traced back more than 44,000 years to the ice age and the Siberian Steppe, where remains have been found of simple shelters constructed from animal skins draped between sticks. Fabric structures developed and thrived predominately in regions where materials were scarce, or where survival required mobility; both conditions which tend to be brought about by low rainfall.
From these purely functional origins however, the tent evolved over many centuries to become a symbol of frivolity. Fabric structures became almost entirely recreational, and other than for military purposes were used in ways which ran entirely contrary to their functional origins.
This was to change during the nineteenth and twentieth centuries as architects became inspired by technological breakthroughs in structural engineering and architectural theorising on an emerging functional aesthetic.
The architect, Frei Otto, began exhaustive investigations into the structural principles behind a new generation of fabric buildings, and ultimately, this led to the extraordinary developments we now associate with modern fabric structures such as the roof of the Hajj Terminal at Jeddah Airport, the Millennium Dome and Denver International Airport.
Materials - The earliest fabrics were formed by simple membranes extracted from animals or vegetables. Later these membranes were cut into strips and interlaced to form larger, more practical textiles, and eventually these strips were twisted into circular sections allowing the manufacture of flexible, continuos fibres with enhanced strength.
The earliest fabrics were formed by simple membranes extracted from animals or vegetables. Later these membranes were cut into strips and interlaced to form larger, more practical textiles, and eventually these strips were twisted into circular sections allowing the manufacture of flexible, continuos fibres with enhanced strength.
Cotton was the first material to possess any significant structural strength but modern fabric structures tend to be formed using PVC coated polyester or PTFE coated glass.
Topcoats of protective fluorinated polymer lacquers (PVDF) applied to PVC coated polyester enhance its 'cleanability' and provide additional protection. In average climates, this fabric can last 15-20 years, or around 5 years less in sites where there is high exposure to sunlight.
Architectural fabric.jpg -
PFTE-coated glass cloth is more expensive, but is strong and durable, and can have a lifespan of 30 to 50 years. It also has the advantage of being low maintenance and self-cleaning.
More recently, high performance materials such as silicone coated glass, woven PTFE fibre, ETFE foil, laminated open weave grids and insulated and phase change materials have been developed, however, PVC coated polyester and PTFE coated glass remain the industry standards.
These tensile fabrics, (sometimes referred to as structural membranes or architectural fabrics) are available in a wide range of thicknesses, strengths, colours and translucencies.
For more information see: The development of structural membranes and Architectural fabrics.
Properties and characteristics - Fabric structure.JPG
Fabric structure.JPG -
Fabric structures are generally given their structural stability by double curvature. This may be:
Anticlastic (saddle shaped), where the two axes of the fabric curve in opposite directions.
Synclastic (dome shaped), where the two axis of the fabric curve in the same direction.
Anticlastic shapes tend to be formed by cables at the perimeter of fabric panels pulling them into tension, whilst synclastic shapes tend to be formed by internal air pressure (similar to blowing up a balloon, but at a very low pressure not noticeable to occupants).
Whilst the fabric itself may be very thin (perhaps just 1 mm), the tensile force imposed on it to ensure it remains stable under load can be high, and so the supporting structure required can be significant to transfer loads to the foundations.
The non-linear, dynamic behaviour of architectural fabrics can be modelled using specialist form-finding software. This allows designers to vary the elements, boundary conditions and geometry of the design and rapidly determine the most efficient structural solution. This software can also be used to generate cutting patterns for automatically cutting the fabric panels to create the form required. For more information see: The structural behaviour of architectural fabric structures.
Light shelf - Lightshelf.jpg
Lightshelf.jpg -
A light shelf is a passive architectural device used to reflect natural daylight into a building. 'Bouncing' sunlight off a horizontal surface distributes it more evenly and deeply within a space, whereas direct sunlight can cause glare near an opening, whilst leaving dark areas further in.
Light shelves can be fixed either externally, internally or both (which often works best in providing an even illumination gradient). They are often designed as part of a broader daylight and shading strategy.
They are generally found on walls facing the sun, as on 'pole-facing walls' would tend to act only as sunshades. On east and west orientations, they may act as an effective means of reducing direct heat gain and glare but will not bounce light as deeply into the space.
Exterior light shelves can be more effective than internal light shelves as they do not radiate as much heat into the space and so can help reduce solar heat gain and cooling loads.
Internal light shelves however may be easier to maintain as they can be more accessible and less exposed. In very broad terms, internal light shelves tend to have a depth similar to the height of the opening that they sit below.
Light shelves are commonly made from; timber, glass, plastics, metal panels, plaster, acoustic panels and so on. The choice of material may be determined by considerations regarding the design of the rest of the building, structural strength, ease of maintenance, cost, durability and so on. Opacity is not essential, as some transparency can help more-evenly distribute light.
To be able to reflect light up to the ceiling, the upper surface of light shelves should be matte white or diffusely specular, it does not need to be shiny or reflective. Ideally, the ceiling should also be a light colour.
Light shelves can: -
Enhance daylight quality. - Reduce the need for artificial lighting and so reduce energy consumption.
Reduce the need for artificial lighting and so reduce energy consumption.
Reduce cooling loads. - Increase occupant comfort and productivity.
Increase occupant comfort and productivity. - Enhance design aesthetics.
Enhance design aesthetics. - Some of the limitations or drawbacks of light shelves are as follows:
Some of the limitations or drawbacks of light shelves are as follows:
They tend to be best-suited to mild rather than tropical or desert climates.
They can interfere with the installation of sprinkler systems.
They may require a higher floor-to-ceiling height. - Their design must be coordinated with windows.
Their design must be coordinated with windows. - They Increase maintenance requirements.
They Increase maintenance requirements. - Alternative solutions to light shelves include the use of blinds and louvre window systems!
Alternative solutions to light shelves include the use of blinds and louvre window systems!
Light well - A light well (or lightwell) is an architectural feature that can be used to take natural light into the interior spaces of a building. It takes the form of a vertical shaft within the volume of a building that typically penetrates from roof level down to lower levels, allowing the transmission of natural light to areas that would otherwise require artificial lighting. Light wells can also be used to promote ventilation.
A light well (or lightwell) is an architectural feature that can be used to take natural light into the interior spaces of a building. It takes the form of a vertical shaft within the volume of a building that typically penetrates from roof level down to lower levels, allowing the transmission of natural light to areas that would otherwise require artificial lighting. Light wells can also be used to promote ventilation.
Light wells may be open to the elements at the top (i.e. without a roof), with internal windows around its perimeter, or it may be open internally with glazing at the top.
The advantages of light wells are that they can reduce the electric lighting requirements of a building, as well as providing an open space that can be used as an outdoor area or garden.
A large light well may be referred to as an atrium.
Small, highly-reflective light wells that 'collect' light and transmit it to the interior of a building may be referred to as daylight systems or light tubes.
Rooflight - Windows are openings fitted with glass to admit light and allow people to see out. They are often openable to allow ventilation. Rooflights (sometimes described as roof lights or skylights) are windows built into the roof of a building.
Windows are openings fitted with glass to admit light and allow people to see out. They are often openable to allow ventilation. Rooflights (sometimes described as roof lights or skylights) are windows built into the roof of a building.
Approved Document B2, Fire safety: Buildings other than dwellinghouses, defines a rooflight as:
A dome light, lantern light, skylight, ridge light, glazed barrel vault or other element to admit daylight through a roof.
Lantern roof light.jpg Rooflight.JPG - Rooflights are effective at allowing natural light deep into the centre of a building, particularly where it is not possible to install windows in perimeter walls or where privacy is needed. Where they are openable, they can also be effective at promoting natural ventilation, as they tend to be at the top of buildings and so can benefit from the stack effect. They may also be used to allow access to roofs or to roof terraces.
Rooflights are effective at allowing natural light deep into the centre of a building, particularly where it is not possible to install windows in perimeter walls or where privacy is needed. Where they are openable, they can also be effective at promoting natural ventilation, as they tend to be at the top of buildings and so can benefit from the stack effect. They may also be used to allow access to roofs or to roof terraces.
Some rooflights however can be seen as a poor design solution, contributing little to the architectural form of a building, and simply creating a hole in a roof because without them there would be insufficient natural light. They can also suffer from ponding, dirt accumulation and staining.
Rooflights must have safety glazing, and if they are out of reach, may need a mechanism or motor to open them.
In some areas, some rooflights may be considered a permitted developments, not requiring planning permission. However, it is sensible to consult with the local planning authority to check this.
BS EN 14351-1 (Windows and doors. Product standard, performance characteristics. Windows and external pedestrian doorsets) suggests that the term roof window refers to a window that is in the same plane as the surrounding roof, and has a minimum pitch of 15 degrees. This is as opposed to 'rooflights' which by this definition are installed on an upstand, and so are not in the same plane as the surrounding roof.
Terraced house - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 1.1 Small terraced house
1.1 Small terraced house - 1.2 Medium/large terraced house
1.2 Medium/large terraced house - 1.3 End terraced house
1.3 End terraced house - 1.4 Mid terraced house
1.4 Mid terraced house - 2 Related articles on Designing Buildings Wiki
2 Related articles on Designing Buildings Wiki - Introduction
Introduction - According to the Planning (Subterranean Development) Bill [HL] 2015-16, Terraced houses are defined as, 'a row of adjoining buildings where each building has a wall built at the line of juncture between itself and the adjoining property which provides structural support to itself and a building on the adjoining property.'
According to the Planning (Subterranean Development) Bill [HL] 2015-16, Terraced houses are defined as, 'a row of adjoining buildings where each building has a wall built at the line of juncture between itself and the adjoining property which provides structural support to itself and a building on the adjoining property.'
The English Housing Survey Housing Stock Report, 2014-15, prepared by the Department of Communities and Local Government, categorises terraced houses as:
Small terraced house - A house with a total floor area of less than 70 sq. m forming part of a block where at least one house is attached to two or more other houses. The total floor area is measured using the original EHS (English Housing Survey) definition of usable floor area, used in EHS reports up to and including the 2012 reports.
A house with a total floor area of less than 70 sq. m forming part of a block where at least one house is attached to two or more other houses. The total floor area is measured using the original EHS (English Housing Survey) definition of usable floor area, used in EHS reports up to and including the 2012 reports.
That definition tends to yield a smaller floor area compared with the definition that is aligned with the Nationally Described Space Standard and used on the EHS since 2013. As a result of the difference between the two definitions, some small terraced houses are reported in the 2014 Housing Stock Report as having more than 70 sq. m.
Medium/large terraced house - A house with a total floor area of 70 sq. m or more forming part of a block where at least one house is attached to two or more other houses. The total floor area is measured using the original EHS definition of useable floor area which tends to yield a small floor area compared with the definition used on the EHS since 2013.
A house with a total floor area of 70 sq. m or more forming part of a block where at least one house is attached to two or more other houses. The total floor area is measured using the original EHS definition of useable floor area which tends to yield a small floor area compared with the definition used on the EHS since 2013.
End terraced house - A house attached to one other house only in a block where at least one house is attached to two or more other houses.
A house attached to one other house only in a block where at least one house is attached to two or more other houses.
Mid terraced house - A house attached to two other houses in a block.
A house attached to two other houses in a block.
NB Ministry of Housing, Communities and Local Government, Permitted development rights for householders, Technical Guidance, September 2019 defines a terraced house as:
'...a dwellinghouse situated in a row of 3 or more dwellinghouses used or designed for use as single dwellings, where:
(a) it shares a party wall with, or has a main wall adjoining the main wall of, the dwellinghouse on either side or
(b) if it is at the end of a row, it shares a party wall with or has a main wall adjoining the main wall of a dwellinghouse which fulfils the requirements of subparagraph (a).
Louvre (or louver) - Chair and louvre shutters 248293 640.jpg
Chair and louvre shutters 248293 640.jpg -
A louvre (pronounced loover) comprises narrow, sloping slats held in a frame and typically used to cover a vertical opening such as a window or an air vent. They provide screening and can also prevent access, shade from the sun and provide protection against wind and rain.
Louvres can be made of wood, glass and metal particularly aluminium. In a window, the louvres may form part of a shutter (usually timber) applied either inside or outside of the window opening. The latter are very common in hot countries as they can allow air to circulate yet provide a degree of solar shading. They can also afford privacy to those on the inside.
Where the slats of a louvre are adjustable, it is termed a jalousie. A jalousie may form an entire window in which case it may comprise a series of adjustable, horizontal glass slats. In the UK however, it is more common to have a narrow jalousie of three or four louvres adjustable for ventilation above a much larger fixed pane of glass.
Internal louvred wooden shutters have become popular in the UK as they can form attractive architectural elements in their own right; they may incorporate adjustable slats, give excellent screening and provide an attractive alternative to the ubiquitous net curtain. they can also act as a light shelf, reflecting sunlight deep into a building's interior.
Aluminium louvred panels are sometimes fixed externally to building facades to reduce glare to the building occupants. Freestanding louvred screens may also be used to mask unsightly areas, such refuse storage areas, mechanical plant and so on.
Double glazing - Double-glazed.jpg
Double-glazed.jpg -
The term 'glazing' refers to the glass component of a building's faade or internal surfaces.
Historically, the external windows of buildings were generally single glazed, consisting of just one layer of glass, however, a substantial amount of heat is lost through single glazing, and it also transmits a significant amount of noise, so mulit-layerd glazing systems were developed such as double glazing and triple glazing.
Double glazing comprises two layers of glass separated by a spacer bar (also known as a profile); a continuous hollow frame typically made of aluminium or a low heat-conductive material. The spacer bar is bonded to the panes using a primary and secondary seal which creates an airtight cavity, typically with 6-20 mm between the two layers of glass. This space is filled with air or with a gas such as argon, which improves the thermal properties of the window. Larger cavities may be provided to achieve greater sound reduction.
A desiccant in the spacer bar absorbs any residual moisture within the cavity, preventing internal misting as a result of condensation.
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a buildings fabric are as insulators. That is, how effective they are at preventing heat from transmitting between the inside and the outside of a building. Typically, the U-value of single glazing is around 4.8 to 5.8 W/mK, whilst double glazing is around 1.2 to 3.7 W/mK. NB Triple can achieve a U-value below 1 W/mK.
Thermal performance is affected by the quality of the installation, the inclusion of thermal breaks in the frame, suitable weather seals, the gas used to fill the units, and the type of glass used. Low-e glass has a coating added to one or more of its surfaces to reduce its emissivity so that it reflects, rather than absorbs, a higher proportion of long-wave infra-red radiation..
The sound reduction achieved by single glazing (6 mm thick) is typically around 27 dB, whilst double glazing (100 mm air space) is around 42 dB.
The sound reduction achieved by double glazing is affected by:
Good installation to ensure airtightness - Sound absorbent linings to the reveals within the air space.
Sound absorbent linings to the reveals within the air space.
The weight of glass used the heavier the glass, the better the sound insulation.
The size of air space between layers - up to 300 mm.
Low-e glass - The term low-e glass is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity.
The term low-e glass is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity.
Emissivity is an indicator of the amount of long-wave infra-red radiation which a surface (such as the faade of a building) will emit to its surroundings. According to Kirchoff's law the emissivity of a surface is equal to its radiant absorptivity at a given temperature and wavelength. It is expressed as a proportion of 1, so if a surface absorbs 40% of the long-wave infra-red radiation incident on its surface, it has an emissivity of 0.4.
All bodies which are hotter than 0K emit thermal radiation and absorb thermal radiation. In general, the higher the temperature of a body, the lower the average wavelength of the radiation it emits. The range of terrestrial temperatures experienced within the built environment is comparatively cold compared to the sun and so they are radiating at a much longer wavelength. This anomaly allows us to distinguish between short-wave solar radiation and long-wave infra-red radiation (terrestrial radiation).
Typically, glass is relatively transparent to short-wave solar radiation, but opaque to long-wave infra-red radiation. This is said to produce a greenhouse effect, where solar radiation enters a space, and heats it up, but the resulting long-wave infra-red radiation emitted by the hot internal surfaces is unable to escape.
However, glass has a relatively high emissivity. This means that although it does not transmit long-wave infra-red radiation incident on its surface, it does absorb it. This absorbed heat is then re-radiated.
Low-e coatings can be used to reduce the effective emissivity of the surface of glass so that it reflects, rather than absorbs, a higher proportion of long-wave infra-red radiation.
In cooler climates this means that long-wave infra-red radiation that builds up inside a building is reflected by the glass back into the space, rather than being absorbed by the glass and then partially re-radiated to the outside. This reduces heat loss and so the need for artificial heating.
In hotter climates, a low-e coating means that long-wave infra-red radiation outside the building is reflected back out of the building, rather than being absorbed by the glass and then partially re-radiated to the inside. This reduces the heat build-up inside the building and so the need for cooling. In hotter climates, a low-e coating might be used in conjunction with solar-control glass to reduce the amount of short-wave solar radiation entering the building.
Low-e coatings can reduce the emissivity of glazing from more than 0.8 to 0.2 or even as low as 0.04. Coatings tend to be either hard pyrolytic coatings which are applied to molten glass, or soft sputtered coatings, which generally need to be protected within the sealed unit.
Operational costs for built assets - Operational costs are cost incurred in the day-to-day operation of an organisation (sometimes referred to as revenue account expenditure).
Operational costs are cost incurred in the day-to-day operation of an organisation (sometimes referred to as revenue account expenditure).
Operational costs might include: -
Wages. - Utilities.
Utilities. - Maintenance and repairs.
Maintenance and repairs. - Rent.
Rent. - Sales.
Sales. - General and administrative expenses.
General and administrative expenses. - It is important to distinguish between operational costs and capital costs as there are significant accounting and taxation issues which stem directly from how a particular item of expenditure is treated. It can affect whether a particular transaction is subject to capital gains tax as opposed to income tax, as well as the possible entitlement to capital allowances, and, of course, there is the matter of how such treatment affects profitability.
It is important to distinguish between operational costs and capital costs as there are significant accounting and taxation issues which stem directly from how a particular item of expenditure is treated. It can affect whether a particular transaction is subject to capital gains tax as opposed to income tax, as well as the possible entitlement to capital allowances, and, of course, there is the matter of how such treatment affects profitability.
Whilst operational costs are cost incurred in the day-to-day operation of an organisation, capital costs are costs associated with one-off expenditure on the acquisition, construction or enhancement of significant fixed assets including land, buildings and equipment that will be of use or benefit for more than one financial year.
Whilst it is generally relatively straight forward to identify expenditure to acquire or construct fixed assets, distinguishing between enhancements and operational costs such as repairs, maintenance, or replacement can be difficult. Very broadly, enhancements should either:
Significantly lengthen the life of the asset. - Significantly increase the value of the asset.
Significantly increase the value of the asset. - Significantly increase usefulness of the asset.
Significantly increase usefulness of the asset. - The capital cost of developments can include:
The capital cost of developments can include: -
Land or property acquisition. - Commissions.
Commissions. - Statutory fees.
Statutory fees. - Consultant fees directly associated with the development.
Consultant fees directly associated with the development. - Materials, plant and equipment.
Materials, plant and equipment. - Labour.
Labour. - Fixtures and fittings.
Fixtures and fittings. - Project insurance, inflation, taxation and financing.
Project insurance, inflation, taxation and financing.
Internal costs directly associated with the development. - In a commercial setting, accounting practice permits certain items of expenditure, which may appear to be operational in nature, to be capitalised. Furthermore a company's profitability can be enhanced or degraded according to how some items of expenditure are treated.
In a commercial setting, accounting practice permits certain items of expenditure, which may appear to be operational in nature, to be capitalised. Furthermore a company's profitability can be enhanced or degraded according to how some items of expenditure are treated.
On a new development It is common practice to capitalise many items, such as consultants fees, which, on the face of it, would appear to be short term in nature. This is permitted under accountancy rules as such fees are an integral part of the development budget and so may be included in the total capital cost of a scheme. By treating such fees as an asset and placing their value onto the balance sheet, a company is enhancing its profitability as these fees would otherwise have to be set against the income of the company in question.
NB Capital allowances are tax deductible amounts which relate to specific categories of expenditure, most typically plant and equipment, and fixtures and fittings. By definition not all capital expenditure qualifies for capital allowances, for example, consultants fees or Land Duty Stamp Tax.
In construction, capital costs and operational costs can be considered to be associated with separate, distinct stages, with capital costs during acquisition and construction, and then a 'handover' to operational costs when the client takes possession of the completed development.
Capital costs and operational costs can be seen as competing needs, with higher capital costs often resulting in lower operational costs, as a higher quality asset may have lower maintenance and repair costs, lower utilities costs, and so on. Whilst sometimes the division between capital and operational costs can be one of necessity, based on the resources available to the client at the time, it can be a calculated decision based on assessment of whole-life costs.
Whole life costs consider all costs associated with the life of a building including:
Acquisition. - Fees
Fees - Construction.
Construction. - Insurance, inflation and financing.
Insurance, inflation and financing. - Fixtures, fittings and equipment.
Fixtures, fittings and equipment. - Relocation.
Relocation. - Operation.
Operation. - Disposal.
Disposal. - Whilst it is often tempting to seek savings in the early stages of a project, the relative benefit of this tends to be outweighed by the long-term impact.
Whilst it is often tempting to seek savings in the early stages of a project, the relative benefit of this tends to be outweighed by the long-term impact.
This is sometimes demonstrated by the following rough assessment of the typical costs of an office building over 30 years in the ratio:
0.1 to 0.15 for design costs (ref OGC Achieving Excellence Guide 7 - Whole-Life costing).
1 for construction costs. - 5 for maintenance and building operating costs during the lifetime of the building.
5 for maintenance and building operating costs during the lifetime of the building.
200 for the cost of operating the business during the lifetime of the building.
Ref. Report of the Royal Academy of Engineering on The long term costs of owning and using buildings (1998).
However, this has been criticised as misleading, not least because the construction industry accounts for around 7% of GDP, implying a much more significant proportion of business costs than the ratio suggests. Other ratios of construction costs to operational costs to business costs have suggested figures as low as 1:0.6:6 for some types of buildings. However, the usefulness of these ratios is questionable, other than if they are calculated based on actual figures for specific businesses.
Capital costs for construction projects - Capital costs are costs associated with one-off expenditure on the acquisition, construction or enhancement of significant fixed assets including land, buildings and equipment that will be of use or benefit for more than one financial year.
Capital costs are costs associated with one-off expenditure on the acquisition, construction or enhancement of significant fixed assets including land, buildings and equipment that will be of use or benefit for more than one financial year.
Whilst it is generally relatively straight forward to identify expenditure to acquire or construct fixed assets, distinguishing between enhancements and 'revenue account' expenditure (sometimes called revenue expenditure or operational costs) such as repairs, maintenance, or replacement can be difficult.
Very broadly, capital enhancements should either: -
Significantly lengthen the life of the asset. - Significantly increase the value of the asset.
Significantly increase the value of the asset. - Significantly increase usefulness of the asset.
Significantly increase usefulness of the asset. - It is important to distinguish between capital and revenue account costs as there are significant accounting and taxation issues which stem directly from how a particular item of expenditure is treated. On a personal level, it can affect whether a particular transaction is subject to capital gains tax as opposed to income tax. In a commercial environment similar issues arise, as well as the possible entitlement to capital allowances, and how such treatment affects profitability.
It is important to distinguish between capital and revenue account costs as there are significant accounting and taxation issues which stem directly from how a particular item of expenditure is treated. On a personal level, it can affect whether a particular transaction is subject to capital gains tax as opposed to income tax. In a commercial environment similar issues arise, as well as the possible entitlement to capital allowances, and how such treatment affects profitability.
The capital cost of developments can include: -
Land or property acquisition. - Commissions.
Commissions. - Statutory fees.
Statutory fees. - Consultant fees directly associated with the development.
Consultant fees directly associated with the development. - Materials, plant and equipment.
Materials, plant and equipment. - Labour.
Labour. - Fixtures and fittings.
Fixtures and fittings. - Project insurance, inflation, taxation and financing.
Project insurance, inflation, taxation and financing.
Internal costs directly associated with the development. - Operational costs incurred in day-to-day operations might include:
Operational costs incurred in day-to-day operations might include:
Wages. - Utilities.
Utilities. - Maintenance and repairs.
Maintenance and repairs. - Rent.
Rent. - Sales.
Sales. - General and administrative expenses.
General and administrative expenses. - In a commercial setting, accounting practice permits certain items of expenditure, which may appear to be operational in nature, to be capitalised, and a company's profitability can be enhanced or degraded according to how some items of expenditure are treated.
In a commercial setting, accounting practice permits certain items of expenditure, which may appear to be operational in nature, to be capitalised, and a company's profitability can be enhanced or degraded according to how some items of expenditure are treated.
In construction and property these are complex issues, with additional complexity arising where a project may involve a combination of new build and repair and refurbishment.
On a new development it is common practice to capitalise items, such as consultants fees, which, on the face of it, would appear to be short term in nature. This is permitted under accountancy rules as such fees are an integral part of the development budget and so they may be included in the total capital cost of a scheme. By treating such fees as an 'asset' and including their value on the balance sheet, a company is enhancing its profitability as these fees would otherwise have to be set against the income of the company in question.
Capital allowances are tax deductible amounts which relate to specific categories of expenditure, most typically plant and equipment, and fixtures and fittings. By definition not all capital expenditure qualifies for capital allowances for example, consultants fees or Stamp Duty Land Tax.
Approved document F, Ventilation, defines airtightness as a general descriptive term for the resistance of the building envelope to infiltration with ventilators closed. The greater the airtightness at a given pressure difference across the envelope, the lower the infiltration.
It suggests that air permeability is the physical property used to measure the airtightness of the building fabric. It is defined as air leakage rate per hour per square metre of envelope area at a test reference pressure differential across the building envelope of 50 Pascal (50N/m2). The design air permeability is the target value set at the design stage.
In April 2002 the UK government introduced legislation to enforce standards of building air tightness. This was intended to lower running costs; verify the standards of materials, components and workmanship; prevent uncomfortable drafts and avoid condensation problems.
This is achieved by air permeability testing (air tightness, air infiltration or blower door testing), which measures the air leakage rate per hour per square metre of building envelope area at a test reference pressure differential across the building envelope of 50 Pascal (50 N/m2).
Generally, this involves mounting a door, incorporating a fan, into the frame of an external door opening. The fan is used to depressurise the building by extracting air, and the resulting difference between the external and internal pressure can be used to calculate the permeability of the building envelope (given that the area of envelope is known). This permeability is an indicator of how well sealed the building is, and whether there are openings in the envelope. Testing requires that fires are put out, doors and windows are closed and ventilators are shut or sealed.
The method for testing required by the building regulations is set out in ATTMA TSL1 (for dwellings) and ATTMA TSL2 (for non-dwellings).
ATTMA is the Air Tightness Testing & Measurement Association. ATTMA was authorised on behalf of the government to create the testing standards.
The regulations set a limiting air permeability of 10 m-3.h-1.m-2@50Pa (metres cubed, per hour, per metre squared of external building envelope area) and require that the Building Emission Rate (BER, or Dwelling Emission Rate (DER) for dwellings) calculated using the assessed air permeability does not exceed the Target Emission Rate (TER).
The design air permeability is the target value used to calculate the TER. The assessed air permeability is the measured value used to establish the BER (or DER).
Testing is required on all residential developments (this may be a sample of units) and non-dwellings. Buildings with a useful floor area less than 500m2 MAY be exempt. Where testing is not carried out, an assessed air permeability of 15m3/h.m2 must be used in calculations.
On large developments, where a specific dwelling is not tested, the assessed air permeability is the average test result obtained from other dwellings of the same dwelling type on the development, increased by 2.0m3/h.m2.
In compartmentalised buildings where pressure testing the whole unit may be impractical, testing may be carried out on a representative area.
Air permeability testing can be carried out as an isolated study, or may be provided as part of a complete service to demonstrate Part L compliance (including Standard Assessment Procedure (SAP) calculations and Energy Performance Certificates (EPCs)) or may be part of an overall energy audit. Ideally, it should not be carried out simply as a compliance test, but should include an assessment of details, and diagnostic tests such as infrared thermography and if necessary smoke tests, to pinpoint air leakage paths.
Electrical energy is the term given to energy that has been converted from electric potential energy. This electric potential energy has usually been in turn converted from another source of energy, through a process known as generation.
Electrical energy is supplied by a voltage (or electrical potential) delivered via an electric current.
Electrical power is defined as the rate at which electrical energy is transferred via an electrical circuit over a given amount of time. It is therefore the rate of doing work. The SI unit of electrical power is the watt, which equates to an energy transfer rate of 1 joule per second.
In the context of buildings, electrical energy is typically converted into other forms of energy, to serve useful purposes such as heating, lighting, motion or other forms of electrical power conversion.
Electrical energy for use in buildings is often supplied via a grid connection, and typically originates at a power station, where it has been generated by electro-mechanical generators. Electrical energy can by generated by many means, such as chemical combustion, nuclear fission, or renewable means such as flowing water, wind, geothermal heat and solar voltaic.
Equally, electrical energy may be generated at the building itself, typically either via solar voltaic, localised electromechanical generators or other renewable sources. Such energy may be used locally within the building or may be exported back into the grid for use by other consumers. Where this latter facility exists, the building and its system are referred to as a prosumer i.e. a simultaneous producer and consumer of electrical energy.
Geothermal - The term geothermal refers to: Heat derived within the sub-surface of the earth. Water and/or steam carry the geothermal energy to the Earths surface. Depending on its characteristics, geothermal energy can be used for heating and cooling purposes or be harnessed to generate clean electricity.
The term geothermal refers to: Heat derived within the sub-surface of the earth. Water and/or steam carry the geothermal energy to the Earths surface. Depending on its characteristics, geothermal energy can be used for heating and cooling purposes or be harnessed to generate clean electricity.
Ref Climate Emergency Design Guide: How new buildings can meet UK climate change targets, published by the London Energy Transformation Initiative (LETI) in January 2020.
Heat pump - Heat pumps transfer heat from a lower temperature source to one of a higher temperature. This is the opposite of the natural flow of heat.
Heat pumps transfer heat from a lower temperature source to one of a higher temperature. This is the opposite of the natural flow of heat.
A refrigerant fluid is run through the lower temperature source. The fluid absorbs heat and boils, even at temperatures below 0C (although the coefficient of performance (COP) decreases with lower temperature). The resulting gas is then compressed, which further increases its temperature. The gas is passed into heat exchanger coils, where it condenses, releasing its latent heat. The process then repeats.
This is the same process that is used to extract heat from a fridge.
Heat pumps can be used domestically or commercially to provide hot water, space heating (either by providing hot water for under-floor heating or radiators, or supplying hot air) or other applications such as heating swimming pools.
In the UK, heat pumps are most commonly air-source or ground-source heat pumps. However, the temperature of ground water sources in the UK tends to be fairly constant for most of the year, at between 8 and 12C, and so water source heat pumps can be more efficient.
Air source heat pumps absorb heat from the outside air. Air-to-water systems provide hot water for direct use or to supply radiators or underfloor heating systems. Air-to-air systems provide hot air, either directly into an internal space, or to be distributed by fans throughout a building. See Air source heat pumps for more information.
Ground source heat pumps use lengths of plastic pipe buried in the ground, either in a borehole or a horizontal trench. See Air source heat pumps for more information.
Water source heat pumps absorb heat from a suitable local water source, such as a lake, river, well, borehole and so on. They can be open-loop or closed-loop systems. See Air source heat pumps for more information.
Heat pumps may be eligible for payments under the governments Renewable Heat Incentive (RHI) scheme. Domestic schemes may also be eligible for financing through the green deal, however, there has been very poor uptake of the Green Deal, and it is generally considered that better financial deals are available elsewhere.
Refrigeration units also use heat pumps, as do chiller units that provide chilled water (CHW) for space cooling, for example in air handling units, fan coil units, chilled beams and so on. In this case, the system is reversed, absorbing heat from the interior and releasing it to the outside.
Reversible heat pumps can operate in either heating or cooling mode, using a reversing valve to change the direction of flow.
Heat pumps generally use electricity to power the compressor. However, in absorption heat pumps, the refrigerant (typically ammonia) is absorbed into water, then is released again by being heated. The heat source is generally gas fuelled (Gas Absorption Heat Pumps GAHP) but other heat sources can be used, such as solar heated water.
NB The Energy White Paper, Powering our Net Zero Future (CP 337), published in December 2020 by HM Government, defines a heat pump as: A device that extracts heat from the air, ground or water and concentrates it to a higher temperature and delivers it elsewhere, for example to a central heating system. It can replace traditional fossil fuel heating, such as a gas or oil boiler. Heat pump systems are designed to extract a greater amount of heat energy from the surrounding environment than the energy they consume in doing so, therefore they can act as a more efficient source of heat than a conventional electric heater, producing two to three times (or more for very efficient systems) as much heat output as they consume in electricity input.
Biogas - Biogas is formed by anaerobic digestion, that is, the microbial degradation of organic material such as farm wastes or energy crops. This process is sometimes referred to as biomethanation.
Biogas is formed by anaerobic digestion, that is, the microbial degradation of organic material such as farm wastes or energy crops. This process is sometimes referred to as biomethanation.
Biogas is mainly composed of methane and carbon dioxide, but may also contain small amounts of nitrogen, hydrogen and carbon monoxide, as well water vapour and contaminants such as hydrogen sulphide and siloxanes.
After a relatively striaght-forward clean-up process, biogas (sometimes called biomethane or renewable natural gas (RNG)) can be used as a fuel. Biogas has been used as a fuel for many centuries, and in the UK, the city of Exeter used biogas for street lighting as early as 1895.
The production of biogas not only provides a renewable source of energy, it also offers a use for waste products that might otherwise be difficult to dispose of.
The waste products from biogas generation iteslf are water and fermented organic material which can be used as a high-quality fertiliser.
Typically, anaerobic digestion requires a heat source, and so biogas is often used to fuel combined heat and power (CHP) plant that produces both electricity and heat. The heat can be used for the anaerobic digestion process and can also be used to pasteurise animal-derived waste so that it can be used as fertilisers.
Combined heat and power plant can feed electricity into the national grid, and so biogas installations may qualify for payments under the renewable heat incentive (RHI) scheme (other than biogas from landfill).
Biogas can also be cleaned of carbon dioxide and fed into the national grid.
NB -
Net Zero by 2050, A Roadmap for the Global Energy Sector, published by the International Energy Agency in May 2021, defines biogas as: A mixture of methane, carbon dioxide and small quantities of other gases produced by anaerobic digestion of organic matter in an oxygen-free environment.
Is suggests that biogases: Include biogas and biomethane.
Introduction - Deconstruction has been defined as construction in reverse. As construction involves assembling and erecting buildings, so deconstruction is the complete opposite: it involves taking buildings apart piece by piece, avoiding damage by extracting carefully what is required. This contrasts with demolition which tends to be a relatively arbitrary and destructive process, although generally quicker. Falling materials, noise, nuisance and dust often accompany conventional demolitions, not to mention large amounts of waste.
Deconstruction has been defined as construction in reverse. As construction involves assembling and erecting buildings, so deconstruction is the complete opposite: it involves taking buildings apart piece by piece, avoiding damage by extracting carefully what is required. This contrasts with demolition which tends to be a relatively arbitrary and destructive process, although generally quicker. Falling materials, noise, nuisance and dust often accompany conventional demolitions, not to mention large amounts of waste.
A building may be deconstructed if it is located in a sensitive area and its demolition would involve danger to the immediate vicinity, or if it has been designed for deconstruction so that its parts can be re-used or recycled.
Benefits - Deconstruction offers the following benefits compared to demolition:
Deconstruction offers the following benefits compared to demolition:
Lowers the requirement for extracting virgin resources. - Can be a cleaner, more environmentally-friendly process with less pollution released into the atmosphere and into water courses.
Can be a cleaner, more environmentally-friendly process with less pollution released into the atmosphere and into water courses.
Can result in less embodied energy compared to a totally new building.
Saves energy due to fewer loads transported to site.
Allows materials to be reused or recycled and so contributes to the circular economy.
Offers controlled waste management. - Reused materials from deconstruction can offer a different aesthetic to newly manufactured materials.
Reused materials from deconstruction can offer a different aesthetic to newly manufactured materials.
Deconstruction activities tend to be more labour intensive therefore they can provide more jobs locally.
Less material goes to landfill. - Why deconstruct?
Why deconstruct? - Deconstruction allows the reuse of materials, which is more environmentally friendly and results in less waste going to landfill this is critical as construction and demolition waste can comprise up to 20% of all solid waste that ends up in landfills. In addition, some materials may have become more valuable at the time of deconstruction than they were during the original construction, such as some types of brick, decorative cast iron and so on.
Deconstruction allows the reuse of materials, which is more environmentally friendly and results in less waste going to landfill this is critical as construction and demolition waste can comprise up to 20% of all solid waste that ends up in landfills. In addition, some materials may have become more valuable at the time of deconstruction than they were during the original construction, such as some types of brick, decorative cast iron and so on.
When materials are reused/recycled, the resulting building can have less embodied energy and so a smaller carbon footprint. Designing for deconstruction (DfD) requires that designers focus on sustainability, durability and lifecycle analysis, especially when choosing materials and ensuring that the construction process does not render future deconstruction an impractical process. High quality materials integrated into a construction that is as simple as possible can be effective as well as avoiding the use of techniques that rely on nailing and adhesives.
Deconstruction may also keep alive traditional building crafts, such as the use of lime mortars and stone dressings. Furthermore, it can provide opportunities for trainees and apprentices to learn how buildings are put together and to gain skills, such as in basic carpentry, critical thinking and teamwork.
However, not all materials can be salvaged for reuse. Of these, some can be recycled on- or off-site otherwise they may have to be taken to landfill, while hazardous materials, such as asbestos and lead paint, require expert disposal.
Deconstruction tends to be a labour-intensive process given its selective nature. It can take weeks to harvest materials from a structure, whereas demolition can be completed in as little as a day.
A typical deconstruction process involves first removing windows, doors, appliances and finishes from the structure, much of which may be reused or resold. Then the structure is dismantled, usually from the roof, through the middle floors, down to the foundations.
DfD design principles - Ten common principles of design for deconstruction are:
Ten common principles of design for deconstruction are:
Design for prefabrication, pre-assembly and modular construction: prefabricated units are generally easily deconstructed and can be transported in large units. Additionally, modular construction materials allow for large quantities to be transported in one journey.
Simplify and standardise connection details: this allows for efficient construction and deconstruction and reduces the need for multiple tools.
Simplify and separate building systems: separating out the distribution systems within non-structural walls can allow for selective removal of low-value components. Consolidating plumbing services will also reduce the lengths of pipe required.
Consideration of worker safety: the design should aim to reduce potential hazards and the use of potentially hazardous materials.
Minimise building parts and materials: the design should aim to minimise the number of building materials and the equipment required.
Select fittings, fasteners, adhesives, sealants etc that allow for disassembly.
Design to allow for deconstruction logistics: small design tweaks can allow for significant improvements in waste-removal efficiency.
Reduce building complexity: this will reduce costs and improve buildability as well as simplifying the deconstruction process.
Design with reusable materials: consideration of materials that are adaptable and will be useful in the future. Materials such as wood, steel members, brick and carpet tiles may be reused or refurbished.
Design for flexibility and adaptability: the design should consider any future renovations or adaptations that may be required to extend the life of the building.
Timber - Timber lends itself to easier reuse than say, brick, stone or metal. The benefits of avoiding timber waste mean fewer disposal costs, a reduction in greenhouse gas emissions (methane) from decomposition. The process typically has a 33% efficiency rate: it is estimated that every three square-feet of deconstructed timber will yield around one square foot of new timber construction.
Timber lends itself to easier reuse than say, brick, stone or metal. The benefits of avoiding timber waste mean fewer disposal costs, a reduction in greenhouse gas emissions (methane) from decomposition. The process typically has a 33% efficiency rate: it is estimated that every three square-feet of deconstructed timber will yield around one square foot of new timber construction.
Cradle-to-grave is: A boundary condition associated with embodied carbon, carbon footprint and LCA (Life Cycle Assessment) studies. It includes the cradle to site results but also includes the GHG (Greenhouse Gas) emissions associated with the in use of the material or product (maintenance) and the end of life (disposal, reuse, recycling).
Cradle-to-cradle: Goes beyond cradle to grave and conforms more to the model of the circular economy. In a cradle to cradle model products would be designed in a way so that at the end of their initial life they can be readily reused, or recycled, and therefore avoid landfill altogether.
The latest buzz words in the market are 'circular economy'. Given the phenomenal rise of circular economy thinking in recent years, the waste hierarchy as it stands may no longer be a valid starting point for business.
'Business as usual' sees contractors and the supply chain following the waste hierarchy; reduce, reuse and recycle, to a greater or lesser extent. But the concept of the circular economy goes beyond the 3 R's and aims to maximise total material resource efficiency.
The traditional 'linear' model preaches the concept of 'make, break, and discard'. The circular economy is a concept in which everything is engineered to be constantly reused or recycled. It requires rethinking of design, manufacturing, selling, re-using, recycling and consumer ownership to keep resources in use for as long as possible and to extract maximum value.
There is massive economic advantage for businesses adopting a circular economy. The Department for Environment, Food and Rural Affairs (Defra) calculates profit of up to 23 billion per year for UK businesses through low cost or no cost improvements and McKinsey estimates a global value of $3.7 trillion per year (ref. WRAP).
The Dutch are hot favourites in the race to becoming a circular economy and Japan has already shown a huge success in changing their linear manufacturing and consumption system into a more circular, collaborative system. The approach adopted by Japan is highly effective and contributes a significant proportion of the country's GDP, employing hundreds of thousands of people.
As the EU set new, challenging waste targets and reviews proposals to ban sending plastics, wood, textiles and food to landfill, the circular economy may be the answer to our resource and employment challenges.
Definition - Circular Building Assessment is an assessment approach and method that aims to provide a holistic evaluation and interpretation of multiple sustainability aspects of buildings and their parts.
Circular Building Assessment is an assessment approach and method that aims to provide a holistic evaluation and interpretation of multiple sustainability aspects of buildings and their parts.
Taking a life cycle approach, aspects that are included are the environmental impact, financial costs, health consequences and social value of the object under study. Developed within the BAMB-project, Circular Building Assessment fosters better informed decision-making about circular alternatives compared to linear, business as usual options.
Guidelines - Environmental impacts of construction products and buildings are typically evaluated using life cycle assessments (LCA), and financial impacts by means of life cycle costing (LCC). Conventionally, their implementation is not without flaws. Despite European standards and recommendations, modelling closed material loops is not harmonised across the continent for example.
Environmental impacts of construction products and buildings are typically evaluated using life cycle assessments (LCA), and financial impacts by means of life cycle costing (LCC). Conventionally, their implementation is not without flaws. Despite European standards and recommendations, modelling closed material loops is not harmonised across the continent for example.
Also, social value assessments are many and varied, covering a plethora of aspects of societal costs and benefits. Moreover, most metrics in conventional societal impact or value studies, do not have a relevance when rethinking value networks in construction, and the economy in general. Therefore, a mayor revision of those assessment methods was indispensable.
Circular Building Assessment is facilitated through data extraction from Building Information Modelling (BIM) and Material Passports where available. Consequently, from a certain level of detail, an evaluation of the transformation capacity and reuse potential of the building and its key parts can affect the assessment outcomes for all aspects.
Moreover, the BAMB project aims to compare within the Circular Building Assessment method the overall impact of the replacement of new products with reclaimed ones, of service life extensions resulting from improved transformation capacity, and the future reuse of parts enabled by their increased reuse potential.
Definition - Use of the term air conditioning (AC) can be confusing.
Use of the term air conditioning (AC) can be confusing.
In some of the strictest definitions, air conditioning is used to describe systems that control the moisture content of air, that is, its humidity. This can include humidification and dehumidification. Humidity control can be important for; the comfort of building occupants, to reduce the incidence of condensation (both surface and interstitial), for specialist environments such as swimming pools, and where the protection of sensitive items requires particular conditions.
However, dehumidification of air is generally achieved by cooling. As the temperature of air falls, it is less able to 'hold' moisture, that is, saturation water vapour density falls, and so relative humidity rises. When relative humidity reaches 100%, the air will be saturated. This is described as the 'dew point'. If the air continues to cool, moisture will begin to condense, dehumidifying the air.
This means that humidity control and cooling are often considered together as air conditioning. Cooling and dehumidification are important contributors to thermal comfort. This is because the ability to perspire, and so to lose heat by evaporation from the skin, is limited by the humidity of the air.
As a result, remaining cool is dependent on both temperature and humidity (as well as a number of other factors, see Thermal comfort for more information). A combination of reduced air temperature, and reduced humidity helps people to remain cool.
The cooling of air alone, often described as air conditioning is more correctly referred to as comfort cooling. However, because it cools the air, comfort cooling may include some incidental dehumidification.
Other definitions of air conditioning describe it as the process of conditioning supply air to:
Regulate its humidity. - Regulate its quality (through filtration).
Regulate its quality (through filtration). - Regulate its temperature.
Regulate its temperature. - CIBSE Guide B. Heating, Ventilating, Air Conditioning and Refrigeration suggests that:
CIBSE Guide B. Heating, Ventilating, Air Conditioning and Refrigeration suggests that:
Air conditioning involves full control over the humidity within the conditioned space as well as temperature control. CIBSE suggest that 'close control air conditioning' might be defined as the control of temperature to within 1K and relative humidity to within 10%. This requires a complex process of dehumidification and cooling, reheating and humidification.
The Department for Communities and Local Government (CLG) guide, Improving the energy efficiency of our buildings, A guide to air conditioning inspections for buildings, December 2012 suggests that an air conditioning system is defined as a combination of all components required to provide a form of air treatment in which the temperature is controlled, or can be lowered, and includes systems which combine such air treatment with the control of ventilation, humidity and air cleanliness.
This includes fixed, self-contained systems, such as split systems and centralised systems. Mechanical ventilation systems that provide no mechanical cooling, but serve spaces that are cooled by other means are included. Any components contained in air conditioning systems that are only intended to provide heating are excluded.
Process - In mechanically ventilated commercial developments, air conditioning is often provided by air handling units (AHU) connected to ductwork that supplies air to and extracts air from internal spaces. Alternatively, air handling units can be used to supply and extract air direct to a space.
In mechanically ventilated commercial developments, air conditioning is often provided by air handling units (AHU) connected to ductwork that supplies air to and extracts air from internal spaces. Alternatively, air handling units can be used to supply and extract air direct to a space.
Air handling units typically comprise an insulated box that might include some, or all of the following components; filter racks or chambers, a fan (or blower), heating, cooling and dehumidification, sound attenuators and dampers. Air handling units that consist of only a fan and a heating or cooling element, located within the space they are serving, may be referred to as fan coil units (FCU).
Cooling itself can be generated either within the unit itself, or can be provided by connection to central chillers.
Value relates to assessment of the benefits brought by something in relation to the resources needed to achieve it. In the context of construction projects it is normally expressed as a ratio between a function and the whole life cost for that function.
Value = function / whole life cost -
Where the term 'whole life value' (WLV) refers to the process of assessing a project based on its long-term value and social impacts. This is different from whole life costs (WLC) which considers costs associated with the life of the project itself; its construction, operation, disposal, etc.
Whole life value is closely linked with sustainability and how environmentally-friendly the project is. In calculating the WLV the following considerations may be taken into account:
Energy costs associated with the project. - Facilities management costs and quality.
Facilities management costs and quality. - Potential costs of retrofitting.
Potential costs of retrofitting. - Durability and resilience.
Durability and resilience. - Fitness-for-purpose.
Fitness-for-purpose. - Long-term value to society (e.g. a road tunnel that reduces journey times and therefore, energy consumption).
Long-term value to society (e.g. a road tunnel that reduces journey times and therefore, energy consumption).
Issues that can sometimes conflict with whole life value might include; environmental impact, economic performance, technical viability, clients requirements, and so on.
The building sector is increasingly aware of whole life value, with lower emission rates, corporate social responsibility considerations, life cycle assessment, increasingly strict environmental standards and so on. In particular, WLV has been promoted as a method for assessing long-term projects such as private finance initiative (PFI) projects.
The Home Quality Mark One, Technical Manual SD239, England, Scotland & Wales, published by BRE in 2018, suggests that reused construction products are: 'Construction products that can be extracted from the waste stream and used again without further processing, or with only minor processing, that does not alter the nature of the construction product (e.g. cleaning, cutting, fixing to other construction products).'
Introduction - Reduce, reuse and recycle is a motto used by environmentalists to reduce waste, minimise consumption and ensure the best overall approach is adopted for the environment and human health. Such programmes when managed at national and/or local levels can save money, energy and natural resources.
Reduce, reuse and recycle is a motto used by environmentalists to reduce waste, minimise consumption and ensure the best overall approach is adopted for the environment and human health. Such programmes when managed at national and/or local levels can save money, energy and natural resources.
Reduce, reuse and recycle are part of the waste hierarchy guidance tool which ranks waste management options according to what is best for the environment and also considers resource and energy consumption. It aims to extract from products the maximum practical benefits and generate minimal waste. The priorities in the hierarchy are based on sustainability.
The waste management hierarchy features a distinct order of preference usually represented by a pyramid diagram which is designed to facilitate reduction and management of waste. The pyramidal structure emphasises options from those that are most favoured to those least favoured.
In the UK, this falls under the Waste (England and Wales) Regulations 2011, which came into force on 29 March 2011.
The origins of waste hierarchy guidance stretch back to 1975, when the European Unions Waste Framework Directive introduced the concept into European waste policy. It emphasised waste minimisation, protection of the environment and human health.
Reduce - In the first instance, reduction gives priority to preventing waste as a basic step. In other words, through judicious purchasing and use behaviours, the amount of waste can be reduced. Reduced waste means less material to process, ie prepare it for reuse, recycling, recovery and disposal.
In the first instance, reduction gives priority to preventing waste as a basic step. In other words, through judicious purchasing and use behaviours, the amount of waste can be reduced. Reduced waste means less material to process, ie prepare it for reuse, recycling, recovery and disposal.
Reduction/prevention may include; -
Using less material in design and manufacture. - Consuming only what is needed, avoiding pointless purchases. Sharing rarely-used items.
Consuming only what is needed, avoiding pointless purchases. Sharing rarely-used items.
Keeping products for longer. - Buying only products that can be reused.
Buying only products that can be reused. - Hire or lease items.
Hire or lease items. - Buy products with no or minimal packaging.
Buy products with no or minimal packaging. - Regular maintenance can extend the lifecycle of a product hence lower the need for new material.
Regular maintenance can extend the lifecycle of a product hence lower the need for new material.
Reuse - Reuse and preparing for reuse may involve:
Reuse and preparing for reuse may involve: -
Checking cleaning, repairing, refurbishing, whether whole items or parts.
Reusing items such as carrier bags, envelopes, newspaper, cardboard, bubble wrap, jars, pots, old clothes, packaging, tyres, used wood and building materials and so on.
Buying a wide range of products from clothes to building materials at specialist recycling centres.
Reusing containers. - Maintaining and repairing products as far as possible, eg, clothes, tyres, bricks, roof slates
Maintaining and repairing products as far as possible, eg, clothes, tyres, bricks, roof slates
Regular maintenance. - Reusing surplus material from other organisations.
Reusing surplus material from other organisations. - Recycle
Recycle - Turning materials that would otherwise be thrown away into new substances or products. The benefits include:
Turning materials that would otherwise be thrown away into new substances or products. The benefits include:
Reduced waste sent to landfill. - Conserves natural resources.
Conserves natural resources. - Less pollution from lower levels of extraction and manufacturing activities.
Less pollution from lower levels of extraction and manufacturing activities.
May create employment opportunities. - Other recovery methods
Other recovery methods - The three steps above, once implemented, can lead to other recovery methods, such as anaerobic digestion, incineration with energy recovery, and finally disposal involving landfill and incineration without energy recovery.
The three steps above, once implemented, can lead to other recovery methods, such as anaerobic digestion, incineration with energy recovery, and finally disposal involving landfill and incineration without energy recovery.
The waste hierarchy as described above applies to most materials. However, the UK government concedes that for some materials, it may be better for the environment if they undergo waste management options that are not in keeping with the waste hierarchy order. These materials include:
Food research has shown that anaerobic digestion is environmentally better than composting and other recovery options;
Garden waste and mixtures of food waste dry anaerobic digestion followed by composting is environmentally better than composting alone,
For lower grade wood, energy recovery options are more suitable than recycling. To determine the grade of wood handled, see Wood Recyclers Association grading structure for UK derived, non-virgin wood Applying the Waste Hierarchy: Evidence Summary, section 19.
Introduction - Recycling is the process of converting a waste material, such as glass, plastic, paper or metal, into a material that can be used for the same or alternative purpose.
Recycling is the process of converting a waste material, such as glass, plastic, paper or metal, into a material that can be used for the same or alternative purpose.
Recycling has become an important part of community and business efforts to lower levels of material consumption, energy usage, carbon generation and landfill. It is part of the waste hierarchy reduce, reuse, recycle. This suggests that it is most beneficial to the environment to reduce what we use in the first place. Where it is necessary to use things, we should then strive to re-use them, and only finally to recycle them if no further re-use is possible.
A recycled product will rarely be exactly the same as its original composition. For example, recycled paper contains ink residue and shorter fibres than virgin paper (made from wood pulp) and so may be less desirable for some uses. This 'inferiority' of some recycled materials is known as down-cycling, as a result of which, over time, some materials exhaust their recyclability and are no longer usable.
In some cases, however, materials can be up-cycled which means they are made into something more valuable than the original product (for example, using old bottles as lamps or an old suitcase as a medicine cabinet). The most common types of recyclable materials are:
Paper - Paper is sorted on the basis of its type, weight, use, colour and whether it has been previously recycled. Recycled paper results in significant net savings in terms of water and energy used, as well as the emission of pollutants.
Paper is sorted on the basis of its type, weight, use, colour and whether it has been previously recycled. Recycled paper results in significant net savings in terms of water and energy used, as well as the emission of pollutants.
Glass - The easy recyclability of glass means that there is almost no down-cycling and significant energy and cost savings over making new glass.
The easy recyclability of glass means that there is almost no down-cycling and significant energy and cost savings over making new glass.
Steel - Steel is relatively easy to recycle. Once sorted, scrap steel is melted down and re-refined into large sheets or coils which are then shipped to manufacturers.
Steel is relatively easy to recycle. Once sorted, scrap steel is melted down and re-refined into large sheets or coils which are then shipped to manufacturers.
Plastic - As the production costs of plastics are generally low, and due to its non-biodegradability, recycled plastic is usually reprocessed into a completely different form from their original state.
As the production costs of plastics are generally low, and due to its non-biodegradability, recycled plastic is usually reprocessed into a completely different form from their original state.
Aluminium cans - When these are recycled they can save up to 95% of the energy required to make new cans.
When these are recycled they can save up to 95% of the energy required to make new cans.
Electronics - This is less common due to the labour-intensive methods required to separate the different components, and extract the often toxic materials included such as mercury, lead and chemical refrigerants.
This is less common due to the labour-intensive methods required to separate the different components, and extract the often toxic materials included such as mercury, lead and chemical refrigerants.
EPS - EPS can easily be recycled into new foam packaging or durable consumer goods like cameras, coat hangers, CD jewel cases and more. You can recycle your EPS packaging by using EPS compactor
EPS can easily be recycled into new foam packaging or durable consumer goods like cameras, coat hangers, CD jewel cases and more. You can recycle your EPS packaging by using EPS compactor
Other - Organic waste can be composted and turned into fertilizer. Rubber tyres can also be shredded and reused.
Organic waste can be composted and turned into fertilizer. Rubber tyres can also be shredded and reused.
History of recycling - Although recycling as a widespread concept has arisen only relatively recently with the new sense of environmental conscientiousness, it has been present in various forms for thousands of years. Recycling was a practical necessity prior to the Industrial age due to the fact that goods were not readily available at such cheap prices.
Although recycling as a widespread concept has arisen only relatively recently with the new sense of environmental conscientiousness, it has been present in various forms for thousands of years. Recycling was a practical necessity prior to the Industrial age due to the fact that goods were not readily available at such cheap prices.
The Industrial Age fostered a new era of mass production which gave rise to a culture of disposability since goods could be produced and purchased cheaply, making more economic sense to throw them away rather than recycle them.
With the economic depressions of the 1930s and 40s, citizens of developed nations began to rely on recycling techniques as new goods were suddenly unaffordable. During the two world wars, many materials were rationed and recycled. In the post-war boom however, recycling slipped from widespread public consciousness, until the expansion of the environmental movement of the 1960s and 70s when recycling became a mainstream idea once again. During the late-20th century and early 21st century, as the threats of climate change have become more apparent, recycling programmes have become established and accepted as a central part of society.
Benefits of recycling - The main reasons for the promotion of recycling include:
The main reasons for the promotion of recycling include:
Conservation of raw materials - Raw materials such as trees, rocks, minerals and oil are 'harvested' and as a result, reserves of such materials are in decline. Mining and other extraction operations continue to have a negative impact on large areas of many countries around the world, such as deforestation.
Raw materials such as trees, rocks, minerals and oil are 'harvested' and as a result, reserves of such materials are in decline. Mining and other extraction operations continue to have a negative impact on large areas of many countries around the world, such as deforestation.
Conservation of energy - The amount of energy required to create new products is frequently more than required for recycling. This does depend on the material though, as the manufacturing of plastic for instance can be inexpensive.
The amount of energy required to create new products is frequently more than required for recycling. This does depend on the material though, as the manufacturing of plastic for instance can be inexpensive.
Reduction of pollution - Pollution can be reduced as a result of recycling being more efficient and requiring less energy to operate than manufacturing processes.
Pollution can be reduced as a result of recycling being more efficient and requiring less energy to operate than manufacturing processes.
Reduction of landfill - Recycling helps to reduce the requirement for landfill. Landfill sites harm the surrounding environment and habitats, particularly as a result of the chemicals that can be produced when waste breaks down. These can contaminate land and water and cause and can be hazardous.
Recycling helps to reduce the requirement for landfill. Landfill sites harm the surrounding environment and habitats, particularly as a result of the chemicals that can be produced when waste breaks down. These can contaminate land and water and cause and can be hazardous.
Recycling regulations - Interpretation of the various EU waste directives has been devolved in the UK, which means that waste policy differs in terms of pace, strategy and targets between England, Wales, Scotland and Northern Ireland. Generally each individual council in the UK has the responsibility to provide recycling services, as opposed to relying on instructions from county councils or central government.
Interpretation of the various EU waste directives has been devolved in the UK, which means that waste policy differs in terms of pace, strategy and targets between England, Wales, Scotland and Northern Ireland. Generally each individual council in the UK has the responsibility to provide recycling services, as opposed to relying on instructions from county councils or central government.
Definition - Material(s) banks are repositories or stockpiles of valuable materials that might be recovered. If those materials replace primary resources used during the construction, operation or refurbishment of buildings and their parts, the need for primary resource mining, for example, of rare earth elements, can be eliminated.
Material(s) banks are repositories or stockpiles of valuable materials that might be recovered. If those materials replace primary resources used during the construction, operation or refurbishment of buildings and their parts, the need for primary resource mining, for example, of rare earth elements, can be eliminated.
This idea of urban mining implies effective material reuse and thus the realisation of material loops. Nevertheless, to enable and facilitate the harvesting of materials or building parts, it is necessary to design them in a reversible way.
Guidelines - Alternatively, the term 'material(s) bank' might also refer to bank institutions, managing the financial resources they are entrusted, for example by lending them to other individuals and businesses. Like financial resources, it is imaginable to entrust material resources to the building stock; and once materials are retrieved, they might have a higher value due to inflation.
Alternatively, the term 'material(s) bank' might also refer to bank institutions, managing the financial resources they are entrusted, for example by lending them to other individuals and businesses. Like financial resources, it is imaginable to entrust material resources to the building stock; and once materials are retrieved, they might have a higher value due to inflation.
This project has the ambition to implement the vision of buildings as material banks during construction and refurbishment projects. Therefore, its outcomes will support their reversible design and the establishment of circular value networks through Materials Passports and Building Information Management.
Related terms - Recovery: the technological process of separating valuable materials or building parts from the building or assembly they were once integrated in, or from waste, in such a way that maintains or increases their value again.
Recovery: the technological process of separating valuable materials or building parts from the building or assembly they were once integrated in, or from waste, in such a way that maintains or increases their value again.
Materials harvesting: recovering materials from the existing stock of building with the aim to reuse, recycle or biodegrade them and realise a technical or biological material loop.
Component harvesting: recovering assemblies of materials from the existing stock of buildings with the aim to reuse or recycle them and realise a technical material loop.
Urban mining: recovering materials or assemblies of materials from the building stock instead of using virgin materials.
Rare earth elements: chemical elements found in the earths crust that are vital to many modern technologies but are difficult to find in quantities enabling their economic development.
BREs Environmental impact of biomaterials and biomass defines a life cycle inventory (LCI) as the product system input and output flow data used in carrying out the LCA.
Where the life cycle assessment (LCA) is compilation and evaluation of the inputs, outputs and potential environmental impacts of a product system throughout its life cycle.
The term 'Green supply chain management' (GSCM) refers to the concept of integrating sustainable environmental processes into the traditional supply chain. This can include processes such as product design, material sourcing and selection, manufacturing and production, operation and end-of-life management.
Instead of simply attempting to mitigate the environmental impact of the supply chain, GSCM involves driving value creation throughout the supply chain organisations to reduce total environmental impact.
While the specific goal of GSCM is often the reduction of CO2 emissions, other tangible benefits for an organisation include; greater efficiency of assets, less waste production, greater innovation, reduction of production costs, reuse of raw materials, increased profitability, perception of added value to the client base, and so on.
Integral to the success of GSCM is the approach taken by each party to their upstream and downstream partners in the supply chain. A much greater degree of collaboration, transparency and integration of supply chain processes and systems is required for the initiative to be effective.
Facilities Management Software is a highly useful computer program or programs that are designed to be implemented by the manager or management company of a set of facilities. The facilities can be anything from sanitation to warehouses to parking lots, and so on. The software will help the facility management company to create timetables for improvement or maintenance, costs of operation and billing, and any number of other valuable resources to streamline the company's day-to-day business.
What is Facility Management? - The practice or coordinating the physical workplace with the people and work of the organization; integrates the principles of business administration, technology, behavioral and architecture. In other words managing the facility in efficient manner so that the company can focus and deliver core business. Challenges faced in managing facility?
The practice or coordinating the physical workplace with the people and work of the organization; integrates the principles of business administration, technology, behavioral and architecture. In other words managing the facility in efficient manner so that the company can focus and deliver core business. Challenges faced in managing facility?
Managing facility is not a easy task, availability of right tool and information at the right time is the most important. Maintains the culture, ethics, providing the strong support in the decided budget is key role of facility management. Business may work 10 hours in a day but facility needs to be manage 24 hours.
Facility Management and administration - Fooding & Lodging for the employees
Fooding & Lodging for the employees - Cleaning the premises
Cleaning the premises - Security
Security - Stationary
Stationary - Mail Room system
Mail Room system - Electricity consumption
Electricity consumption - Water supply
Water supply - Electric equipment
Electric equipment - Installation of devices
Installation of devices - Construction
Construction - Transport management
Transport management - Fire equipment management
Fire equipment management - Crockery
Crockery - Consumable Items
Consumable Items - UPS/generators
UPS/generators - Vendor Management
Vendor Management - There is a long list to go, managing the right facility reduces the risk in the organization. Above work mentioned may be different for different organization; however core structure remains the same. We will discuss later the important risks for any organization.
There is a long list to go, managing the right facility reduces the risk in the organization. Above work mentioned may be different for different organization; however core structure remains the same. We will discuss later the important risks for any organization.
Facility Manager - Facility manager is the person, who is responsible for managing the facility in the organization, he is responsible for the smooth workflow of above points, so that the business can perform their core business. Some major challenges that are faced by facility manager are:
Facility manager is the person, who is responsible for managing the facility in the organization, he is responsible for the smooth workflow of above points, so that the business can perform their core business. Some major challenges that are faced by facility manager are:
Managing service and maintenance reminders - Round the clock reservation of facilities
Round the clock reservation of facilities - Gap in providing feedback to the concerned person for the right action
Gap in providing feedback to the concerned person for the right action
Reducing paper work - Tracking every requisition and their status
Tracking every requisition and their status - Maintaining updated records of feedback and action taken
Maintaining updated records of feedback and action taken - Maintaining records of absenteeism
Maintaining records of absenteeism - Providing advance intimation of service due
Providing advance intimation of service due - Dependency on subordinates for information
Dependency on subordinates for information - In the current era companies always focuses on the budget and the costing, they are aware that FM is considered as the 2nd largest expense incurred by organizations after personnel cost, right FM would assist you to have the following benefits:
In the current era companies always focuses on the budget and the costing, they are aware that FM is considered as the 2nd largest expense incurred by organizations after personnel cost, right FM would assist you to have the following benefits:
Helps considerably reduce the important risk in an organization
Assists in achieving lower costs of operations - Improves communication
Improves communication - Increases accountability
Increases accountability - So either you require so many human resources to manage or the new facility management technology to manage and reduce cost. Software and hardware companies started making application to manage facility effectively and also started a trend to outsource their facility work to the companies which are professional and expertise in handing facility management work.
So either you require so many human resources to manage or the new facility management technology to manage and reduce cost. Software and hardware companies started making application to manage facility effectively and also started a trend to outsource their facility work to the companies which are professional and expertise in handing facility management work.
In this era of information facility management technology, software solutions help facility managers to work more effectively and efficiently. Technologically advanced facilities management software solutions help organizations effectively manage their physical assets and maintenance operations. Facilities management software for filling the gaps between the human and the systems and to check the following
Scheduled activity carried out by the Technicians - End user complains 24 hrs
End user complains 24 hrs - Vendor billing and services
Vendor billing and services - Forecast for consumable
Forecast for consumable - Calculation of break downs during last one year
Calculation of break downs during last one year - Occupancy report for company common facilities
Occupancy report for company common facilities - Details of the inventory and consumption
Details of the inventory and consumption - One contact for all services
One contact for all services - Quality service
Quality service - Effective reporting
Effective reporting - Feedback Management
Feedback Management - Right people for right job
Right people for right job - Reduce inventory cost
Reduce inventory cost - Right people for right job
Right people for right job - Best practices
Best practices - In short facilities management software can increase efficiency and help organizations to achieve benchmarks in terms of service and quality.
In short facilities management software can increase efficiency and help organizations to achieve benchmarks in terms of service and quality.
A guide to the use of urban timber (FB 50) was written by Geoff Cooper and published by BRE on 31 July 2012. The guide defines 'dunnage' as: 'Waste wood material usually sawn into uniform squares of a given length and used to raise packs of sawn timber off the ground to allow fork-lift access. Dunnage is also used to separate packs of timber in the kiln-drying process.'
Safety in the storage and handling of steel and other metal stock, second edition, published by the Health and Safety Executive (HSE) in August 2016, defines dunnage as: Packing supports used to separate/secure stock on the back of a vehicle while in transit. This can be made of wood, plastic, steel bars or hollow steel sections. Use of dunnage provides access for easier/safer attachment of lifting accessories and helps to prevent load movement. Also used as an alternative term for batten or bearer.
In the UK, the term duplex refers to an apartment (not a house) that includes two floors of accommodation, joined by an internal staircase.
Historically, this would have been referred to as a maisonette, but the term duplex has become increasingly popular because of its perceived Americanism, and is generally applied to apartments with a more modern design, whereas a maisonette might be more traditional.
An apartment with three floors can be referred to as a triplex. There is some dispute about whether an apartment with a mezzanine level should be referred to as a duplex. Where a duplex is on the top floor of a high-rise building, it might also be referred to as a penthouse.
Strangely however, and rather confusingly, in the USA, a duplex is a dwelling comprising two apartments with separate entrances, whether the apartments are side by side, or one above the other.
Introduction - This article introduces the concept of Dispute Resolution Boards (sometimes referred to as Dispute Review Boards) and Dispute Adjudication Boards, how they are established, and how they operate in practice.
This article introduces the concept of Dispute Resolution Boards (sometimes referred to as Dispute Review Boards) and Dispute Adjudication Boards, how they are established, and how they operate in practice.
Dispute Resolution Boards (DRB) administer a type of dispute resolution without any specific description. DRBs have evolved over time and can be formulated in a number of different ways. The procedure is based on contract rather than statute, and the parties to a contract are able to agree to a formulation that suits their particular project. A few standard contracts have DRBs as part of their terms, of which the most prominent are the FIDIC contracts and the World Bank (Procurement of Works) contract.
It seems to be accepted that the first DRB was set up in 1975 for the Eisenhower Tunnel in Colorado, USA. This followed the first tunnel bore that had been constructed between 1968 and 1973. The project was a disaster, in that it overran in both time and money, with many disputes arising. When it came to the second bore, notice was taken of a study entitled Better Contracting for Underground Construction published in 1974.
This report highlighted the incidence of claims, disputes and litigation together with the additional costs that inevitably flowed from those claims. Based on the report, it was decided that the second bore of the Eisenhower Tunnel contract would incorporate a DRB. The hope was that the high level of cost overrun and disputes experienced on the first bore could be minimised by use of the DRB.
It was a tremendous success. Although disputes did arise, they were dealt with very swiftly and effectively by the DRB, to the extent that there was no ensuing litigation.
The DRB was set up in the form of a Review Board rather than an Adjudication Board, and their findings were recommendations rather than binding decisions. The losing party was not obliged to follow the recommendation. The dispute could thereafter be taken to a higher authority where a binding decision could be made.
The use of DRBs on major projects confined to the USA increased. The World Bank took note and in 1980 decided that a project known as the El Cajon Dam and Hydro Scheme in Honduras was a suitable candidate for a DRB. The World Bank was a major funder of the project with a Honduran owner (who had not undertaken such a large project previously), an Italian contractor and a Swiss engineer. It is easy to see how misunderstandings could occur with such a diverse cultural mix, and the World Bank insisted that in order to obtain funding a DRB should be formed to deal with issues on the project as they arose.
That project was also a success. DRBs were launched into the international construction arena and broke out of their American birthplace.
As DRBs became more commonly used on international construction projects, various institutions began to take more notice of them. In 1990, the World Bank published its Procurement of Works, which for the first time incorporated a procedure for DRBs in the form of a modified FIDIC contract. This procedure incorporated non-binding recommendations.
FIDIC itself followed this with the publication of an amendment to its form in which the concept of Dispute Adjudication Boards (DABs) was introduced. These differed from the Dispute Review Boards in that a temporarily binding decision was introduced, very much in the same way as domestic adjudication in the United Kingdom.
In 2000, the World Bank revised its DRB procedure, introducing the idea of interim binding recommendations, displacing the engineer from a former role in which decisions on disputes were required. In the same year, FIDIC published a suite of contracts incorporating DABs, whereby interim binding decisions in respect of disputes could be made. The costs of the DAB are shared equally between the parties.
In 2003, the European Union published a directive that prescribed the use of these FIDIC contracts incorporating DABs on all construction projects that receive EEC funding.
The ICC rules allow for a choice of non-binding recommendations, adjudication decisions and a combined approach that allows the DAB to act as an adjudication board at the request of one party, with the proviso that if the other party objects, the board will decide in what capacity it is to hear the dispute.
To date, well over 1,000 construction and engineering projects worldwide have used DRBs with a total construction cost of some US$100 billion. The success of DRBs is illustrated by the fact that fewer than 3% of disputes that arose became the subject of an arbitration or litigation.
DRBs are most suited to large, complex construction and engineering projects on an international scale, although more domestic projects are incorporating these ideals; for example the Channel Tunnel Rail Link had a DRB. This was a huge project. Two panels were appointed, one to deal with the technical issues (three engineers) and the other to deal with disputes concerning the financial provisions of the project.
Composition of a dispute resolution board - The DRB is a creature of the contract. Usually, the contract will provide for three members, two technical and one legal, usually the chairman. This formulation allows for technical disputes to be fully understood and resolved without the need for external advice, and similarly disputes involving or including legal issues being capable of resolution without external advice. The idea is for the board to be able to deal with any dispute that arises.
The DRB is a creature of the contract. Usually, the contract will provide for three members, two technical and one legal, usually the chairman. This formulation allows for technical disputes to be fully understood and resolved without the need for external advice, and similarly disputes involving or including legal issues being capable of resolution without external advice. The idea is for the board to be able to deal with any dispute that arises.
Clearly, each board member needs to be a respected member of their own profession, with qualifications and experience to match the project in hand.
Essentially, the DRB can be likened to a project management tool that is used to ensure that the project remains on track, influencing the parties to the project to carry out their contractual obligations properly.
The three-member DRB will visit the project regularly and deal with any difficulties that have arisen. Occasionally, it will have to convene outside of its regular visits if a particular dispute requires it. The advantage to the parties is that the DRB gains an ongoing knowledge of the project as the members are exposed to the facts of any emerging disputes at a very early stage.
The operational philosophy behind a DRB is to provide interim solutions that are in tune with the interests of the project in a quick and effective manner. It is a process that is intended to find solutions to problems rather than form an adversarial forum. DRBs are designed to keep the parties working constructively together while finding solutions to problems as they occur, rather than allowing those problems to escalate in an ultimately destructive manner.
Selection of the dispute resolution board - The success of a DRB is dependent not only on the procedure that has been put in place but also on the members of the DRB itself. Of course, the importance of the willingness of the parties themselves to work constructively with the DRB and make commercial compromises should not be forgotten.
The success of a DRB is dependent not only on the procedure that has been put in place but also on the members of the DRB itself. Of course, the importance of the willingness of the parties themselves to work constructively with the DRB and make commercial compromises should not be forgotten.
The selection of the members of the DRB is crucially important to the parties, and therefore an appointment procedure is required within rules set out in the contract. Normally, each party nominates one member and those members then choose a third member as chairman. This allows each party to have the comfort of a board member who is in tune with their thinking, while the chairman is independent of both. In default of agreement between the two members, a nominating body should independently select and appoint the chairman. Again, that procedure must be part of the written contract.
When appointing members for the DRB it is useful to consider their experience not only in construction and engineering but also in contract management and the applicable law of the contract. A mix of all these elements may be required in varying degrees. Ideally the board should not consist entirely of like-minded individuals but be a combination, such as two construction or engineering professionals and a lawyer versed in construction and engineering law as well as the law of the contract.
Dispute resolution board procedure - Once the members of the DRB have been appointed, the procedure should allow for regular visits to site, including time to deal with any differences that have arisen. This should also allow for less formal opinions to be given by the DRB in respect of what might be potential disputes.
Once the members of the DRB have been appointed, the procedure should allow for regular visits to site, including time to deal with any differences that have arisen. This should also allow for less formal opinions to be given by the DRB in respect of what might be potential disputes.
The use of the DRB for informal discussions between the parties (together or separately), with or without the engineer should be encouraged. Where an opinion has been sought, the DRB may respond in writing (or orally if followed up in writing), and by that informal process the potential dispute may be avoided. If not, the formal dispute procedure requiring a written recommendation by the DRB, or a written reasoned decision by the DAB, will commence.
The formal procedure usually involves the dissatisfied party issuing a written notice containing details of the dispute to the other party and to the DRB. That notice may be dependent on timing should the contract so indicate. For example, FIDIC only allows 28 days after the engineers decision in which to issue a notice.
Having issued the notice, the claimant has to prepare a position statement in which they set out their legal and factual arguments, supported by evidence. On receipt, the defendant will prepare their position statement responding to the claimants narrative, setting out their arguments and the evidence relied upon.
Having received the two position statements, the DRB will consider the matters raised. If necessary the members of the DRB will meet before the hearing to discuss procedural or substantive matters.
The DRB will prepare a list of questions or further documents required so that the hearing will be able to deal fully with all matters arising. The hearing will normally be held within 30 days (15 days in the ICC rules) of the defence being served, usually on or near the project. The length of the hearing is dependent on the complexity of the matters before the DRB, but is very unlikely to exceed one week. In fact, most hearings do not exceed two or three days.
The hearing follows the usual course: a submission by the claimant, a submission by way of reply from the defendant, with perhaps questions and points of clarification raised by the DRB. If necessary the engineer will be allowed to make submissions or answer questions.
After the hearing is brought to a close, the DRB will continue with its deliberations and a draft recommendation or adjudication decision will be prepared. This is necessary, as the three-man board will thereafter return home to prepare their individual reports for later discussion and to finalise their recommendation or adjudication decision.
Time is always of the essence in making a recommendation or decision, as the parties will be continuing with the works, and the decision needs to be known sooner rather than later. In any event, the rules should have a time limit for the board to make its decision, subject to the claimant being able to grant the DRB a limited extension to that time if special circumstances arise which prevent a recommendation or decision being made in the prescribed time. The recommendation or decision will be produced by way of a written report.
Where the Board provides recommendations, these can be without sanction or a time limit. To provide certainty, a time limit can be prescribed for any written objection to be made by either party. If no objection is raised, then the recommendation can become binding on the parties. In any event, the recommendation or decision should be stated in the contract to be acted upon immediately it is published.
Procedural fairness - As with any dispute resolution process, to be effective the decision-making process should be seen to be fair. Natural justice has been the source of much comment and legal analysis, especially in respect of statutory adjudication in the UK.
As with any dispute resolution process, to be effective the decision-making process should be seen to be fair. Natural justice has been the source of much comment and legal analysis, especially in respect of statutory adjudication in the UK.
Dispute Review Boards are not a creature of statute, they are a creature of the contract. In this respect, they seem to have more in common with expert determination than arbitration or adjudication. Expert determination has no remedies for procedural irregularity and cannot be set aside under those circumstances, unlike arbitration. An expert may investigate and come to their conclusions without reference to the parties. Their power is absolute, as it derives from the contract.
Unless the contract states otherwise, the expert cannot be challenged if the parties have agreed to accept the determination as being final. Similarly, the only challenges to the DRBs jurisdiction are those set out in the contract. If the parties wish the DRBs decision to be final and binding, this should be reflected in the contract.
The courts may decide to follow the lead of adjudication practice in the UK and scrutinise DRB decisions for procedural fairness. An example of the courts refusing to accede to a DRB process for lack of procedural fairness can be found in the case of Sehulster Tunnels and Pre-Con (Joint Venture) v Traylor Brothers Inc and Obayashi Corporation (Joint Venture) (12 September 2003) Court of Appeals of California, Fourth Appellate District.
In this case, a DRB had been set up on a large outfall system taking treated waste out by tunnel into the ocean in Southern San Diego County, California. The contract was worth some US$90 million. The DRB was to be by the appointment of the employer, the city of San Diego, and the contractor, Traylor Brothers Inc and Obayashi Corporation, a joint venture. The subcontract for the manufacture of the concrete rings forming the tunnel lining was with Sehulster Tunnels and Pre-Con, also a joint venture.
The subcontract reflected the DRB procedure found in the main contract, but importantly did not allow Sehulster to appoint one of the members to the DRB. When a dispute arose, the contractor and the employer insisted that the DRB be used but refused Sehulsters request to appoint a member of the DRB. Sehulster therefore ignored the DRB provisions and litigated in the courts.
The court at first instance found in Sehulsters favour. The matter went further. It was argued at the Court of Appeal that as the subcontract incorporated the DRB by reference, and in order for Sehulsters claim to proceed, the DRB mechanism had to be used. In response, Sehulster argued that the first instance decision should be upheld and that the DRB was presumptively biased against Sehulster, as Sehulster was unable to appoint a member to the Board. Sehulster further argued that the condition precedent for the DRB contained within the subcontract could not be enforced and Sehulster had every right to litigate in the courts.
The Court of Appeal agreed with Sehulster, saying:
Sehulster in this context should not be required to pursue a charade characterised as meaningful ADR. Secondly, although the DRBs recommendation is non-binding, it is not without influence because the Prime Contract provides for its admissibility into evidence in any later dispute resolution or legal proceeding. Finally, it does not follow that because the DRB process does not constitute binding arbitration, Grahams notions [Graham v Scissor-Tail Inc (1981) 28 Cal.3d 807, 817-819] regarding presumptive bias are inapplicable in this context, therefore permitting enforcement of the condition precedent of pursuing the DRB process to preclude resolution of Sehulsters claim by litigation
contractual ADR must operate within minimum levels of integrity to pass judicial muster, the court held that the minimum levels of integrity had not been achieved .
This case also makes observations in respect of DRBs in general, and these are worth repeating here:
The DRB process constitutes a form of alternative dispute resolution (ADR) most commonly employed in tunnelling and other large, complex, heavy construction projects. First utilised in the mid-1970s, it has proven particularly advantageous in contracts' performance of which will take a long period of time, and in which disputes are inevitable and multiple instalment payments are contractually required on completion of performance milestones or components of the work.
Generally, the DRB serves as a safety net to resolve problems or matters about which reasonable people could differ before they harm the business relationship between the parties and result in acrimonious litigation. It is composed of three experts, selected by the parties at the beginning of the project, who become familiar with it, monitor its progress and are available to provide advisory decisions on short notice concerning disputes the parties are unable to resolve themselves. The availability of the DRB and its familiarity with the project enable prompt resolution of disputes, which furthers the goal of preserving cooperative relationships between the contracting parties.
The DRB process resembles the arbitration process with several significant differences. First, the DRB is a standing tribunal contractually required to be formed and in place within a few months after the owner gives the contractor notice to proceed. Second, the process envisions: an introductory/orientation meeting for the DRB members to become acquainted with the owner, the contractor, and their key personnel; a brief history of the project, including significant potential technical, environmental, political or social issues that might arise from it; and the scope and anticipated schedule of construction. Third, the DRB meets regularly throughout construction of the project. The frequency of meetings is dictated by the projects size, complexity, schedule and number of claims or problems. Fourth, unlike standing arbitrators who make immediately binding decisions, the DRB issues advisory opinions or non-binding recommendations.
As exemplified here, the DRB is a creature of contract designed to provide recommendations to resolve particular disputes. Because the DRBs recommendations are non-binding and may be rejected by either the owner or the contractor, it is important for the credibility of the DRB that the parties perceive its members as generally qualified and neutral.
The DRB process is designed to promote the parties confidence in it by providing their equal involvement in the selection of the individual DRB members who have experience in that type of construction, contract interpretation and dispute resolution.
Enforcement - The recommendation or decision of a DRB is a contractual matter, and therefore any enforcement, will be seen in the light of a breach of contract. Enforcement will usually be a matter of the jurisdiction within which the DRB is operating. In England and Wales, the courts will not allow a party to avoid the DRB machinery, and summary judgement will recognise any express contractual provisions.
The recommendation or decision of a DRB is a contractual matter, and therefore any enforcement, will be seen in the light of a breach of contract. Enforcement will usually be a matter of the jurisdiction within which the DRB is operating. In England and Wales, the courts will not allow a party to avoid the DRB machinery, and summary judgement will recognise any express contractual provisions.
Conclusion - Those that have been involved with DRBs generally agree that on large projects they assist the parties to resolve their differences, enabling the project to be completed with much less chance of an acrimonious dispute developing into a major arbitration or litigation.
Those that have been involved with DRBs generally agree that on large projects they assist the parties to resolve their differences, enabling the project to be completed with much less chance of an acrimonious dispute developing into a major arbitration or litigation.
When a difference does become a dispute, it is dealt with quickly and so prevents the matter getting out of hand. The parties remain focused on the project rather than the dispute.
As to the members of the DRB, they are familiar with the progress and technical issues associated with the project; when a recommendation or decision is needed, it is made on the basis of the submissions but also on the knowledge that has been built up by the DRB.
DRBs provide a confidential forum in which difficulties or disputes can be resolved. They are not set up to apportion blame but rather to resolve issues that have arisen in a way that allows the project to proceed smoothly.
Introduction - Design principles are the fundamental ideas and elements that can be applied to achieve successful design.
Design principles are the fundamental ideas and elements that can be applied to achieve successful design.
The elements that together comprise a design include:
Line: A marker between two points. - Shape: Geometric (i.e. squares and circles), or organic (i.e. free-formed or natural shapes).
Shape: Geometric (i.e. squares and circles), or organic (i.e. free-formed or natural shapes).
Direction: Horizontal, vertical or oblique. - Size: Dimensions in relation to another element.
Size: Dimensions in relation to another element.
Texture: Surface quality, i.e. rough, smooth, and so on.
Colour: Hue, value (lightness or darkness), intensity (brightness or dullness).
The application of design principles to these elements will generate the design.
Common design principles include: -
Balance - Balance provides stability and structure to a design by placing the elements in such a way that the visual weight, in terms of objects, colours, textures and space, is distributed, i.e. symmetry. For example, a large shape positioned close to the centre can be balanced by a small shape close to the edge.
Balance provides stability and structure to a design by placing the elements in such a way that the visual weight, in terms of objects, colours, textures and space, is distributed, i.e. symmetry. For example, a large shape positioned close to the centre can be balanced by a small shape close to the edge.
Unity - This establishes an agreement between elements so that no individual element is viewed as more important than the design as a whole. Proximity is achieved, not necessarily by placing the elements together, but by connecting them visually:
This establishes an agreement between elements so that no individual element is viewed as more important than the design as a whole. Proximity is achieved, not necessarily by placing the elements together, but by connecting them visually:
Repetition: Strengthens a design by tying together individual elements to create association and consistency.
Rhythm: This is a feeling of organised movement created when one or more elements are used repeatedly. Variety is essential to keeping rhythm interesting.
Continuation: The sensation of a line or pattern extending.
Perspective: The sense of distance between elements.
Proportion: The sense of unity achieved when elements, or parts of elements, relate to each other in terms of size, amount or number.
Movement - This is the visual flow or path taken by the observers eye. It can be directed to focal areas by means of placement of dark and light areas, and positioning. Movement can be directed by the use of lines, edges, shapes and colours.
This is the visual flow or path taken by the observers eye. It can be directed to focal areas by means of placement of dark and light areas, and positioning. Movement can be directed by the use of lines, edges, shapes and colours.
Emphasis/contrast - This is the part of the design that catches attention, usually achieved by contrasting areas in terms of size, colour, direction, form, density, texture, shape, and so on.
This is the part of the design that catches attention, usually achieved by contrasting areas in terms of size, colour, direction, form, density, texture, shape, and so on.
Space - This refers to the placing of elements such that there is space around or within them.
This refers to the placing of elements such that there is space around or within them.
Alignment - Alignment enables order and organisation, which creates a visual connection between the elements.
Alignment enables order and organisation, which creates a visual connection between the elements.
The term decrement delay refers to the time it takes for heat to pass through an element of a building (such as an external wall or roof). Typically this is taken to be the delay in hours between the peak temperature of the outer surface of the element on a summer day and the resulting peak temperature of the internal surface.
This concept reflects increasing awareness that the thermal behaviour of buildings is dynamic, rather than static, and that thermal mass, as well as thermal insulation, has a significant impact on the energy efficiency of a building. For example, two buildings with identical U-values may perform very differently depending on their decrement delay, with a longer delay likely to reduce peak loads on building services systems.
Materials with a low lambda value (sometimes referred to as thermal conductivity or k-value), high specific heat capacity and high density will tend to have a high decrement delay.
The term decrement factor refers to the amount by which conditions are moderated by an element of a building. So in the case of the peak temperature on the outer surface of a building on a summer day, this would be the amount by which the peak is reduced by the time it reaches the inner surface. It is expressed as the ratio between the internal surface cyclic temperature variation compared to the external surface.
To reduce summer overheating, a low decrement factor is required, and a decrement delay of 6 to 12 hours.
Introduction - Deflection in engineering terms is the degree to which an element of structure changes shape when a load is applied. The change may be a distance or an angle and can be either visible or invisible, depending on the load intensity, the shape of the component and the material from which it is made.
Deflection in engineering terms is the degree to which an element of structure changes shape when a load is applied. The change may be a distance or an angle and can be either visible or invisible, depending on the load intensity, the shape of the component and the material from which it is made.
Deflection is a crucial consideration in the design of a structure and failure to apply due attention to it can be catastrophic.
Different types of load can cause deflections. These include point loads, uniformly distributed loads, wind loads, shear loads as well as ground pressure and earthquakes, to name but a few. When a load produces a deflection that is too great, the component may fail.
Components and structures that suffer deflection include, beams, columns, floors, walls, bridge decks, tunnel walls, dams and so on. San Franciscos Golden Gate Bridge can sway by as much as 4m laterally under strong winds.
Non-structural components can also deflect, for example cladding panels on a building may deflect inwards when subject to intense wind loading.
Given the possibility of structural failure, building codes usually determine what the maximum allowable deflection should be to ensure the safety of a buildings users and overall structural integrity. For a beam, this is usually expressed as a fraction of the span, eg the beams deflection should not be greater than 1/360th of the span; so, if the span is 5m, the deflection should not be greater than 13.9mm. This will usually be measured at the mid-point of the beam.
A structural element will deflect less under load if its stiffness or rigidity is increased. This can usually be achieved by strengthening its section or increasing its size; the latter may also increase its cost.
The material itself must also be considered. For example, because aluminium is around three times more flexible than steel, it is often designed for deflection rather than strength. In contrast, glass is relatively inflexible: even slight deflections in a steel frame could cause the glass to fracture.
Introduction - Construction projects are often subject to delays, irrespective of whether the contractor is or is not to blame. A delay claim for one day (or however number of days are involved) means the construction scheduled for that day was not completed, which could have severe financial implications and adversely affect the project's progress.
Construction projects are often subject to delays, irrespective of whether the contractor is or is not to blame. A delay claim for one day (or however number of days are involved) means the construction scheduled for that day was not completed, which could have severe financial implications and adversely affect the project's progress.
Delay analysis identifies why delays occur on a construction project and the impact they are expected to have on the overall programme. The outcome of the analysis may lead to legal action brought by one party to the contract.
Who is responsible - Delays in construction can be the contractors fault:
Delays in construction can be the contractors fault:
Insufficient labour on site. - Cash-flow issues.
Cash-flow issues. - Inadequate project planning.
Inadequate project planning. - Not the contractors fault:
Not the contractors fault: -
Unusual weather conditions. - Interruption in material supply, particularly if material is imported.
Interruption in material supply, particularly if material is imported.
Strikes. - Conflicting or missing information in contract documents.
Conflicting or missing information in contract documents. - Failure to give the contractor possession of the site.
Failure to give the contractor possession of the site.
Irrespective of who is at fault, such delays may have a critical financial impact on the project. When they occur, they represent a deviation from the planned programme of work and the contractor may be able to seek a time extension to compensate for the delay. In this case, they can submit a claim to the client outlining the cause and reasons for the delay. The client (or an agent acting on behalf of the client) must then evaluate whether the claim is justified and whether the contractor is entitled to compensation. Analysing who is at fault for the delay is a highly complex process and one which may lead to disputes.
Delay analysis can be undertaken -
Prospectively: Predicting what effect the delay will have on the projects progress, prospective analysis can be used before and after the effect of the delay has occurred.
Retrospectively: Retrospective techniques evaluate the effect that the delay will have on the project but they can only be applied once the works have been completed.
Contemporaneously: During the delay. - The Delay and Disruption Protocol of The Society of Construction Law sets out six methods of delay analysis:
The Delay and Disruption Protocol of The Society of Construction Law sets out six methods of delay analysis:
Impacted As-Planned Analysis. - Time Impact Analysis.
Time Impact Analysis. - Time Slice Windows Analysis.
Time Slice Windows Analysis. - As-Planned versus As-Built Windows Analysis.
As-Planned versus As-Built Windows Analysis. - Retrospective Longest Path Analysis.
Retrospective Longest Path Analysis. - Collapsed As-Built Analysis.
Collapsed As-Built Analysis. -
Introduction - Contracting is the activity of constructing a building (or some other type of built asset) in accordance with a pre-agreed set of requirements, regardless of whether these are verbal or expressed as drawings, specifications and formal contracts.
Contracting is the activity of constructing a building (or some other type of built asset) in accordance with a pre-agreed set of requirements, regardless of whether these are verbal or expressed as drawings, specifications and formal contracts.
An individual or company that contracts in this way is described as a contractor, but may also be called a general contractor, main contractor, building contractor and so on. Irrespective of the name, the activities they undertake will go under the umbrella term contracting. The term contracting derives from the fact that there is usually a contract involved in the process, particularly for large projects; the builder contracts to fulfilling a set of tasks to the satisfaction of the client.
For domestic and other small jobs, the term builder or housebuilder is more often used and, in such cases, it is possible (although inadvisable) that there may not be a formal written contract other than a specification of what is to be carried out or a verbal agreement.
What contracting may involve - Depending on the type of procurement route that is being followed, contracting in the construction sense can involve the following:
Depending on the type of procurement route that is being followed, contracting in the construction sense can involve the following:
Being answerable to a client, or else to the clients representative (such as an architect or engineer);
Performing the role of general manager of a construction project;
Responsibility for the completion and overall coordination of the project;
Responsibility for providing the materials, labour and equipment necessary for constructing the project;
Appointing sub-contractors where necessary and being responsible for their work;
Responsibility for on-site health and safety; - Providing advise to the design team at an early stage of the design process (early contractor involvement (ECI)). Sometimes the contractor may have responsibility for undertaking design activities for some or all of the project.
Providing advise to the design team at an early stage of the design process (early contractor involvement (ECI)). Sometimes the contractor may have responsibility for undertaking design activities for some or all of the project.
Obtaining relevant permissions; - Providing temporary utilities on site;
Providing temporary utilities on site; - Securing the site;
Securing the site; - Managing site personnel;
Managing site personnel; - Construction waste disposal and recycling;
Construction waste disposal and recycling; - Monitoring schedules and cash-flows;
Monitoring schedules and cash-flows; - Keeping accurate records.
Keeping accurate records. -
Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear.
Compression is a force that pushes the particles of a material closer together. For example, when a column supports a load, it is under compression and its height shortens, albeit often imperceivably. The opposite is tensile force which tends to elongate a material.
All materials can, to a certain degree, withstand compressive forces before they fail and it is at this point that compressive strength is measured. Therefore, the compressive strength of a material is usually stated as the maximum compression that the material can stand before failure.
Materials which can resist high, applied compressive forces before failure are said to have high compressive strengths.
Some materials are better than others at withstanding compression before failure occurs. Steel can withstand relatively high compressive forces. Other materials, such as concrete and ceramics, typically show much higher compressive strengths than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation.
Measuring compressive strength - It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a 5,404 ton force.
It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a 5,404 ton force.
In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.
A compressive force is applied to the specimen gradually by the testing mechanism. Measuring the compressive strength using this method requires:
The cross-sectional area of one of the cubes faces, top or bottom (they should be identical), and
The compressive force applied at the time of failure (defined as permanent deformation - ie an inability to assume its former shape once the compressive force is removed).
Once these measurements are available, the compressive strength (C or c) can be calculated as:
C = F/A - where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied. It can be expressed in terms of N/m or Pascals (where 1 Pascal (Pa) = 1 N/m).
where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied. It can be expressed in terms of N/m or Pascals (where 1 Pascal (Pa) = 1 N/m).
It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.
Land banking (or landbanking) is the practice of buying undeveloped land purely as an investment, with no specific plans for its development.
Owners wait for the value of the land to increase, or obtain planning permission to develop the land, and then sell it at a profit, sometimes having broken it into smaller parcels of land. Land is seen as an attractive investment as it is a finite resource, historically it has increased significantly in value, it requires little looking after and cannot be lost.
Land owners can wait many years before selling the land, during which time it will often remain empty, even if it is a developable site and there is a demand for property in the area. This can create blighted sites in key areas of communities that sit vacant for years, having a negative impact on the area and preventing other developments from taking place.
In cities such as London, the rapid increase in the value of land can make land banking a lucrative investment, however, by tying up sites, it can also prevent the demand for property from being satisfied, a demand which is the key cause of the increase in value of the investment.
Land banking can also refer to sites for which planning permission has been granted, but where no construction work has begun, or where minimal construction has been undertaken to satisfy planning requirements that construction should start within 3 years of permission being granted. However, these may simply be stalled sites, where finances are not available to continue the works.
In August 2013, the Local Government Association (LGA) reported that despite the urgent need for new housing, there were 400,000 homes with planning permission that had not been built (although these figures were disputed by Planning Minister Nick Boles).
The charge of landbanking is often directed at property developers. In particular there is a belief that developers regulate the supply of land in order to artificially inflate prices. In 2014, then housing spokesperson for the Liberal Democrats Stephen Knight said, "developers can get away with digging a hole in the ground weeks before their permission is due to expire in order to keep their planning consent alive, with no intention of actually carrying out full development for years to come."
However, a 2012 report for the Mayor of London, Barriers to housing delivery, what are the market-perceived barriers to residential development in London? found that 45% of housing planning permissions were not built because the owners were not developers at all. Instead, they were owner-occupiers, historic land owners, the government and investment funds. In contrast, property developers generally wanted to build as soon as possible. Similarly, a report published in May 2014 by the Home Builders Federation (HBF), Permissions to land debunking the land banking myth suggested that only 4% of the land owned by Britains larger home builders had an implementable planning permission but had not started on site.
Stewart Baseley, Executive Chairman of the Home Builders Federation said, When you look beyond the rhetoric and the lazy accusations, the facts are quite clear: house builders do not hoard land or landbank unnecessarily.
Proposals intended to combat land banking include the introduction of use it or lose it powers allowing planning authorities to pressure owners to implement permissions more quickly. Alternatively, an annual land value tax could be introduced on all land other than owner-occupied properties to increase the incentive to put land to use.
The Financial Conduct Authority (FCA) identify land banking as a potential scam investment scheme, whereby land is purchased, broken up into small plots and then sold to individuals, sometimes from outside the UK, looking to cash in on the property boom. However, plots are often sold at very high prices, with the suggestion that they can be developed and good returns achieved, even though the land in question actually has no possibility of being developed.
The FCA state, Land banking companies divide land into smaller plots to sell it to investors on the basis that once it is available for development it will soar in value. However, the land is often in areas of natural beauty or historical interest, with little chance of it being built on.
In June 2015, eight men were been convicted for running a 4.3 million land banking investment scheme, following an investigation by the FCA.
In July 2017, a report published by housing charity Shelter suggested that in the previous five years, one third of the houses that had been granted planning permission were not actually built.
In October 2017, The Role of Land Pipelines in the UK Housebuilding Process, a report commissioned by Barratt Developments, suggested that housebuilders land banks were reasonable'.
Introduction - In a pipe, sewer, channel or tunnel, the invert is the lowest point upon which water can flow on the inside. If circular in shape, the invert is the lowest point on the inner circle if looking at a section of the construction. The invert may be considered the 'floor level' of the vessel in question.
In a pipe, sewer, channel or tunnel, the invert is the lowest point upon which water can flow on the inside. If circular in shape, the invert is the lowest point on the inner circle if looking at a section of the construction. The invert may be considered the 'floor level' of the vessel in question.
In a tunnel constructed by drill and blast or by NATM (New Austrian Tunnelling Method), the invert will vary according to the stage of the construction: the invert will always be the lowest point inside that has been excavated at that point in time. This will become lower as the excavation proceeds, with the final invert level being that of the complete tunnel.
Also, a tunnel being constructed using NATM (sometimes called 'sequential excavation') may have two or three varying inverts as excavation of the centre and sides of the tunnel may be at different stages.
An invert will typically be laid to a gradient, particularly if it is to convey liquids, such as in a pipe or sewer. The level of the gradient will therefore vary according to the position of the invert along the flow.
The invert level is usually given as a distance to some fixed point. In tunnel construction, invert level may be cited as 10m above tunnel datum (ATD) where the tunnel datum (based on an ordnance datum) is set at a particular level for the entire project. Alternatively, a survey of a property for a preliminary design may record the varying invert levels of the drainage system beneath the building.
In contrast, the crown of the tunnel or pipe is that point located on the top external surface that is directly above the invert. One way to calculate the crown position is by adding (or subtracting) the internal diameter and the materials thickness to (or from) the invert level.
For example, if a 10m-internal diameter tunnel of circular-section with uniform 500mm thickness and an invert level of 16m below ground level, the crown level would be established by subtracting from the invert level the internal diameter (10m) plus subtracting the material thickness, which is equivalent to: 16m 10m 0.5m = 5.5m.
So, the crown datum level is at 5.5m below ground.
Sometimes it may be necessary to reverse this calculation when the crown is known and the invert level is not known.
Introduction - Infrastructure is the term used to describe the interconnected organisational structures that underpin society and enable it to function effectively.
Infrastructure is the term used to describe the interconnected organisational structures that underpin society and enable it to function effectively.
In its physical sense, infrastructure generally relates to the assets necessary to facilitate the flow of supplies required by society, sometimes referred to as 'hard' infrastructure.
Infrastructure UK (now the Infrastructure and Projects Authority) described the infrastructure sectors as:
Energy. - Transport.
Transport. - Waste.
Waste. - Flood.
Flood. - Science.
Science. - Water.
Water. - Telecoms.
Telecoms. - These assets generally require both physical networks and control systems.
These assets generally require both physical networks and control systems.
'Soft' infrastructure can also be include built assets, such as hospitals and schools, that are central to the operation of society. However, more commonly it refers to organisational mechanisms, such as government, legislation the emergency services and so on.
Civil engineers are the profession most commonly associated the provision of hard infrastructure. Civil engineers design, construct, maintain and improve the physical environment, including; bridges, tunnels, roads, railways, canals, dams, buildings, flood and coastal defences, airports and other large structures.
Sound is transmitted in buildings by both air-borne sound and structure-borne sound.
Impact sound (or impact noise) is a form of structure-borne sound that occurs when an object impacts on another, resulting in the generation and transmission of sound. The structural vibration caused by the impact results in sound being radiated from an adjacent vibrating surface. NB structure-borne sound may also be generated by vibrating sources rather than impact sources.
A typical example of an impact sound is footsteps on a floor resulting in sound being transmitted through the floor construction and heard in the space below. Impact sound can travel through solid structures and through cavities.
Impact sound can be a form of noise nuisance, particularly in dwellings, and can contribute to health problems, such as:
Tension or anxiety. - Decreased performance.
Decreased performance. - Reduced productivity.
Reduced productivity. - Eardrum damage or hearing difficulties.
Eardrum damage or hearing difficulties. - Increased blood pressure or stress levels.
Increased blood pressure or stress levels. - Psychological damage.
Psychological damage. - The occurrence of impact sound is dependent on a range of factors, including:
The occurrence of impact sound is dependent on a range of factors, including:
The force of impact. - The characteristics of the surface that is impacted upon.
The characteristics of the surface that is impacted upon.
The characteristics of the structure through which the vibration transmits.
The characteristics of the radiating surface. - Impact sound can be prevented or reduced by:
Impact sound can be prevented or reduced by:
Carpets and pads soft carpets and thick pad cushions can be particularly effective at reducing middle to high level frequencies, although they are less effective at isolating low frequency sound. It is important to consider whether carpets or pads might be removed in the future.
Resilient underlay can have a similar effect to carpets and pads. Generally, they are made from recycled rubber, rigid fibreglass, foam or other such materials. They absorb, or isolate impact energy and can be effective in minimising impact sound at middle to high level frequencies. If the underlay has significant mass, it may also provide sound insulation from air-borne sound.
Resilient mounts hanging resilient mounts, sound clips or spring ceiling hangers can reduce the transmission of impact sound.
Soundproofing compounds applying sound proofing layers can be effective in reducing impact sound. Typically the compound is applied between two rigid materials, such as subflooring. The compound dissipates the vibrations caused by sound waves as they move through the structure, and can reduce sound at all frequencies.
A suspended ceiling system or raised floors can be used to improve impact sound insulation.
Building Regulations Approved Document E - 'Resistance to the passage of sound' sets minimum standards for impact sound insulation.
Impact sound transmission is typically measured in-situ with a tapping machine which uses steel-faced hammers to strike a test surface and generate sound in an adjacent space which can be recorded or monitored. This is useful only in giving an indication of the likely level of impact sound as it does not accurately represent the variety of impacts that might be experienced in practice.
The term hydrogeology refers to the nature, distribution and movement of groundwater in soils and rocks, including in aquifers.
Where the term 'groundwater' refers to all water which is below the surface of the ground and within the permanently saturated zone. A groundwater body is a distinct volume of groundwater within an aquifer.
The word huburb refers to a former suburb that has developed into a hub in its own right, that is, it provides a transport hub for trains, busses or trams, it is a cultural hub with cinemas galleries or theatres, it is a shopping hub and so on.
A suburb is an area on the edge of a large town or city, typically residential in character. Whilst often attractive to the middle classes, suburbs have been criticised for being bland, sprawling and ill-defined, with insufficient density to support the social or commercial infrastructure necessary to create an effective community or urban hub.
Advocates of densification argue that the denser a city, the more sustainable it is, since dense cities use less energy per person than suburban or rural areas where people are spread over a wider distance and so travel more often and further.
A garden is an enclosed area of, typically external, land that is cultivated with natural and ornamental features.
The most common type of garden is a residential garden, which a domestic building. However, there are many different variations, including:
Winter garden: A garden maintained throughout winter.
Landscape garden: A large-scale landscape. - Zen garden: A small-scale idealised landscape with plants usually kept to a minimum.
Zen garden: A small-scale idealised landscape with plants usually kept to a minimum.
French formal garden: Based on symmetry and the idea of imposing order on nature.
Tropical garden: Tropical conditions are created to enable the cultivation of tropical plants.
Roof garden: A garden located on the roof of a building.
Kitchen garden: and ornamental vegetable garden. - English garden: A style of landscape garden that idealises nature.
English garden: A style of landscape garden that idealises nature.
While residential gardens are often maintained by the property owner, professional gardeners, horticulturists and landscape architects are often involved in the design of larger-scale or specialist gardens.
Garden design involves drawing up plans for laying out and planting different landscapes, and this will largely be determined by the purpose for which the garden is intended. Some gardens are purely for aesthetic or ornamental purposes, while others can be more functional growing food and other crops, and so on.
Other considerations for the planting of gardens include:
The location, climate and exposure. - The soil type.
The soil type. - Topography.
Topography. - Means of access.
Means of access. - The potential for pests to damage the garden.
The potential for pests to damage the garden.
The horticultural requirements. - The appearance of the plants season-by-season.
The appearance of the plants season-by-season. - The typical lifespan of the plants.
The typical lifespan of the plants. - The growth habits of the plants their size, rate of growth, and so on.
The growth habits of the plants their size, rate of growth, and so on.
The maintenance needs of the garden. - The elements of hard landscape and other features that will be included.
The elements of hard landscape and other features that will be included.
How the garden will be used. - How the garden will connect and/or interact with the building or other structures.
How the garden will connect and/or interact with the building or other structures.
Privacy and security. - Budget and time constraints.
Budget and time constraints. - The natural elements included in a garden typically comprise:
The natural elements included in a garden typically comprise:
Flora (trees, shrubs, lawns, etc.).
Fauna (anthropods, birds, etc.).
Soil, compost, mulch, etc. - Water (streams, ponds, etc.).
Water (streams, ponds, etc.).
For more information, see soft landscape. -
Some of the hard landscape (or hardscape) elements that can be part of a garden include:
Paths. - Patios.
Patios. - Decking.
Decking. - Sculptures.
Sculptures. - Fencing and walls.
Fencing and walls. - Drainage systems.
Drainage systems. - Irrigation systems (e.g. sprinklers).
Irrigation systems (e.g. sprinklers).
Lights. - Structures (e.g. sheds, gazebos, pergolas, follies, greenhouses).
Structures (e.g. sheds, gazebos, pergolas, follies, greenhouses).
Water features (e.g. fountains, ponds, creeks, waterfalls).
Trellises. - NB A Guide To Climate Change Impacts, On Scotlands Historic Environment, published by Historic Environment Scotland in October 2019, defines gardens and designed landscapes as: A category of asset encompassing botanic gardens, parks, landscapes laid out for artistic effect and a range of features within these areas.
NB A Guide To Climate Change Impacts, On Scotlands Historic Environment, published by Historic Environment Scotland in October 2019, defines gardens and designed landscapes as: A category of asset encompassing botanic gardens, parks, landscapes laid out for artistic effect and a range of features within these areas.
For more information, see hard landscape. -
The term ground level, or ground floor, is used to refer to the level of a building that is at ground / street level. The term storey tends to refer to all levels of a building above the ground level.
It can also refer to the level of ground that has not be built on. The level of the ground before any excavation or filling has been carried out is referred to as the natural ground level, whereas finished ground level is when it has been finished with paving stones, asphalt, landscaped grass, and so on.
In very broad terms, an 'owner' is a person or organisation who has the rightful title to something such as property, i.e. the property belongs to them.
A homeowner is a person who owns a home, whether an apartment or house. They may have fully paid for the home and own it outright, or they may still owe money for it: an individual who has a mortgage on a property is still regarded as the homeowner even if the mortgage has many years to run and much money is owed.
Homeowners do not have to reside in their properties: landlords are still homeowners even if they rent out their properties to other people.
Homeowners who have acquired their first home (whether outright or through a mortgage) are usually said to have taken their first step on the housing ladder. They are often referred to as 'first-time buyers', and a number of government schemes have been introduced in recent years to encourage and support their entry into the housing market.
It is also possible to be a homeowner jointly with other people (such as a partner) or through shared ownership schemes provided by housing associations, although this may be viewed by some as part-home ownership. Such schemes typically involve purchasing a share of a property (typically between 25%-75%). A mortgage is required for the share that is purchased, and rent is paid on the remainder.
The housing policies of the conservative Thatcher government of the 1980s were designed to increase home ownership throughout the UK and to decrease the number of households in rented accommodation. Owning your home was regarded by many conservatives as almost a basic right. Policies were therefore implemented to bring this about, such as right to buy where council tenants were given the right to buy their homes from the local authority often at prices that were well below market values.
More recently, the governments help to buy scheme is aimed at enabling first-time buyers get on the property ladder and become homeowners.
The term housebuilder (or home builder) is commonly used to refer to a building contractor that specialising in building houses. 'Housebuilder' may sometimes be shortened to 'builder', differentiated from a 'contractor' who tends to construct buildings other than houses.
Unlike contractors, housebuilders often directly employ all the construction workers necessary to compete the houses, rather than subcontracting the works to specialist trades. This is because housebuilding is a relatively repetitive process, for which the workforce required is reasonably predictable and so direct employment of the workforce does not become a problem as the builder moves from one project to another.
A small housebuilder is a company that builds fewer than 100 homes per year.
In 2017, the top 10 housebuilders in the UK were:
Barratt Developments - Taylor Wimpey
Taylor Wimpey - Persimmon
Persimmon - Berkeley
Berkeley - Bellway
Bellway - Redrow
Redrow - Bovis Homes
Bovis Homes - Crest Nicholson
Crest Nicholson - Mears
Mears - Bloor Homes
Bloor Homes - Ref https://www.building.co.uk/data/top-20-housebuilders-2017/5088919.article
Ref https://www.building.co.uk/data/top-20-housebuilders-2017/5088919.article -
Housebuilders are sometimes accused, particularly in times of housing shortages, of not building sufficient houses and sometimes engaging in land banking; regulating the supply of land that is developed in order to artificially inflate prices. This is something that housebuilders themselves strenuously deny. See Landbanking for more information.
A housing start, also known as a new start, is an economic indicator used to assess the number of new residential construction projects that have begun over a certain period (such as a month, a quarter or a year). The figures for new housing starts can provide an indicator for how the economy is performing over a given period of time. The National House Building Council reported that builders registered plans to start 160,606 new homes in 2018. For more information see: What is a housing start?
The picture is complicated by that fact that not all homes are houses, and the broader term 'residential', or 'dwelling' may be a better representation of the number of homes than just housing. See Residential definition for more information.
The Home Builders Federation (HBF) is the representative body of the home building industry in England and Wales.
The National House Building Council (NHBC) independently regulates the new homes industry. It is a non-profit distributing company limited by guarantee and is now the UKs leading standard-setting body and provider of insurance and warranties for newly-built homes. It is also the largest single approved inspector for the building regulations.
Housebuilders have been criticised for producing repetitive buildings with little character, and in recent years they have come under fire for a poor quality of workmanship. For more information see: Housing defects.
Insurer (sometimes called the insurance provider, insurance company or underwriter) refers to a company that provides various types of insurance policy to indemnify individuals, groups, organisations, government agencies and other bodies. Such insurance policies can provide cover and may pay out in cases of ill health, job loss, accidents, theft, property damage, professional liability and other instances where individuals and companies may face heavy losses if uninsured.
The insurance policy is a sort of contract stipulating the conditions under which the insurer promises to compensate the insured (those who have purchased a policy) against a stated loss or losses.
For more information see: Insurance. -
The insurer is not the same as the insurance broker or agent. The latter advises those seeking to buy insurance, arranges cover and passes on the premium (plus commission for their effort) to the insurer.
Recent times have seen many small, high street brokers put out of business, as insurance can now often be arranged directly with insurers over the internet.
Inflatable buildings are constructed using two layers of membrane connected together to form inflatable 'cushions'. Membranes are usually less than 1 mm thick, and air is used to pressurise the cavity between them to form a 'rigid', structurally stable element, capable of spanning large distances.
Inflatable buildings differ from air-supported buildings, which are formed by a single-layer membrane that is supported by pressurisation of the whole interior of the building. An air-supported building prevents air from being lost when access points are opened by using airlocks, which maintain the level of air pressure inside the occupied space. Inflatable buildings have a lower power requirement than inflatable buildings as they require a lower volume of pressurised air.
Inflatable buildings are typically used for warehouses and other storage facilities, sports facilities, stadia, shopping centres and so on. Since the amount of material used for inflatable buildings is relatively low, they can be portable, with the air allowed to escape before the membrane is packed down to a small volume.
Inflatable structures (or inflatables) can also be used to create specific components such as; escape slides, mattresses, swimming and paddling pools, play slides, bouncy castles, and so on.
Legal requirements apply to the supply, hire and use of inflatable play equipment for commercial purposes, but not to private, domestic buyers and users. Inflatables can be dangerous in terms of user injuries as well as being unsuitable in high winds if inadequately secured.
Inflatables should be checked before buying or hiring for an event to ensure they comply with BS EN 14960. A label should provide information about when the inflatable was made, how many people can use it and their maximum heights. Once the inflatable is fully inflated, it should be inspected prior to use to check that the site is suitable, that the anchorages are secure, and the internal air pressure provides a firm footing.
Investment property is real estate that is used for the purposes of investment, with the aim being to earn a financial return. This return can be earned either through rental income, the capital gain on future resale of the property or, as is typical, both.
A common type of investment property is an apartment building or rental house, which the owner uses to gain ongoing rental income from tenants rather than using a primary residence.
Investment property can be either long-term, whereby the owner generates capital gains as property values increase over time, or short-term, which is known as 'flipping' - real estate bought, redeveloped or renovated, and sold at a profit. If an investment property is sold for a higher price than it was purchased for, then it will be subject to capital gains tax.
The value of an investment property can be influenced considerably by the way it is used, and property investors typically investigate the most profitable use of a property prior to beginning redevelopment. For example, they will assess whether a piece of real estate near a busy urban high street will have a higher rate of return as a residential or commercial building.
Like all investments, property carries some degree of risk. Typically there is less risk if the property is high quality and in a 'prime' location, although the risk still remains that an investor may pay too, the market will drop, the cost of redevelopment will go up, there are delays, permissions are not received, purchasers do not come forwards and so on. Lower quality property in less a prime location may present more risk but can demonstrate high capital growth, in particular if the area experiences a period of gentrification.
Some of the unique characteristics of investment property include:
Unlike stocks and shares, property is not a standardised investment. No two properties are the same.
Property is not a pre-packaged investment - owners have to manage the property.
Property can often be improved by active management, such as refurbishment, renovation, and so on.
Property can be created by acquiring land or rights to land.
Property can be traded at auction or sales, and purchases can be negotiated by estate agents and surveyors, but there is no single market.
The physical structure of a building may require further investment, but the land on which it stands will not.
The property investor can have different forms of title from owning the property as a freehold, a long leasehold, short leasehold, and so on.
Introduction - A gully is a type of land formation (such as a ravine, ditch or trench) typically caused by erosion. In Scotland and Northern England, a gully is also a type of large knife that is sometimes used in the kitchen or farmhouse. Despite having nautical associations, a gully knife is not meant to be a weapon, although it may have been used to cut sails.
A gully is a type of land formation (such as a ravine, ditch or trench) typically caused by erosion. In Scotland and Northern England, a gully is also a type of large knife that is sometimes used in the kitchen or farmhouse. Despite having nautical associations, a gully knife is not meant to be a weapon, although it may have been used to cut sails.
The term gully is not the same as gulley, which is a fitting with a chamber which is designed to collect rainwater, wastewater and groundwater, conveying it to an underground surface-water sewer. Confusingly however this is often spelt 'gully'. For more information, see Gulley.
One of the earliest appearances of the term gully was in the 1600s. The word has French origins and is associated with the term goule, which can be interpreted to mean mouth.
How gullies form - Gullies are generally caused by running water which creates a ditch or valley in the landscape.
Gullies are generally caused by running water which creates a ditch or valley in the landscape.
Gully erosion commonly occurs on hillsides when vegetation is removed by processes such as overgrazing, fires, storms and so on. Human modifications to the landscape can also make hillsides susceptible to gully erosion. Deforestation, site development, hydraulic mining and other types of human activity can make it easier for loose soil to be carried away by flowing water - resulting in gully erosion.
Sometimes sinkholes can be associated with gully erosion, since both are almost always the result of a concentrated flow of water. For example, a sinkhole may trigger the formation of a new gully after a pipe or roadway collapse, or it may extend an existing gully.
Problems with gullies - Regardless of their origins, gullies will generally grow once they have formed and will continue to grow unless erosion issues are addressed.
Regardless of their origins, gullies will generally grow once they have formed and will continue to grow unless erosion issues are addressed.
The production and transportation of sediment that is caused by the creation of a gully may have a negative effect on downstream ecosystems. It can even clog or contaminate waterways.
As well as damage to the landscape, the development of gullies can lead to agricultural issues around farm operations and can also cause damage to private property.
Gas holders are typically Victorian-era containers used in urban areas to store large volumes of gas, usually from nearby gasworks. Natural, or town, gas would be stored near atmospheric pressure at ambient temperatures. The container would be moveable and rise and fall with the quantity of stored gas.
Now predominantly unused, with many having, or planning to be, dismantled, they have been referred to as the sentinels of the Industrial age', with their iron lattice frames becoming an iconic symbol of Victorian Britain. One of the most famous gas holders overlooks the Oval cricket ground in South London (see image above).
Gas holders are also referred to as gasometers. This was a term coined by William Murdoch, the inventor of gas lighting, although it caused consternation among some of his peers who complained that a gas holder was a container and not a meter. However, the name fell into general use as the structures spread across the country during the 19th century.
The telescopic gas holder was invented in 1824, with the first example built in Leeds, allowing for much more storage. This early type of gas holder consisted of a number of vessels situated one inside the other. When the inner vessel was fully extended, the next outer vessel would rise.
In 1890, William Gadd invented the spirally-guided gas holder which used spiral rails instead of external columns or guide frames.
Gas holders became permanent fixtures across the country by the early-20th century, capable of storing up to 2 million cubic feet of gas enough to supply 2,400 homes.
However, development in gas pipe technology and the discovery of natural gas in the North Sea in 1965, led to a decline in reliance on gas holders. Instead of town gas being used, the gas from the North Sea was piped under high pressure. The role of gas holders became one of providing extra capacity when needed by the gas network, although as the pipelines became more and more effective, this role also soon dwindled.
By the 1990s, most local gas networks were able to function at full capacity without using gas holders, leading to a decision in 1999 to start demolishing them. National Grid, who own most of the gas holders, continue to oversee dismantling in order to sell off the now-valuable land upon which they sat.
The dismantling process is complicated. One crane is used to lift a worker who uses a plasma cutter to sever sections of the iron girders, while a second crane holds the sections and lowers them once they have been sheared off.
Northern Gas Networks have trialed sludge solidification, a process in which the solids that have accumulated at the bottom of the holding tank are buried with the base itself. The idea is that this is a safer and more cost-effective method than removal by tanker, and also helps prevent soil contamination.
There is hope for some of the remaining gas holders though, as there are continued protests from local communities when plans are made to dismantle them. Various architectural firms have sought to incorporate the structures into their designs. For example, Gasholder No. 8 has been converted into a park with a circular lawn and polished steel pavilion as part of the redevelopment of Kings Cross.
The term gentrification refers to changes that occur over time as a direct or indirect result of people on higher incomes purchasing or renting property in low income or working class areas.
In an urban context, gentrification is associated with movement and can be viewed positively, in that it drives investment and economic prosperity to an area; and negatively, in that there is the perception that the traditional character and culture of an area becomes diluted and gradually rendered obsolete.
The term derives from the word gentry which historically referred to people with wealth, although it originates from the Old French genterise meaning of gentle birth which became anglicised as gentleman. The term itself was coined by the sociologist Ruth Glass in 1964 in response to the influx of middle-class people to the cities which she saw as displacing lower-class residents.
Urban theorists broadly agree in the belief that before an area becomes gentrified it must experience a period of disinvestment and decline. During this period, median income levels decline, infrastructure and buildings fall into disrepair, and businesses relocate elsewhere. These are often described as urban wastelands.
At some point in this period of decline, the area starts to attract people who are predominantly young, educated, artistically-minded, and with some level of disposable income. Artist communities, exhibition and performance spaces, underground music venues, and independent shops begin to appear in abandoned industrial spaces, as the area develops a reputation for being alternative, edgy and bohemian, reflecting the lifestyles and tastes of those who move there.
Where once an area may have been viewed as unwelcoming or dangerous, it slowly becomes a more attractive prospect to real estate developers and wealthier young people who may be moving into a city from the suburbs or elsewhere. Responding to the interest, developers may seek to buy and regenerate old buildings, creating new apartments which gradually push property prices higher. As this happens, the reputation of the area as being alternative and interesting starts to diminish; independent businesses are replaced by chain stores, the unique character of the area becomes more homogenised.
The firmest indication of gentrification is an increase in property prices, rents and taxes in a particular district. This usually correlates with the increased incomes of people arriving in the area. As a result, those on lower incomes are priced out of the area, and it slowly becomes economically homogeneous.
Political initiatives often have the effect of promoting gentrification, by introducing deferred taxes for real estate companies, mortgage incentives for first-time buyers, and financial incentives for the owners of rental housing or other buildings that require renovation.
One of the main advantages of gentrification is that old industrial buildings are renovated and redeveloped which can make the area more visually appealing and reduce crime rates. It can also reduce vacancy rates and encourage further development and business investment, which can increase employment opportunities.
The rise in property values cause taxes based on values to increase; but this can result in owners unable to pay the taxes being forced to sell their property and move to a cheaper community.
Rent controls are seen as one potential action that can combat gentrification pricing out local residents. However, controls can be counter-productive, and cities such as New York have found that they reduce the number of available rental properties, or subsidise wealthy inhabitants. Other measures are similarly controversial, such as demands that new builds provide socially-affordable housing provision, which leads to complaints that such accommodation is often of poor quality or sold by developers to overseas investors, leaving lucrative properties empty.
Examples of urban gentrification that some consider to have had a net-positive effect include the areas of Shoreditch and Hackney in East London; Brixton in South London; Brooklyn in New York; and Kreuzberg in Berlin.
The purpose of an Environmental Impact Assessment (EIA) is to ensure that the environmental effects of a proposed development are properly considered. An EIA provides the local planning authority with better information about certain types of projects, enabling them to make a more informed decision about whether permission should be granted and to allow imposition of more appropriate conditions and obligations to mitigate possible negative impacts.
The Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 2011 sets out a requirement to carry out an EIA as part of the planning application process for certain projects (generally those which are large or environmentally complex).
For more information, see Environmental impact. -
Carrying out an EIA can involve a considerable amount of work, can cause significant delays and incur additional costs to a project. It may therefore be advisable to enter into early consultation with the local planning authority to determine whether an EIA will be required, and if so, what it should contain and what methodology should be used to carry out the necessary assessments.
If an applicant is uncertain about whether an EIA is required, they can ask the local planning authority for a decision called a 'screening opinion' (or screening decision). They can also ask the local planning authority for advice about the required scope of the EIA; this is called a 'scoping opinion' (or scoping decision). If the applicant disagrees with these opinions, they can appeal to the Secretary of State who will then make a direction.
EIAs are required for developments described in Schedule 1 and Schedule 2 of The Town and Country Planning (environmental impact assessment) (England and Wales) Regulations. This includes a wide variety of projects such as:
Power stations - Refineries
Refineries - Certain industrial processes
Certain industrial processes - Certain transport projects
Certain transport projects - Dams
Dams - Pipelines
Pipelines - Airports
Airports - Major projects (above certain thresholds set out in Schedule 2)
Major projects (above certain thresholds set out in Schedule 2)
Developments in sensitive or vulnerable locations (thresholds do not apply in sensitive locations such as national parks or national nature reserves where every project must be screened for environmental impact assessment).
Unusually complex projects that may have adverse environmental effects.
An Environmental Statement (usually prepared by the developer) summarises the findings of the EIA process and is used primarily to inform decision makers regarding the environmental implications of the development. In addition, it should provide appropriate information for statutory consultees, other interested organisations and members of the public and should provide a basis for consultation.
An Environmental Statement may contain: -
A description of the proposed development and its use.
An estimate of the likely residues and emissions resulting from the construction and operation of the development (water, air and soil pollution, noise, vibration, light, heat, radiation, etc.).
An assessment of how the development complies with planning policy.
An assessment of environmental opportunities and constraints. - An assessment of appropriate alternatives. This may include an assessment of possible alternative sites, so it is important that this is done during the very early stages of a project - not as a process of post-rationalisation after the client has already selected a site.
An assessment of appropriate alternatives. This may include an assessment of possible alternative sites, so it is important that this is done during the very early stages of a project - not as a process of post-rationalisation after the client has already selected a site.
An assessment of the likely impacts of the development.
See Environmental Statement for more information. -
On 22 August 2017, the Crown Commercial Service (CCS) released details about their new framework, which they claim could significantly reduce the cost of managing public sector estates.
The Estates Professional Services framework (RM3816) enables organisations to purchase help in managing their estates and assets through advice, guidance and associated services. This could help reduce property costs, release unwanted property assets, and the identify savings and opportunities for generating income from land and buildings.
The CCS estimates that the framework could save public sector bodies such as local councils, NHS trusts, schools, emergency services and housing associations around 35 million over the next four years. Over the course of the frameworks next four years, CCS expect spending of 430 million, with more than one-third of the businesses supplying the new agreement being SMEs.
For the first time, the framework provides access to vertical real estate suppliers, as well as a managed procurement offering. The framework also has a focus on regional expertise, prompted by more SMEs winning places to supply estates services to the public sector than ever before.
The framework will be structured into 4 lots, with the inclusion on lot 2 of regional panels.
Lot 1 - National. - Lot 2A - East Anglia.
Lot 2A - East Anglia. - Lot 2B - East & West Midlands.
Lot 2B - East & West Midlands. - Lot 2C - London & South East England.
Lot 2C - London & South East England.
Lot 2D - North East England. - Lot 2E - North West England & North Wales.
Lot 2E - North West England & North Wales.
Lot 2F - Northern Ireland. - Lot 2G - Scotland.
Lot 2G - Scotland. - Lot 2H - South Wales & South West England.
Lot 2H - South Wales & South West England.
Lot 3 - Vertical Real Estate. - Lot 4 - Facilities Management and Property Services (Procurement Managed Service).
Lot 4 - Facilities Management and Property Services (Procurement Managed Service).
This new agreement aims to complement the CCSs other property frameworks (Project Management and Full Design Team Services, Facilities Management, and Construction), enabling the provision of a comprehensive property management solution package.
Several definitions have been developed to assess or specify the expected life of buildings, structures or their components from the perspective of different stakeholders.
Functional life refers to the amount of time that an element may be in service before it is rendered obsolete due to changes in functional requirements, such as a change in use.
However, as there is no general legally-agreed definition of functional life, if it is to be included in contract documentation as a performance requirement, it is important that it is carefully defined within those contract documents and that it is consistent with all other requirements in the contract documents.
Other definitions include: -
Design life. - Required life.
Required life. - Technical life.
Technical life. - Economic life.
Economic life. - Service life.
Service life. -
The term furniture refers to moveable objects that are used to support human activities in the built environment. However, it can also be used more widely to refer to fitted objects and equipment.
Furniture tends to be of a craft-based design type that can be functional, decorative, symbolic, ceremonial, and so on. Many different materials are used in the manufacture of furniture, most commonly; timber, metal, plastic, fabrics, leather, and so on.
Furniture is subject to frequent changes in fashion, and tastes for furniture can vary widely from person to person.
Some of the main types of furniture include:
Furniture for sitting: Chairs, stools, sofas, futons, etc.
Furniture for eating or working: Tables, desks, etc.
Furniture for sleeping: Beds, cots, bunks, etc.
Furniture for storage: chests, wardrobes, etc.
Garden furniture: Chairs, tables, etc.
Street furniture: Benches, barriers, street lamps, traffic lights, bollards, etc.
Furniture can be grouped together with other components as 'FF&E' (furniture, fixture and equipment). FF&E might be procured separately to the main construction contract (or elements of them), particularly by clients that already have systems in place for procuring fixed and loose furniture, fittings and equipment; for example, schools, universities, or hospitals. For more information, see Furniture fixtures and equipment FF&E.
Interior designers are often associated with specifying furniture, analysing how a space is to be used and how best it can be planned with the most appropriate objects, considering functionality, aesthetic, space efficiency, circulation requirements, and so on. For more information, see Interior design
The Furniture and Furnishings (Fire Safety) Regulations define requirements for the fire resistance for domestic upholstered furniture, furnishings and other products containing upholstery. These Regulations are enforced by Trading Standards.
A fountain is an architectural feature which involves water and is often used as part of landscaping. A fountain can either pour water into a basin to create a waterfall effect or spray water into the air to create a jet effect. Fountains are often used as decorative features in public spaces and gardens.
Drinking fountains are used to provide drinking water public spaces, and special musical fountains combine lights, music and moving water jets for purposes of entertainment. Splash fountains are often used in public spaces and intended for interaction.
The earliest fountains, in Ancient Rome, were functional and used for providing water for drinking and washing. For a water flow to be consistent it required a source (e.g. reservoir or aqueduct) that was higher than the fountain and so was reliant on gravity.
By the end of the 19th century, fountains had been replaced as the main source of drinking water by domestic plumbing and so became primarily decorative. At around this time, gravity was replaced by mechanical pumps which enabled fountains to recycle water and project it into the air. At the start of the 20th century, fountains began to adopt steam pumps and then later on electric pumps to receive water from the source.
Modern fountains rely on a closed recirculating system to recycle water. An electric pump is used to provide the power to push water through the pipes. The pump is typically submerged in the water reservoir and consists of a spinning impellor to draw water in and force it out by centrifugal force. The most appropriate pumping rate will need to be found as the fountain can splash and waste water if it is set too high and will not circulate at all if it is set too low.
Water is delivered to the fountain head and then sprayed into the air through a nozzle or left to flow outside the fountain. In both cases the water will fall back onto the fountain and drain back into the reservoir. Larger fountains will often be fitted with multiple nozzles and pumps.
A filter known as a media filter, is used to remove particles from the water as it is circulated. It is fitted with its own pump and plumbing to take water from the pool to the filter and back to the pool. The water can be cleaned using treatments such as chlorination or anti-algal methods.
A plant room is provided to store the pumps, filter, electrical switch box and plumbing controls, and this must be well-constructed so as not to leak and create a hazard. Fountains can often use low-voltage lighting, often submerged in the water, which minimises hazards.
Water in a fountain is gradually lost due to evaporation so it must be topped up at certain times, and allowances made to be able to cope with overflow after heavy rain.
Some notable fountains include: -
King Fahds Fountain, Jeddah, Saudi Arabia: Jets water 260 m into the air making it the worlds highest continually-running fountain.
Jet dEau fountain, Geneva, Switzerland: First modern high-shooting fountain, completed in 1951.
Bellagio Hotel & Casino musical fountain, Las Vegas: Famous choreographed fountain with pivoting nozzles which vary the water patterns.
Buckingham Fountain, Chicago: One of the worlds largest fountains, it is designed in a Rococo wedding cake-style.
Trevi fountain, Rome, Italy: Large Baroque fountain completed in 1762.
The term 'eyesore' is commonly used to describe a building, structure or other feature of the environment that is ugly or unsightly. This is largely a subjective assessment, but common characteristics that can contribute to being labelled an eyesore include:
Dilapidation. - Graffiti.
Graffiti. - Litter.
Litter. - Pollution.
Pollution. - Contamination.
Contamination. - Advertising, signage and flyposting.
Advertising, signage and flyposting. - Transmission towers and other 'industrial' structures.
Transmission towers and other 'industrial' structures.
Brownfield sites. - Stalled construction sites.
Stalled construction sites. - Inappropriate development that is out of character with its context.
Inappropriate development that is out of character with its context.
Eyesores can blight local areas, affecting moral, inward investment and property prices, and encouraging anti-social behaviour such as fly tipping and graffiti that make the problem worse. Local authorities and national governments sometimes seek to improve or remove eyesores, sometimes as part of a wider gentrification strategy. This may take place for example if there is a high-profile project requiring a large amount of investment in an area, such as the Olympic Games.
The Carbuncle Cup is an annual architectural prize awarded by the magazine Building Design. The 'winner' is 'the ugliest building in the United Kingdom completed in the last 12 months.' The award is usually timed to coincide with the prestigious Sterling Prize, as a light-hearted way of identifying 'crimes against architecture'. The name is derived from Prince Charles' oft-quoted criticism of the proposed extension to the National Gallery in 1984 which he described as a monstrous carbuncle on the face of a much-loved and elegant friend.
However, some projects can be initially regarded as eyesores before being reappraised, such as; the Eiffel Tower, the Golden Gate Bridge, the Pompidou Centre and Lloyds of London.
Gentrification is sometimes considered to have negative consequences as well as positive, destroying the unique character of a place, and driving up prices so that 'locals' have to move out.
Introduction - The term exurb, exurbia or exurbian is a US reference to the residential areas well beyond the suburbs. This term is comparable to the UK term, stockbroker belt.
The term exurb, exurbia or exurbian is a US reference to the residential areas well beyond the suburbs. This term is comparable to the UK term, stockbroker belt.
Residential focus - The residents of these neighbourhoods are often wealthy commuters or exurbanites. These neighbourhoods may also be referred to as commuter towns or bedroom communities.
The residents of these neighbourhoods are often wealthy commuters or exurbanites. These neighbourhoods may also be referred to as commuter towns or bedroom communities.
Exurbs and suburbs are similar in nature. They are dominated by residential properties (and associated services) rather than commercial or industrial facilities. However, there are slight differences between exurbs and suburbs. Suburbs tend to be developed in an area that is near a primary source of employment (such as a major city), while exurbs are more rural and may be separated from the suburbs by green space.
Resurgence of the exurb - The first use of the term exurb goes back to the 1950s. The concept was popularised by Auguste C. Spectorsky in his 1955 book, 'The Exurbanites'.
The first use of the term exurb goes back to the 1950s. The concept was popularised by Auguste C. Spectorsky in his 1955 book, 'The Exurbanites'.
The appeal of the exurbs increased dramatically after 2000 and then dipped until about 2010. In 2019, more millennials were moving to the exurbs, reversing the downward trend of the previous decade.
The attraction of exurbs has several causes, including the need for homes that are affordable, as the cost of city living is beyond reach for some. In addition, the upheaval in the manufacturing sector has resulted in the closure of many large sources of traditional employment. While residents remain in their communities, they may be forced to look for jobs elsewhere in other towns or cities.
Enterprise zones are intended to encourage growth and create new businesses and new jobs by allowing simplified planning procedures and through business rates discounts.
The government originally intended to establish 21 enterprise zones in Local Enterprise Partnerships (LEPs) areas. LEPs are business-led partnerships created to drive sustainable economic growth across local economic areas. LEPs are able to bid for enterprise zones.
Enterprise zones are geographically defined areas, usually 50 to 150 hectares, agreed between the LEP and government. Enterprise zones are created in areas of 'economic opportunity', generally on clean sites, i.e. sites with few existing business occupants.
Enterprise zones benefit from a number of provisions:
A business rate discount of up to 100%, (limited by EU law to a maximum of approximately 55,000 per year) for five years. The government reimburses the local authority the cost of the discount.
Business rates growth for at least 25 years is retained and reinvested locally to support the LEPs priorities.
Simplified planning procedures are adopted. This is generally done through the use of Local Development Orders, which can allow development without the need for planning permission. Local Development Orders can be used to permit any type of development in a particular area, or to permit a specific type of development. Conditions can be attached to the developments. The process of drafting a Local Development Order, carrying out public consultation and notifying the Secretary of State can take as little as two months.
The government provides support, which can include funding, to ensure that 'superfast' broadband is made available throughout the enterprise zone.
The government can make enhanced capital allowances for plant and machinery in areas within enterprise zones where there is a strong focus on manufacturing.
In the 2015 Budget, Chancellor George Osborne suggested that enterprise zones had created over 12,500 jobs and attracted 2bn in private investment, and announced that a number of existing enterprise zones would be expanded and new enterprise zones created in Blackpool and Plymouth. (Ref. Gov.uk Budget 2015 documents.)
In March 2016, Communities Secretary Greg Clark announced that Englands 39 Local Enterprise Partnerships would be able to apply for a share of 1.8 billion to support projects in their areas. (Ref. gov.uk.)
However, a report by the Comptroller and Auditor General of the National Audit Office, also published in March 2016, questioned the transparency of LEPs and recommended clarification about how they fit with other bodies to which power and spending have been devolved, and suggested that specific quantifiable objectives and performance indicators were set out for the success of Growth Deals.
Introduction - Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
Orthographic projection is a technique for drawing a three dimensional object in two dimensions, by projecting its surfaces into a two dimensional representation, where the projection lines are orthogonal to (perpendicular to) the projection plane (that is, there is no foreshortening or perspective).
In the construction industry, the term elevation refers to an orthographic projection of the exterior (or sometimes the interior) faces of a building, that is a two-dimensional drawing of the buildings faades. As buildings are rarely simple rectangular shapes in plan, an elevation drawing is a first angle projection that shows all parts of the building as seen from a particular direction with the perspective flattened. Generally, elevations are produced for four directional views, for example, north, south, east, west.
Simple elevation drawings might show: -
The outline of a building. - Openings such as doors and windows.
Openings such as doors and windows. - Roofing.
Roofing. - Projections such as eves and pipes.
Projections such as eves and pipes. - Level datums such as finished ground level and floor positions.
Level datums such as finished ground level and floor positions.
Key dimensions such as wall lengths and heights.
Exterior features such as decks, porches and steps.
Any portion of the foundation that may be visible.
Exterior wall and roof finishes. - However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
However, they can contain a great deal of detail depending on the reason for their preparation. While insufficient information on elevations can mean that they do not properly satisfy the need for which they were prepared, very detailed elevations can be time-consuming and expensive to prepare. It is important therefore that the reason for the drawing is clear and the level of detail required is specified.
Elevations might be prepared for a number of reasons, including:
As part of a survey of existing buildings.
To create a record of a building. - To explore and communicate interior and exterior design options.
To explore and communicate interior and exterior design options.
To communicate construction information. - As part of an application for planning permission.
As part of an application for planning permission.
As part of an application for building regulations approval.
For sales and marketing. - Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
Historically, buildings have been drawn by hand on two dimensional paper, and so orthogonal projection and the drawing of two dimensional plans and elevations have been the standard means of representation. However, increasingly, buildings are being drawn using computer aided design (CAD) or building information modelling (BIM) software that represents them in three dimensions. Two-dimensional elevations can be generated from these 3D models, but they do not need to be drawn individually.
An easement is a right which a person has over land owned by someone else. Easements are normally attached to the land rather than to a person and can be considered to last in perpetuity.
Examples of easements include: -
Rights of way. - Right to light.
Right to light. - The right for underground services to pass beneath the land of a neighbouring property.
The right for underground services to pass beneath the land of a neighbouring property.
Right of support. - The right to draw water.
The right to draw water. - An easement can be created by:
An easement can be created by: -
Express grant, for example, it may be set out in a conveyance deed or a transfer deed.
Necessity, for example, if there is only one means of access between a site and a public highway.
By prescription, i.e. the act is repeated for a period of at least twenty years.
Easements can be extinguished in several ways: -
Agreement between the parties in the form of a deed.
By implied release, for example it has not been used for a long period of time.
Where the character of the dominant land has changed.
By limitation of time, if a limitation was agreed.
By a change in law. - Easements differ from wayleaves, which are temporary agreements typically used by utilities companies to allow them to install and maintain equipment on privately owned land in return for payment to the landowner and occupier.
Easements differ from wayleaves, which are temporary agreements typically used by utilities companies to allow them to install and maintain equipment on privately owned land in return for payment to the landowner and occupier.
A disbursement is a type of payment which is made from a bank account or other funds, or a payment that a third party such as a solicitor makes on behalf of their client for which they are entitled to reimbursement.
Common examples of disbursements include money paid out for the running of a business, cash expenditures, dividend payments, and payments made by an organisations solicitor to third parties for certain fees (e.g. court, medical, courier fees, expert reports, etc.).
During the conveyancing process, a disbursement is a type of payment made when property ownership is transferred from one party to another. Disbursements are not part of a solicitors basic fee, nor are they additional charges for which the solicitor receives a commission; instead they relate to various fees and taxes that must be paid.
The most common disbursements that can apply to property purchases include:
Stamp duty land tax. - Land Registry fees (to register the change of ownership, along with details of any new mortgage on the property).
Land Registry fees (to register the change of ownership, along with details of any new mortgage on the property).
Official copy entries and filed plans. - Landlords registration fee (may be payable to the freeholder for registering details of the ownership change).
Landlords registration fee (may be payable to the freeholder for registering details of the ownership change).
Search fees. For more information on the various different types, see Search fees.
Some disbursements may need to be paid up-front while others will be required when the purchase completion is due. Some of the fees are of fixed amounts and can be given with the original quote, however, others are variable and will be determined by the property purchase price or the particular charging structure of local authorities.
If a disbursement is collected by a solicitor but then payment of it is no longer required, it must be returned to the client. If the amount actually paid is lower than that taken by the solicitor as a disbursement, then the balance should be refunded to the client.
While some clients may wish to handle the conveyancing process themselves, thereby avoiding having to hire a solicitor, in practice it is can be convenient to use a solicitor to make such payments. This can be because some organisations only accept payments through solicitors and do not directly deal with the public, or because the solicitor has an existing account with a particular organisation. Also, a solicitor is responsible for making sure all relevant payments are made sp that the property purchase can go through as easily as possible, and the layperson may not be fully aware of all those payments that are required.
A developer constructs, redevelops or refurbishes buildings in order to make a profit. They are not the same as a property investors, who purchase completed buildings and sell them or rent them for profit, however, there is clearly considerable overlap. Smaller developers will generally sell developments once they are completed (trader developers), whilst larger developers may be able to retain developments, building up large portfolios of property, in effect acting as a property investor (investor developers).
A developer is distinguished from a contractor in that a contractor is appointed by a client (who may be a developer) to carry out construction works. Contractors profit from the process of carrying out the works, not from the property itself. Developers may undertake construction themselves (for example, housebuilders) or may appoint contractors to carry out the works.
Developers may fund development directly themselves, or seek investors. Development finance may be sought to cover the immediate costs of completing a development, whilst funding can be sought to cover the ongoing cost of holding a completed development. Developers may also seek forward funding where a funder agrees to purchase the completed development. Funding is largely provided by financial institutions or by banks.
Developers may specialise in a particular area or a particular type of development, or may spread their risk by operating across a number of different areas and building types. Development may be speculative, or may be undertaken for a specific occupant.
The key phase in property development is deciding the nature of the development to be undertaken and whether or not to proceed with the development. These decisions are based on an evaluation of the market, and financial appraisal of the proposed development, including the likely constraints, risks and profit. The development process can be summarised as:
Initiation and evaluation. - Land and property acquisition.
Land and property acquisition. - Design and permissions.
Design and permissions. - Construction.
Construction. - Management or disposal.
Management or disposal. - Development is a very complex process. Development evaluation requires assessment of a great number of criteria, funding can be difficult to secure, purchases and sales can take considerable time, and developments can require a great deal of management. As a result, developers require a great deal of expert knowledge in subjects such as:
Development is a very complex process. Development evaluation requires assessment of a great number of criteria, funding can be difficult to secure, purchases and sales can take considerable time, and developments can require a great deal of management. As a result, developers require a great deal of expert knowledge in subjects such as:
Property and land valuation. - Building pathology.
Building pathology. - Investment appraisal.
Investment appraisal. - Funding mechanisms.
Funding mechanisms. - Property law and planning.
Property law and planning. - Design and construction.
Design and construction. - Project management
Project management - Estate management.
Estate management. - Accounting.
Accounting. - The decision to invest in property is taken within the wider context of the global investment market, and an investor may include property as a part of a wider investment portfolio. However, unlike many other investments, property involves long-term commitment to unique, large, high-value assets, that can be created from scratch or can be improved to increase their value, and that require ongoing investment for management and maintenance.
The decision to invest in property is taken within the wider context of the global investment market, and an investor may include property as a part of a wider investment portfolio. However, unlike many other investments, property involves long-term commitment to unique, large, high-value assets, that can be created from scratch or can be improved to increase their value, and that require ongoing investment for management and maintenance.
Depending on the condition of the global investment market, property can be seen either as a safe haven, or can seem too expensive for the risk profile; illiquid, inflexible and too long term compared to higher-returning assets.
NB: Private Finance Initiatives (PFI) are one of the three procurement routes preferred by the government (the other two being prime contracting (or prime-type contracting) and design and build). On PFI projects, a single integrated supply team is appointed with design, construction and facilities management expertise to design and build a development and then to operate it for a period of time.
A special purpose vehicle (SPV), of which the integrated supply team is a part, finances the project and leases it to the government for an agreed period (perhaps 30 years) after which the development reverts to government ownership.
In very broad terms,contractorsare theorganisationsappointedbyclientsto carry outconstruction works.
Abuildingmay need to be altered at somepointafter it has beenconstructedduring its in-use period. This will necessitatealteration work.
The term alliance refers to a: Combination of the industryIntegrated Project Team(IPT) andclientsteam workingtogether for thedurationof the project/programme.
When a firm such as acontractoror othersupplierin theconstruction industrywants to secureworkfor itsbusiness, it will usually submit aproposal(a tender, 'quote' or bid) to a prospectiveclientand in so doing becomes a bidder.
Abill of quantities(sometimes referred to as a 'BoQ' or 'BQ') is adocument, typically prepared by acost consultant(often aquantity surveyor) that providesmeasured quantitiesof the items ofworkidentified by thedrawingsandspecificationsin thetender documentationfor aproject.
Bondsare a means of protection against thenon-performanceof thecontractor.
Many BREEAM-related actions are tied todevelopmentstages as set out in theRIBA Plan of Work.
The aim of thiscreditis to recognise and encourage the use of recycled and secondaryaggregates, thereby reducing the demand for virginmaterialand optimisingmaterialefficiencyinconstruction.
Whether appointing asole trader, or a bigbuildingfirm to take on a largerproject, knowing the background of thebuilderis important. In particular it is crucial to ensure they have the right type ofinsurancefor theworkto be carried out.
Acall-off contract, also known as ablanket order, is apurchase orderwhich enables bulkordersover a period of time.
Capital expenditure (sometimes abbreviated asCapex,CAPEXorCapEx) is one-off expenditure that results in theacquisition,constructionorenhancementof significantfixed assetsincludingland,buildingsandequipmentthat will be of use or benefit for more than onefinancial year.
A 'cooling off period' is a length of time during which thepurchaserofgoodsorserviceshas the right to cancel the purchase and obtain a refund.
BS EN 9145, 2018, defines thedemand rateas the: Quantityofproductsrequired to be produced by theproductionorganization over aspecifiedperiod of time to fulfil thedeliveryschedule.
Clusteringis a method ofpre-qualificationfor theprocurementofconstruction projects. -
In theconstruction industrythe term cost generally refers to the amount that has to (or will have to) be paid to receivegoodsorservices.
Thedelivery model assessment(DMA) is an analytical, evidence-based approach to reach a recommendation on how acontracting authorityshouldstructurethedeliveryof aprojectorprogramme.
Thedemand chainis concerned with all theactivitiesa firm undertakes to generate the demand for itsgoods and services, so it includesmarketing, sales andservice.
Kanbanis aproject managementtechnique that usestoolssuch as billboards orsignstodocumentand streamline the variousstepsin processes.
Landacquisitionis the process of buying a piece of land.
Operation andMaintenanceManuals (O&M Manuals)formpart of the usualhandoverdocumentation and usually include operation andmaintenanceinstructionsalong withManufacturersliterature,As Built Drawingsand Signed Test andCommissioningsheets.
Propertycan be defined as something that a person orbusinesshas legaltitleover. Having legaltitleoverpropertyprovides theownerwith certain enforceable rights.
Bid evaluationis the process that takesplaceafter thetender submissiondeadline. It involves the opening and examining of thebidsto identify the preferred supplier(s) for theproject.
In theconstruction industrythis generally refers to thecontractorbeginning theconstruction works, ie thepointat whichsite clearance,demolition,excavationorconstructionbegins.
ACondition Report(orHome Condition Report HCR) is atype of buildingsurvey.Building surveysare a means of providing anevaluationof apropertyscondition.
Contractregisters provideschedulesofcontractsthat have been let. They might be prepared for a specificprojector by a largecontractingorganisationsuch as alocal authoritywho may have a large number of livecontractsat any time.
This would be the primaryplanforsetting outhowproject informationis to be prepared, who does so, and what protocols and procedures to use.
Early appointmenttypically refers to the involvement at the earliest possible stage in thedesign processof certainstakeholdersto aconstruction project, with the aim of fosteringpartneringand improvedteam working.
In theconstruction industry, the term user or users typically refers to any persons, groups ororganisationswho usepropertyorlandas anoccupier,owner,tenant,visitoror otherstakeholder.
Buildingfacades will generally require regular care. Afacade maintenanceprogrammeis a strategic approach that allowsbuilding managerstodocumentthe specifics of the facadesystembased onmaterialsused,conditionassessment,repairrequirements, budgetary expectations and so on.
"In theconstruction industry, the term 'handover' typically refers to: Handover of the site to the contractor at commencement of the works.
The handover of the completed works to the client. This is sometimes referred to ashandover and close out."
The formal issue ofinformationforreviewand sign-off by theclientat key stages of theproject.
the initial success criteria are thefactorsthat theclientwould initially consider as indications of the success for theirproject.
Aninternal contractis one that exists between a principal and anagent, i.e. theagentis legallyappointedtoacton its behalf.
Land valueis the amount of money that a piece ofland, along with thepropertycontained on it, ispricedat
Aletter of award, also known as an award letter, is sent by a client/employeras written confirmation that atendererhas been successful and will be awarded acontract.
Somebuildingsoractivitiesby their nature require speciallicensesto be permitted tooperate, for example to ensure thathealth and safetystandardsare adhered to.
Thestrategyfor themaintenanceandoperationof abuilding, includingdetailsof any specificplantrequired to replacecomponents.
Amanagement structuresets out the way theclientintends to organise itself for the proposedproject.
The Mean Lean Green philosophy aims to producedevelopmentsthat lower the demand forresources, provide efficientstructuresand deployinnovativetechnology.
Neighbourhood planningwas created to offer... ' a new way forcommunitiesto decide the future of theplaceswhere they live andwork'
Inconstruction, the term 'penalty' typically refers to a financialpaymentimposed in theeventof abreach of contract.
It describes who does what and how, defining thepolicies, procedures and priorities that will beadopted.
Apunch list(also known as asnagging list) is adocumentthat is prepared close to the end of aconstruction projectand issued by the appropriatecertifyingauthority (typically, thearchitect,contract administratororemployers agent). It lists any faults that are identified orworksthat do not conform to thespecifications, which should be rectified prior to acertificate of practical completionbeing issued.
ARAG report(RAG rating, RAG status orDeliveryConfidenceAssessment) presents a statusassessmentusing thetrafficlightcolourdesignations; Red, Amber orGreen.
Order of cost estimatingandcost planningforbuilding maintenanceworks, defines a repair as: workthat is performed to returnequipmenttoserviceafter afailure, or to make itsoperationmore efficient.
ARequest for Information(RFI) (occasionally referred to as aTechnical Query) is a formal question asked by one party to acontracton aconstruction projectto the other party.
Safety auditsare carried out to assesshealth and safetyprocesses onconstruction sites, considering; legislative requirements, industrybest practice, and thecontractorsownhealth and safetymanagementsystems.
In its broadest sense, the term schedule simply refers to a list. That can be a list of items,activities,events,informationand so on.Sometimes schedules will also include dates, such as the dates on which activities listed in the schedule will be carried out (in the construction industry this is more commonly referred to as a programme).
Aschedule of accommodationis an itemised list ofaccommodationfacilitiesand provisions required by theend userof abuilding project.
Questions directed to thedesign teamby thecontractor(sometimes more formally called arequest for information) to clarifyinformationin theBuildingContract documentationor requestinginformationthat was notcompletewhen theBuilding Contractwas agreed.
Very earlyappraisalsof potentialsitesfor adevelopmentmay be carried out by asurveyor, before theappointmentof theconsultant team, during thebusiness justificationstage.
The term cost in theconstruction industrygenerally refers to the amount that has to (or will have to) be paid to receivegoodsorservices. Thetotal costsassociated with adevelopmentmay consist of a number ofcomponents.
The term 'soft landings' refers to astrategyadoptedto ensure the transition fromconstructiontooccupationis 'bump-free' and thatoperationalperformanceis optimised.
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a building's fabric are as insulators. That is, how effective they are at preventing heat from transmitting between the inside and the outside of a building.
In theconstruction industry, the term user or users typically refers to any persons, groups ororganisationswho usepropertyorlandas anoccupier,owner,tenant,visitoror otherstakeholder.
Vested outsourcingis aformofbusiness process outsourcing (BPO)in which theclientand theservice providerappointedto deliver non-primarybusinessactivitiesdevelop sharedbusiness modelsand goals.
TheParty Wall etc. Act 1996is an enablingAct, insofar as it grants theownerof apropertythe legal right to undertake certainworksthat might otherwise constitutetrespassornuisance.
Also referred to as aram attack,ram raidingis a fast and destructiveformof burglary that is planned in advance.
Retentionis a percentage (often 5%) of the amountcertifiedas due to thecontractoron aninterim certificatethat is retained by theclient.
TheSpatial Requirementsfor thebuildingas a whole are set at Stage 0 (strategic definition). By the end of Stage 1 (preparation and briefing), theSpatial Requirementswill have been developed indetailand incorporated into theProject Brief.
Success criteriaare thefactorsthat theclientwould consider as indicators of success for theirproject. These typically are set by theclientat the start of theprojectasinitial success criteriaand develop throughout thebriefingstage to become theproject success criteria.
The term common area refers toareasandamenitieswhich are provided for thecommonuse of more than one person.
Afinancial year sometimes called thetax period,accounting period,fiscal yearorbudget year is the period of time, usually 12 months, that is used foraccountingpurposes and for the submission of taxes to the Inland Revenue.
The Green Book: Appraisal and Evaluation in Central Government' is produced by HM Treasury. It provides astructurefor theappraisalof proposedcentral governmentprojects,policiesandprogrammes, and for theevaluationof existingprojects,policiesandprogrammes.
The term off-plan property refers topropertywhich is available for purchase before it has beenconstructed.
The term public body refers to a formally-establishedorganisationthat is typically created by statute and publicly funded for the purposes of delivering a public orgovernmentservice.
Rateable value(RV) is avaluethat is given to all non-domesticandcommercial properties. It is used to assess the amount ofbusiness ratestheproperty ownerorleaseholdermust pay. It is re-evaluated periodically.
Town planningis the process of managinglandresources. It involves the control of existing and newdevelopments, as well asstrategypreparation to ensure manage future requirements.
Failureoccurs when the desiredoutcomesare not achieved. It is the opposite of success.
In very general terms,detailsconveyaccurateinformationof a very specific nature.Detailscan be superfluous if a general overview is required, but are essential to gain a fuller, morepreciseunderstanding
In very general terms, the word community refers to a group of people who live in samelocation, often sharinghousing,amenities,services,infrastructure, and so on.
Deflection inengineeringterms is the degree to which anelement of structurechanges shape when aloadis applied.
The term 'groundwater' refers to allwaterwhich is below the surface of thegroundand within the permanentlysaturatedzone.
Knowledge management(KM) is the process of making the best use ofknowledgeandinformationwithin anorganisationto achieve objectives. It allows people toaccessand apply the most appropriateknowledgewhen it is needed and supportslearning.
Material(s) banksare repositories or stockpiles of valuablematerialsthat might be recovered.
Material loopsare flows whereinmaterialsor larger parts are recovered frombuildingsand reclaimed, recycled or biodegraded through natural or technological processes
Resource productivityin theconstruction sectorshould be interpreted as themeasureof the annualquantityof extracted virginmaterials, in relation to the (economic)valuecreated from thisquantity.
Very broadly,sheltersprovide physical protection from something that is potentially harmful.
Anabutmentisstructuralcomponenttypically found at both ends of abridge,dam,archorvaultto resist and support the lateral and vertical loading of thosestructuresand to transfer thoseloadsto thefoundations.
Abricklayeris a craftsperson who laybricks, generally withmortar, to create finishedconstruction works, such aswalls,chimneys,parapets,spandrel panelsand so on. In theUKand Australia,bricklayersare colloquially referred to as brickies.
Inconstructionthe term cart away refers to the removal ofmaterialssuch assoilthat need to be taken away fromsite.
Construction sidings aresiteswithconnectionsto the National Rail network to allow excavatedmaterialsto either join the rail network from the Proposed Scheme constructionareas, or to leave the rail network to enter the constructionareas.
ConTechis a phrase that has been coined to identifyadvanced construction technology. It broadly describes the intersection ofconstructionandtechnology.
Acaissonis a box-likestructurecommonly used incivil engineeringprojectswhereworkis being carried out inareassubmerged inwater.
Alayerof unboundaggregateof lowerqualitythansub-base, that is used to improve theperformanceof thefoundationsoilsbefore laying thesub-base, and to protect thesubgradefromdamagebyconstructiontraffic.
Geospatial data(also referred to asgeomatics) isdatacollected aboutelementsof natural,built, social and economicenvironmentsin association with a geographiclocation.
Ground anchors, otherwise known as anearth, percussion driven ormechanical anchors, are versatile devices used to hold, restrain and supportbuilding,civil engineeringand otherstructures, either permanently or temporarily.
A thorough investigation andassessmentofground conditionsand stability is an essential stage of anyprojectinorderto determine issues
Infill panel wallsare aformofcladdingbuiltbetween thestructuralmembersof abuilding. -
In general,installationis theactof installing something in a fixed, semi-fixed or temporarylocation. It can also refer to acompleteunitwhich has beeninstalled.
In apipe,sewer, channel ortunnel, theinvertis the lowestpointupon whichwatercan flow on the inside.
As anelementofroadsandhighways,kerbs(kerbstone,crib-stane(Scots) or sometimescurbs(US)) serve a number of purposes
In theconstruction industry,labouris the term usually given to unskilled, manualworkerson asite, i.e what is normally termed manuallabour or sitelabour.
Lifts(orelevators) inbuildingsare normally totally enclosed by a shaft (typically square or rectangular) that will rise vertically through thebuildingand often terminate aboverooflevel.Lift shaftswill also extend belowgroundif they must serve one or morebasementlevels, or tohouseoperatingequipment.
Alight well(orlightwell) is anarchitecturalfeature that can be used to takenatural lightinto theinteriorspacesof abuilding.
Alightningstrike can exceed 100 millionVoltAmps. Any grounded object that provides apathtoearthwill emit upwards positive streamers or fingers ofelectricalcharge. T
Aliving facadeis a vertical surface incorporating vegetation into itsstructureor face to facilitate variousaesthetic,environmental, social or economicfunctionsand benefits.
Mainconstructioncompounds are strategicconstructionhubs forcoreproject management(engineering,planningandconstructiondelivery), commercial and administrative staff associated with theconstructionof aproject.
Quoinsare large rectangularblocksofmasonryorbrickthat arebuiltinto the corners of awall.
The phrase 'off-site construction' refers to thecompletionofelementsorcomponentsof aconstruction projectat a differentlocationto where they will be permanentlyinstalled.
Overbuild is a relatively recent term that has come to mean achieving betterland usebybuildingover existingpublicassetsto create newresidentialaccommodationwithout the need to findgreenfield sites.
"The term 'excavation' refers to the process of removing earth to form a cavity in the ground, typically to allow a below-ground structure to be constructed.
The term over excavation refers to an excavation that goes beyond the depth required for the formation of a below-ground structure."
in theconstruction industry, the term 'programme' typically refers to the sequence in which a series of tasks must be carried out so that aproject(or part of aproject) can becompleted.
Aproject directoryprovidesdetailsof theorganisationsinvolved in adesignandconstruction project. This may include their role,organisationname, address, phone numbers, email addresses and names of key contacts
anaccess auditofpremisesto identifybarriersto the participation ofdisabled peopleinlifein thearea, deciding on what adjustments are needed, involvingdisabled peoplewhen proposing solutions and identifying priorities, implementing improvements to an agreed timescale,monitoringand reviewing improvements.
astructurehaving a surface in the open air suitable for ingress and egress of persons to abuilding
Active usesare uses that generate many visits, in particularpedestrianvisits, over an extended period of the day.
Activity centreswithincitiesandtownsare a focus forenterprises,services, shopping, employment and social interaction.
The ability to cope with a range ofconditionsor requirements.
Anaditis a nearly-horizontal passage ortunnelthat providesaccessto and fromundergroundworkings in atunnel.
Circular Building Assessmentis anassessmentapproach and method that aims to provide a holisticevaluationand interpretation of multiplesustainabilityaspects ofbuildingsand their parts.
Acircular business modeldescribes howcompaniescan generate revenue or makeprofit, including the way itoperatesandfinancesitsactivities, within acircular economy.
. Given the phenomenal rise ofcircular economythinking in recent years, thewaste hierarchyas it stands may no longer be a valid startingpointforbusiness.
Thecircular value networkof abuildingis the set of interrelatedactivitiesperformed bycompaniesof a specific industry to maintain or increase the social, financial orenvironmental valueof thatbuildingand its parts.
Deconstructionhas been defined as constructionin reverse. Asconstructioninvolves assembling and erectingbuildings, sodeconstructionis thecompleteopposite: it involves takingbuildingsapart piece by piece, avoidingdamageby extracting carefully what is required.
It includes provisions for the re-use ofbuilding componentsat the end of astructure'slife.Design for deconstructionworksalongside otherconsiderationssuch assustainable designandrecycling.
Thewaste hierarchysets out a set of priorities that are based onsustainabilitywith anorderof preference for actions to reduce and managewaste. The overall aim of the hierarchy is to generate the minimumwastepossible by using everymaterialin every way possible.
Ablock planusually shows the siting ofbuildingsasblockslaid out onmapsof the surroundingarea.
Thebuilding regulations, set out legal requirements for specific aspects ofbuilding designandconstruction. A series ofapproved documentsprovide general guidance about how different aspects ofbuilding designandconstructioncan comply with thebuilding regulations.
The term thermal mass describes the ability of amaterialtoabsorb,storeand releaseheat energy.
In terms ofarchitecture,antiquitiescan be said to be thestylesofclassical architecturethat stemmed from those ancient civilisations and those dating later that were influenced by them.
the aspects of abuildingorplacewithin thedevelopmentwhich determines the visual impression thebuildingorplacemakes, including the externalbuilt formof thedevelopment, itsarchitecture,materials,decoration,lighting,colourand texture
Archigramwas a UK-basedartandarchitecturecollective that came to prominence in the 1960s. As part of the burgeoning avant garde of the time, it aimed to explore extreme alternatives tourban designas a response to what it perceived to be the dullness and intellectual conservatism ofmodern architecture.
Design methodologyrefers to thedevelopmentof systematic processes or methods applied in thedesignactivitiesof a particular field of study orpracticelikearchitecture,urban designorindustrialdesign.
The term architectural reprography refers to the reproduction of graphics through various technical processes, for use byarchitects,engineers,designers,surveyors, and so on.
Back-to-back housingis aformofterraced housingin which twohousesshare a rearwall.
Abasementis part of abuildingthat is either partially or completely belowground level.Depending on the size of the property, the amount of excavation and building work required and its complexity, the work for constructing a basement to a house will last typically for 12-20 weeks.
The term 'bearing capacity' refers to thecapacityofsoilto supportapplied loadsthat are acting on it. In theconstruction industry, this typically relates to thecapacityofsoilto supportbuilding foundations, in which case, thebearing capacitycan be calculated from the maximum average contactpressurebetween thefoundationand thesoilthat would not produceshearfailure.
BIM objectsaredigitaldescriptions ofproductsormaterialsthat, when combined with otherBIM objects, create aBIM model.
Blobitecture', also known as 'blobism', is a term given to a post-modernarchitectural stylecharacterised by curved and roundedbuildingshapes, or 'blob architecture'.
The term 'building fabric' refers tostructuralmaterials,cladding,insulation,finishes, etc., that enclose theinteriorof abuilding, separating the internal from the external.
The increasing technical complexity ofmodern buildingshas served to broaden thescopeofbuilding engineering services.
Changes to aprojectmay haveimpactson time,costorquality. Broadly, the later in thedevelopmentof theprojectthat changes occur, the greater thoseimpactsare likely to be.
In thebuilt environment, this generally relates to the movement of people, typically within abuilding.
Commercial lightingislightingused for commercialspacessuch asoffices,stores,institutions,hospitalsandgovernmentbuildings, essentially thosespacesthat are notresidential,industrialor formanufacturing.
TheCommercial style(1890 - 1920) reflects advances inconstruction technologythat permitted the creation of verytall buildings, the firstskyscrapersin theurbanlandscape.
TheCommon Arrangement of Work Sections(CAWS), provides a consistent arrangement forspecificationsandbills of quantities.
Thecommon data environment(CDE), first authored and explained in BS1192-2007 byMervyn RichardsOBE and the BSI publication BIP2207, is thesingle sourceofinformationused to collect, manage and disseminate documentation, the graphicalmodeland non-graphicaldatafor the wholeproject team(i.e. allproject informationwhether created in aBIMenvironmentor in a conventionaldataformat).
Building log booksare required for newbuildingsand for existingbuildingswhere theserviceshave changed.
"Inbuildings,spacesare provided for variousactivitiesto takeplace. In some cases aspaceis only suitable for oneactivity,
Everything that an individual perceives visually that is not to do with their perception of shape, size, surface texture, tone and motion of objects can be termed colour
Within abuilding, acompartment wallis any fire-resistingconstruction(loadbearing or non-load bearing) thatformspart of one or more compartments designed to help contain thespreadoffirefor a designated period of time.
In very general terms,detailsconveyaccurateinformationof a very specific nature.Detailscan be superfluous if a general overview is required, but are essential to gain a fuller, morepreciseunderstanding.
Contingencyplansareplansthan could be enacted tomitigateproject risksidentified duringrisk assessment, if thoserisksincrease or materialise.
Cooling towersrejectheatthrough theevaporationofwaterin a moving air stream within thecooling tower. Thetemperatureandhumidityof the air stream increases through contact with the warmwater, and this air is then discharged. The cooledwateris collected at the bottom of thetower.
Asmaterialstechnologyhas advanced, andsteelandconcretehave been able to achieve higher and highercompressive strengths, so theheightofskyscrapershas increased toheightsthat were previously deemed unrealistic.
Acorridoris aformof hallway orgallerywhich is typically narrow in comparison to its lenght andactsas a passage connecting different parts of abuilding.
Ventilationis necessary inbuildingsto remove stale air and replace it with fresh air:
Acrocketis anarchitecturalelementcommonly used for ornamental purposes to decoratecolumn capitalsandcornices, as well as the inclined edges of spires,finials,pinnacles, andgables.
Crazy pavingis a method ofhard landscapingthat is usually applied topathways,patios,gardensand driveways and is believed to have originated in ancient Rome.
Towercranesare usuallysuppliedon a hire basis, with theclientbeing responsible for thedesignandconstructionof the base upon which thecranewill be erected
Acycle path(orcycling lane) is asectionof roadway reserved for cyclists
Datacomprises facts about things, people,events, states of affairs and other subjects.
In itstraditionalusage in shipping the termdeckrefers to the uppermost, horizontal, workinglevelof a ship. Similarly inconstructionthe term deck refers to a horizontalplatformbut may relate to a range of different applications.
esign and check certificatesaredocumentssubmitted bydevelopersanddesignersofhighwaystructuresinEngland,WalesandNorthern Ireland -
"The CIOB Code of practice for project management 4th edition suggests that design audits are:
Carried out by members of an independent design team providing confirmation or otherwise that the project design meets, in the best possible way, the client's brief and objectives."
Design for deconstruction(ordesign for disassembly) is an important part ofgreen designand aconsiderationof thecompletelife-cycle of astructure.
Design drawingsare used to develop and communicate ideas about a developing design:
Adesign management plancan be used to co-ordinatedesignactivities. -
Ancient woodlandsareareasthat have been continuously wooded since at least 1600 AD (1750 inScotland).
Basementworksare usually large andcomplexundertakings. -
In the United States,building inspectors(also known asconstructioninspectors orbuilding officials) are responsible for ensuring thatconstruction workssatisfy the requirements ofbuilding codes, zoningregulationsand so on
The Secretary of State forCommunitiesandLocal Governmentcan call inplanning applicationsfor his / her ownconsideration, taking over the process of determining the application from thelocal planning authority.
In the United States, acertificate of occupancy(also known as a use-and-occupancycertificate) is adocumentissued by alocal governmentagencyorbuildingdepartment to confirm that abuildingis fit for humanoccupation.
Aplanatlocal authoritylevelshowing the localareasto which a code will apply.
Planning permissionis the legal process of determining whether proposeddevelopmentsshould be permitted.
Planningperformanceagreementsare voluntaryundertakingsthat enablelocal planning authoritiesand applicants forplanning permissionto agree the timescales, actions andresourcesnecessary to process aplanning application.
Planning officers arepublic sectorplanning practitioners. -
Planning legislationsupportsUKplanning policyand takes theformofActsofParliamentandStatutory Instruments(SIs).
The term planning guarantee refers to theGovernment policythat noplanning applicationshould spend more than a year with decision-makers, including any appeal
Planning applicationsare subject tofeeswhich are usually payable to thelocal planning authority. Applicationfeescan change from year to year, so it is important that the applicant orlead designerchecks what thefeewill be with thelocal planning authority.
Planning legislation,policyand procedure is an ever increasinglycomplexpart of thedevelopment process.
anything that affects thequalityofland, air,waterorsoils, which mightleadto an adverseimpacton humanhealth, thenatural environmentor generalamenity.
'Definedareawhereretaildevelopmentis concentrated (generally comprising the primary and thosesecondary frontageswhich are adjoining and closely related to the primary shoppingfrontage).'
In certain cases, even though adevelopmentis permitted,prior approvalof some issues is required from thelocal authority.
In economics,property rightsare theoretical and legalconstructsfor determining control over, and use of, aresourceorgood. The basis for allformsof market exchange is derived fromproperty rights.
Protected areasareplaceswhich, as a result of their particularenvironmentaland/or cultural characteristics, would justify more stringentdevelopment controlsto ensuresustainability
In economics,property rightsare theoretical and legalconstructsfor determining control over, and use of, aresourceorgood.
propertyblight(sometimes referred to as 'planning blight' or 'blighted land') is the reduction in marketability andvalueoflandas a result of apublic sectordecision.
Landis defined by theLawofPropertyAct1925 as including '...landof anytenure, andminesandminerals...buildingsor parts ofbuildings...and other corporeal hereditaments; also...arent, and other incorporeal hereditaments, and aneasementright, privilege, or benefit in, over, or derived fromland.'
Land useis the exploitation oflandand itsresources, that is, the managing and modifying of natural orurban environmentsfor the benefit of humans.
Local Development Orders(LDOs) are intended to enable localplanningto be simplified under certain circumstances.
'Theplanfor the futuredevelopmentof the localarea,drawnup by thelocal planning authorityinconsultationwith thecommunity.
In relation toplanning permission,delegated powersare used byLocal Planning Authorities(LPA) to deal withplanning applications.Delegated powersenableplanning officersto determine applications themselves without needing a decision from theplanning committee.
From 25 June 2013,design and access statementsare only required forbuildingsof more than 1,000 sq. m,housing developmentsof 10dwellingsor more anddevelopmentsrequiringlisted building consent.
A clear articulation of what anareashould be like in the future, developed with thelocal community.
Designationcan be used to protectareasofvalueand scientific interest and to ensure that suchareasare properly managed.
Developer contributionsmay be required as part of the process of grantingplanning permission, either where additionalinfrastructureis required, or tomitigatenegativeimpacts.
Parts of the localareawhere radical, rather than incremental change is planned.
Heat pumps transfer heat from a lowertemperaturesource to one of a highertemperature. This is the opposite of the natural flow of heat and is the same process that is used to extract heat from a fridge.
Access controlis the selective restriction ofaccessto a particularplace,building,room,resourceorinstallation.
Anactuatoris acomponentof a machine that is responsible for moving or controlling a mechanism orsystem, by convertingenergyinto motion.
Anaditis a nearly-horizontal passage ortunnelthat providesaccessto and fromundergroundworkings in atunnel.
Aboileris a piece of technical apparatus in whichfuelsare oxidised to generate thermalenergy, which is transferred towateror steam.
Ablue roofis aroofdesigned for theretentionofrainwaterabove thewaterproofingelementof theroof. -
Blocksareconstructedusingconcreteorcement -
Coal: Includes both primary coal (including lignite, coking andsteam coal) and derivedfuels(includingpatentfuel, brown-coalbriquettes, coke-oven coke,gascoke,gas-worksgas, cokeovengas, blastfurnacegasand oxygensteelfurnacegas).Peatis also included.
Acold roofisroofin which thethermal insulationlayeris located immediately above or between theceilingjoistsmeaning that everything above theinsulation, such as therafters, and anyroof space, will be colder than the livingspacebelow it.
Cob, also known as cobb, is abuilding materialthat comprisessubsoil, straw (or another fibrous organicmaterial),water, and occasionally lime.
Springsare used in a variety of ways in many industries around the world. Thecompression springwas one of the firstspringsto be invented and it has become, by far, one of the most studied type.
3D printing is a manufacturing process that creates physical objects based on digital designs. This is achieved with the help of an additive process, where an object is created by a machine that prints various layers of material until the object is completed.
3D printing in the construction industry may help tackle the housing crisis as it can allow 3D printing offers lower labour costs and construction can be completed more quickly. In addition, 3D printing produces little waste and the various wasted raw materials from printing that include failed prints and concrete waste can be recycled. It also helps simplify construction models and plans - the reason being the shapes and structures desired by designers can be printed with high precision.new structures to be created quickly.
Key players operating in the global 3D printing in construction market includes Zhuoda Group, WASP, Urban3D Company, Cazza Construction Company, Apis Cor, WinSun, Belatchew Arkitekter, DUS Architects, Skanska, Fosters+Partners, Lafarge, Carilliom Plc., Balfour Beatty and Sika, among others.
In September 2018, Italy-based WASP unveiled the infinity 3D printer, a construction system that is mainly used to print sustainable houses. It is designed to fast-track the development of the technological village of Shamballa. This is basically a WASP project that aims to develop various 3D-printed, environment-friendly houses. WASP also developed the worlds largest 3D printers that can build homes from locally-sourced materials by using wind, solar or hydro power. This in turn enables regions that do not have access to electricity to 3D print eco-friendly structures sourced through local resources.
Urban3D Company was founded to respond to the housing crisis in Brazil. The company is currently (2019) testing various prototypes and aims to provide various solutions to the development of Brazilian shantytowns.
Apis Cor, based in Russia, is also adopting 3D-printing technology and is the first company to develop specialised equipment for 3D printing in construction .This equipment aims to print whole buildings on site.
Companies are also focusing on special robots that are used for 3D printing. For example, Cazza, based in the US, built the Cazza X1, concrete house 3D printer that was mainly designed for disaster prone areas. These structures can withstand severe tornados, earthquakes, and others, so that people in vulnerable areas can be provided with immediate housing facilities.
3D-printed technology is also used to explore space. NASA's 3D-Printed Habitat Challenge aims to examine various technologies to build homes in space, such as on Mars or on the Moon.
3D-printing techniques also find applications in aerospace, defense, automobile, health, and mechanical applications among others, with printing materials specified as required. Advanced materials combined with cutting-edging printing technology and various advanced computer algorithms have made 3D technology very affordable; this in turn is expected to drive the demand for this market.
3D Printing in construction is mainly driven by the need for sustainable, new, smart housing and eco-friendly solutions. The affordability and speed of buildings are other factors driving the Asia-Pacific market. Rising demand for commercial buildings is also expected to drive the market. Asia-Pacific accounts for the largest revenue share in the global market. Growth in the Asia-Pacific region is mainly attributed to the increasing usage of 3D-printing in China. Rapid industrialisation, high population and urbanisation followed by a growth in concern for environmental pollution and human health is expected to boost the market demand for 3D printing in the Asia-Pacific construction sector.
An accident book is used on construction projects to record details of any accidents that occur. This is a requirement of the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR). Companies are legally required to have an accident book on sites that have 10 or more employees.
Details of accidents that must be recorded include:
The date and time on which it occurred.
The person who was injured. - Any witnesses.
Any witnesses. - The type and nature of the injuries sustained.
The type and nature of the injuries sustained.
The cause and full circumstances of the accident.
These details should be entered into the accident book by the injured person or a colleague as soon after the accident as possible. This forms a valuable source of evidence in the event of any legal claims, and can also be valuable for employers helping identify systems or processes that need to be changed to make them safer. For example, if it is clear from examining the accident book that a project has experienced a number of accidents involving the movement of vehicles, then the site management team can take steps to address that particular issue.
The Health and Safety Executive (HSE) recommend that all forms of accidents are recorded in the accident book, as even small incidents can provide an warning of more severe accidents that could happen in the future. However, RIDDOR identifies the more serious types of accidents which must be reported to HSE as well as being recorded in the book. These include:
Any injury that stops an employee doing their normal work for a period of 3 days or more.
Major injuries such as broken arms, ribs, legs, etc.
Fatalities. - Disease.
Disease. - Dangerous instance occurring at work such as machinery breaking, scaffolding collapsing and any other appliances defecting and causing damage.
Dangerous instance occurring at work such as machinery breaking, scaffolding collapsing and any other appliances defecting and causing damage.
The information contained in the accident book should be kept in an accessible location on site, usually with a nominated person responsible for accident reporting. Information contained in the book should be kept confidential, and to assist with this, accident books may have removable pages. It is a legal requirement that the information in the book is stored safely for a period of three years.
In very general terms, an agreement is an understanding and statement of intent between two or more parties, which has often been negotiated and sets out their respective rights and responsibilities.
Whether an agreement is legally enforceable will depend on its type and form. A non-binding agreement, also known as a gentlemans agreement is typically oral (but can be written), or may be part of an unspoken agreement, and relies on an understanding between the parties that they will honour the agreement as opposed to it being enforceable. A binding agreement is also known as a contract and creates rights and obligations between the parties.
There are four essentials in forming a contract:
Two or more parties. - An intention to create legal relations.
An intention to create legal relations. - An agreement.
An agreement. - Consideration. (Save for contracts made under seal, and subject to the Contracts (Rights of Third Parties) Act, the courts will not enforce gratuitous promises. There must be valuable consideration. Valuable consideration is 'something of value in the eye of the law'.
Consideration. (Save for contracts made under seal, and subject to the Contracts (Rights of Third Parties) Act, the courts will not enforce gratuitous promises. There must be valuable consideration. Valuable consideration is 'something of value in the eye of the law'.
For more information see: Essentials of a contract.
Contracts may be executed under seal (signed by the parties, witnessed and most importantly made clear that it is executed as a deed) or under hand (a 'simple contract' that is just signed by the parties). For more information see: Contracts under seal v under hand.
Contract documents for a construction contract will often include articles of agreement. These set out the core obligations of the parties involved. Typically, they consist of four sections:
Recitals. - Articles.
Articles. - Contract Particulars.
Contract Particulars. - Attestation.
Attestation. - For more information, see Articles of agreement.
For more information, see Articles of agreement.
When an agreement is made to appoint consultants, this generally referred to as an appointment rather than a contract. For more information see: Appointing consultants.
Other types of contractual agreement include: -
Framework agreements, often used by clients that are continuously commissioning construction work, to allow them to invite tenders from suppliers of goods and services to be carried out over a period of time on a call-off basis as and when required. For more information, see Framework contract.
Partnering is a broad term used to describe a collaborative management approach that encourages openness and trust between parties to a contract. The parties become dependent on one another for success and this requires a change in culture, attitude and procedures throughout the supply chain. Partnering can be arranged either by use of a traditional contract with a separate partnering agreement, or by use of a contract with an aligned partnering agreement. For more information, see Partnering.
Pre-Construction Services Agreements (PCSAs) enable clients to employ contractors before the main construction contract commences. Typically, they are part of a two-stage tender process, used in the first stage to procure contractor involvement in the design process. For more information, see Pre-construction services agreement.
There are many other types of agreements used in the construction industry, including:
Planning performance agreement. - Service level agreement.
Service level agreement. - Concession agreement.
Concession agreement. - Non-disclosure agreement.
Non-disclosure agreement. - Working rule agreement.
Working rule agreement. - Heritage partnership agreement.
Heritage partnership agreement. - Hold harmless agreement.
Hold harmless agreement. - Listed building heritage partnership agreement.
Listed building heritage partnership agreement. - Project labor agreement (PLA).
Project labor agreement (PLA). - Reservation agreement for property purchase.
Reservation agreement for property purchase. - Section 38 agreement - adoption of highways.
Section 38 agreement - adoption of highways. - Section 184 agreement - vehicle crossings over footways and verges
Section 184 agreement - vehicle crossings over footways and verges
Section 278 agreement - works to existing highways.
Clustering is a method of pre-qualification for the procurement of construction projects. It applies the concepts of cluster analysis (which is a statistical technique used in many fields, including marketing, social science and computer science) as a classification method often used for data mining purposes.
When used in statistics, cluster analysis is used to divide data into groups (clusters) based on similar traits or characteristics. The goal is to identify traits that are meaningful, useful or both.
Cluster analysis refers not to one specific algorithm, but to the general task to be solved. The appropriate clustering algorithm and parameter settings depend on the data being gathered and the intended use of the results. There are roughly 100 different types - but one that is correctly selected can help to resolve an unwieldy or seemingly illogical decision making process.
Consider this example: there are a number of items in a room and each item has a set of characteristics (size, shape or colour). How will the items be grouped? Will it be based on size, shape or colour? This decision may be based on many factors, depending on how many items there are, their properties, priorities and so on.
Construction projects often attract a large number of potential suppliers with numerous characteristics.Under these circumstances, the prequalification process can sometimes require a significant commitment of time and resources.
The cluster analysis technique can be explored to identify common traits. These traits can then be used to group contractors based on their shared characteristics or abilities. Its purpose is to remove subjective rationale behind supplier selection and instead relies more on a pure data-based on evaluation.
Ideally, clustering organises suppliers by assigning values to key selection criteria. The end result is ideally a rational selection process based on evaluating each vendor, assigning a classification making a selection.
The analysis of data may include discerning trends and patterns, their interpretation and communication.
Cloud computing comprises a network of web-based platforms that allow users direct access to the 'cloud' (the internet) for a range of computing services that include storage, databases, networking, servers, software and analytics. In other words, it is about the use of external IT resources for internal purposes and is a relatively new phenomenon in the building industry. These services are typically provided by companies called cloud providers.
Cloud computing can allow building professionals better and faster access to more flexible resources; this has the potential to speed-up the construction process and so bring greater efficiencies.
Before the cloud, information would have been processed and stored locally on the hard drives of individuals or organisations. This meant computer users were limited by the capacity of their hardware, in terms of both storage and processing power. However, with the advent of broadband came the ability to transfer and process data very quickly over the internet which allowed users to store and retrieve information on, and from, other servers in the cloud. What is more, they can do this from anywhere, on any device. The advent of cloud computing has therefore removed the limitations of hardware, improved accessibility and minimised data loss.
Using the cloud, construction professionals are able to access project drawings, models and other information and collaborate in real time without being in each others presence. This allows remote collaboration without the requirement for travel to meetings. The project information is stored in the cloud, accessed when required, changed, saved and sent back to the cloud for storage. Using the cloud can also give access to additional processing capbailities, software, artificial intelligence and a host of other benefits.
On site, tradesmen or professionals can access or contribute to project information without having to wait to get back to the office. Likewise, a BIM model that is stored in the cloud is easily accessed by all the project team. But the cloud may also have limitations: project owners may restrict access to information, depending on the sensitivity of the project, and absolute security must be assured.
Construction may be one of the least digitised industries in the world, but a survey by Sage in 2017 found that 85% of contractors had already implemented or were planning to implement cloud solutions.
Contract management is the process of managing contracts that are made as part of the delivery of a built asset. It involves the creation, analysis and execution of contracts by the parties to those contracts to ensure operational and financial performance is maximised, and risks are minimised.
Contract management can categorised into three phases: -
Pre-contract phase: Tenders documents are prepared, tenders are sought and contract negotiation is undertaken (see contract conditions and contract negotiation for more information).
Contract execution phase: The final contract documents are prepared for execution (see contract engrossment for more information).
Post-award phase: Compliance with conditions of the contract.
A contract manager might be identified to manage one, or several contracts, or to work as part of a team of contract managers. On large, complex projects, involving several contracts (such as a construction management project) a consultant might be appointed to perform the role of contract manager.
This role might include: -
Assessing the needs of the business or project.
Assessing the market. - Risk assessment.
Risk assessment. - Determining procurement methods and tender assessment criteria.
Determining procurement methods and tender assessment criteria. - Preparing a contract management strategy.
Preparing a contract management strategy. - Preparing budgets and cost estimates.
Preparing budgets and cost estimates. - Preparing programmes.
Preparing programmes. - Selecting the form of contract.
Selecting the form of contract. - Preparing tender documents.
Preparing tender documents. - Seeking tenders.
Seeking tenders. - Negotiating contract conditions.
Negotiating contract conditions. - Contract engrossment and execution.
Contract engrossment and execution. - Briefing project teams, contractors and suppliers.
Briefing project teams, contractors and suppliers. - Being the point of contact for the parties to the contract.
Being the point of contact for the parties to the contract.
Relationship management. - Contract administration.
Contract administration. - Managing variations to the works.
Managing variations to the works. - Supplying information to resolve disputes.
Supplying information to resolve disputes. - Preparing information for the completion of contracts.
Preparing information for the completion of contracts. - Contract managers should:
Contract managers should: -
Be able to manage multiple projects. - Have a good knowledge of construction activities and technologies.
Have a good knowledge of construction activities and technologies.
Have a good knowledge of contract law. - Have good maths and IT skills.
Have good maths and IT skills. - Be good at problem-solving.
Be good at problem-solving. - Be good at negotiating.
Be good at negotiating. - Have good communication and presentation skills.
Have good communication and presentation skills. - An effective contract management strategy can bring a number for benefits to this process:
An effective contract management strategy can bring a number for benefits to this process:
Expected business benefits and financial returns are more likely to be realised.
Good working relations can be maintained with contract partners and subcontractors, and so there is a reduced risk of disputes and a higher chance of repeat work.
There are fewer unforeseen events. - Contract partners, subcontractors and suppliers are likely to be more cooperative and responsive.
Contract partners, subcontractors and suppliers are likely to be more cooperative and responsive.
Contract management can be a complex process, which can be simplified with the use of contract management software. This can be particularly helpful for contract management involving multiple contracts and multiple parties, creating integrated systems for; document management, change control, relationship management, accounting, project management, contract administration, resource allocation and so on. Specialist software is available for different types of contract management, such as large contracts, small contracts, multiple contracts, civil engineering and so on.
Contract registers provide schedules of contracts that have been let. They might be prepared for a specific project or by a large contracting organisation such as a local authority who may have a large number of live contracts at any time. Where the situation is very complex, there may be a number of sub-registers, for different projects, departments or locations.
Contract registers provide an invaluable record, helping track contract status and can be used by public organisations to provide transparency.
A main contractor may establish a contract register during the mobilisation stage of a project. This can be provide crucial information, not just for tracking contracts, but if for example the main contractor becomes insolvent.
A contract register might include information such as:
An identification number for the contract. - The purpose of the contract.
The purpose of the contract. - Location of the works.
Location of the works. - Who the contract is with (this is not always as clear as might be hoped see for example Derek Hodd Limited v Climate Change Capital Limited)
Who the contract is with (this is not always as clear as might be hoped see for example Derek Hodd Limited v Climate Change Capital Limited)
Who signed the contract and when. - Where the original executed contract can be found.
Where the original executed contract can be found.
Who is responsible for the contract. - The status of the contract.
The status of the contract. - Payments made.
Payments made. - Retention.
Retention. - The start date.
The start date. - The completion date.
The completion date. - Details of any extensions of time or changes to the contract sum.
Details of any extensions of time or changes to the contract sum.
Contract registers will generally be prepared digitally, and may be configured so that information is imported from or exported to other databases or software or so that reports can be generated automatically. Consideration may need to be given to security issues and confidentiality of information in relation to some contracts.
Contract management software may be used for recording contract details and tracking progress, providing contract managers with up-to-date information and enabling them to make better decisions.
The contract sum is the price agreed with the contractor and entered into the contract. The agreed contract sum should be calculated and checked very carefully as errors are deemed to have been accepted by both parties.
However, the contract sum does not constitute a 'fixed price' even if the contract is described as a fixed price contract, a lump sum contract or a guaranteed maximum price contract. A truly fixed price would actually not be in the interests of the client as it would mean they could not make changes to the works, and would require that the contractor price risks over which they may have no control, and which might not arise.
Cost engineering is the practice of managing the costs involved on a construction project. This includes activities such as cost control, budgeting, forecasting, estimating, investment appraisal and risk analysis.
While cost engineering relates more to engineering projects and processes, it can also be used as a broad term for the responsibilities of different roles, including:
Bid writer. - Commercial manager.
Commercial manager. - Cost consultant.
Cost consultant. - Project manager.
Project manager. - Quantity surveyor.
Quantity surveyor. - Estimator.
Estimator. - The primary aim of cost engineering is to achieve the ideal balance between the price, quality and time obligations of a project.
The primary aim of cost engineering is to achieve the ideal balance between the price, quality and time obligations of a project.
Those responsible for cost engineering are typically concerned with the relationships between the physical and cost components of what is being designed.
A cost engineer is a professional who, as a result of training and experience, is competent in the use and development of the principles of cost engineering.
Cost engineers can be employed as consultants to manage and/or assess the costs of a project or organisation. They may be consulted before a project begins, or before a tender is submitted, so that budgets can be assessed and forecasts made.
The date for completion is the date by which the contractor is expected to complete the works, which may be earlier or later than the contract completion date.
A design build operate (DBO) contract is a project delivery model in which a single contractor is appointed to design and build a project and then to operate it for a period of time.
The common form of such a contract is a public private partnership (PPP), in which a public client (e.g. government or public agency) enters into a contract with a private contractor to design, build and then operate the project, while the client finances the project and retains ownership.
This differs from a design build finance and operate (DBFO) contract in which the contractor also finances the project and leases it to the client for an agreed period (perhaps 30 years) after which the development reverts to the client.
It also differs from the traditional design and build contract in that it includes operation and maintenance of the completed works, which means that the contractors duties and responsibilities to the client do not end at final acceptance but continue through a defined operational term.
In theory, this encourages the contractor to develop a project with its long-term performance in mind from the outset, rather than just considering the efficiency of its construction, as the contractor will be responsible for any high operating, maintenance or repairs bills. However, it ties both the client and the contractor into a very long-term relationship that can be difficult to price. As a result, contractors may price considerable risk into their tenders, and so the client may not always achieve a best value outcome.
NEC4 Design, Build and Operate Contract (DBO) was released in 2017. This is not only intended for the 'traditional' DBO approach, but is also available for situations in which a client wants to have an existing facility or asset operated by the contractor while it is being upgraded or extended.
Design coordination is a broad term describing the integration of designs prepared by different members of the project team to create a single, unified set of information that can be constructed without clashes between components. Effective design coordination can help to reduce costs, delays and disruption that can be caused by problems on site and the need for remedial or abortive works and redesign.
In its broadest sense, design coordination can simply mean ensuring that designers understand what they are responsible for, and in particular who is responsible for the interfaces and junctions between different design packages. In a more specific sense, design coordination can refer to the actual process of ensuring that design solutions can be integrated, in particular, mechanical, electrical and plumbing (MEP) designs, which as they permeate through the entire building are frequently the source of coordination problems. This is particularly true for complex buildings such as hospitals where there may be a great number of building services that need to be installed in relatively confined spaces.
Direct employment (sometimes called direct labour) is a situation in which an organisation employs operatives directly rather than relying on sub-contractors or self-employed operatives. For example, a contractor may employ bricklayers themselves, rather than subcontracting out bricklaying to another organisation. It is quite common for local authorities to have their own direct labour department to undertake building work and to pay their wages.
Civil Engineering Procedure, 7th edition, published by the Institution of Civil Engineers, defines the term direct labour as: A promoters (clients) own employees employed on construction, sometimes under the internal equivalent of a contract, otherwise as a service department.
Britain emerged from the Second World War with a construction industry dominated by very large contractors that had grown from war time work and were rebuilding a country ravaged by the Blitz. Wimpey were the biggest of these contractors, directly employing most of the labour necessary to execute its projects. Taylor Woodrow, even with half the annual turnover of Wimpey, employed 40,000 people.
Today however, as buildings have become more complex, it is less and less likely that any one contractor will have the required skills to carry out all of the works necessary to construct them, and it does not make good commercial sense to take on new employees for one project that would then have to be laid off for the next. Increasingly therefore, contractors use sub-contractors to carry out particular elements of the works.
In very broad terms, 'digital' refers to signals or data that are expressed by the digits 0 and 1.
Digital technology refers to the systems, hardware and processes that use digital data or signals to achieve a particular set of user-defined results. It pervades most walks of modern life and is the basis for telecommunications, computer systems, navigation and photography, but also manufacturing and finance, to name but a few.
In construction, digital technology has caused a cultural shift and comprises the set of tools that use and manipulate digital data to help improve, deliver and operate the built environment. These tools include:
Use of drones to facilitate site surveys - Facilitating remote meetings (eg Skype)
Facilitating remote meetings (eg Skype) - Artificial Intelligence (AI) and machine learning.
Artificial Intelligence (AI) and machine learning.
3D printing - Communications such as email.
Communications such as email. - Software such as computer aided design, computer aided manufacture and building information modelling.
Software such as computer aided design, computer aided manufacture and building information modelling.
Internet of things. - Cloud-based computing
Cloud-based computing - Virtual reality
Virtual reality - Digital technology has brought about improved collaboration within the building team, and between it and other stakeholders. It has also resulted in new materials and processes, greater innovation and buildings that would have been either very difficult or impossible to design and construct before the advent of the digital revolution. Digital technology is not only achieving better results at every level, but is also helping to make construction safer, more collaborative and more efficient.
Digital technology has brought about improved collaboration within the building team, and between it and other stakeholders. It has also resulted in new materials and processes, greater innovation and buildings that would have been either very difficult or impossible to design and construct before the advent of the digital revolution. Digital technology is not only achieving better results at every level, but is also helping to make construction safer, more collaborative and more efficient.
The term environmental impact refers to the possible effects a particular action may have on the natural environment. These effects can be either negative or positive.
According to the UK Green Building Council (UKGBC), the construction sector uses more than 400 million tons of material each year, much of which has a negative environmental impact. In particular, the products that are used during the construction process can be damaging due to intensive extraction of raw materials, transporting to manufacturing plant and site, energy consumption in manufacture and in use, waste generation and so on.
In addition, the Environmental Protection Agency (EPA) has highlighted the significant change in the surface of a land due to construction activity which involves clearing vegetation, excavation, disrupting habitats, changes to drainage patterns and the water table, noise pollution, light pollution, dust, vibration and so on.
The Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 2011 sets out a requirement to carry out an environmental impact assessment (EIA) as part of the planning application process for certain projects (generally large or environmentally complex projects).
The purpose of an EIA is to ensure that the environmental effects of a proposed development are properly considered. An EIA provides the local planning authority with better information about certain types of project enabling them to make a more informed decision about whether permission should be granted and to allow imposition of more appropriate conditions and obligations to mitigate possible negative impacts.
Ecological Impact Assessments are a key part of EIAs. These identify, quantify and evaluate the potential impacts of on ecosystems or their components.
For more information see: Environmental impact assessment.
A construction environmental management plan may be developed, outlining how a construction project will avoid, minimise or mitigate impact on the environment and surrounding area.
Environmental scanning is a process in which an organisation monitors its internal and external environment as a means of formulating or altering a strategic plan. It involves the ongoing tracking of trends, occurrences, patterns and relationships within its different environments and detecting early indications of opportunities or threats to the current and future plans of the organisation.
In a construction context, an organisation may gather information about the external environment; its competitors, pricing, technology, legislation, government policy, consumer behaviour, as well as information about its internal environment; its strengths and weaknesses.
This allows the state of the organisation to be assessed, and compared to the vision for where it plans to be in five or ten years time. This can be used to develop a forward strategy, identifying changes to company policy, objectives, activities and so on that can be made.
One popular method of environmental scanning is SWOT analysis. Each letter stands for one area to review: Strengths, Weaknesses, Opportunities, and Threats. The strengths and opportunities are factors within the company, and the weaknesses and threats come from sources outside the company.
Most scans include a thorough look at competition, economics, technology, legal issues, and social/demographic factors.
The term estimate is a very broad one that refers to any activity that attempts to quantify something. In the construction industry, it is typically used in relation to the approximate costs associated with a construction project, used, for example to assess the viability or affordability of the project or aspects of it.
An estimate is an attempt to predict the likely expenditures associated with a project as accurately as possible. The degree of detail and the accuracy of estimates will typically increase as the project progresses, more decisions have been made, and more information is available, however, their true accuracy only becomes apparent once the project is complete and the actual costs incurred.
At the outset, estimates may be made to help determine whether a project is affordable and to set a budget. They will then be used to test design options to ensure they are in line with the budget.
A pre-tender estimate (PTE) is a final estimate of the likely cost of the works that are described in completed tender documents prepared to seek tenders (offers) from prospective suppliers.
Contractors, subcontractors and suppliers will then prepare definitive cost estimates to submit tenders in the construction bidding process to compete for the award of contracts.
There are a number of methods available for estimating, depending on the stage of the project and the information available:
Benchmarking, which is a process by which other similar projects are used as comparisons.
Breaking down an overall estimated construction cost into percentages for different elements, based on the experience of the cost consultant.
Measuring defined quantities from drawings. - Initial cost estimates might include wider project costs that the client might incur, such as; fees, equipment costs, furniture, the cost of moving staff, contracts outside of the main works, and so on. Later in the project, estimates are likely to focus on the construction cost of the project. It is important to be clear therefore what costs are being included in estimates, and estimates might be accompanied by a schedule of the assumptions that have been made.
Initial cost estimates might include wider project costs that the client might incur, such as; fees, equipment costs, furniture, the cost of moving staff, contracts outside of the main works, and so on. Later in the project, estimates are likely to focus on the construction cost of the project. It is important to be clear therefore what costs are being included in estimates, and estimates might be accompanied by a schedule of the assumptions that have been made.
Estimates will generally include contingencies, which are downside risk estimates that make allowance for unknown risks associated with a project. At the preliminary business plan stage, estimates might include a 15% contingency, but this may then be reduced as the project progresses and risks pass.
A general foreman, sometimes also known as a site supervisor or construction works manager, is responsible for general management, organisational and operational control of a construction site.
The role of general foreman differs from that of a site foreman in that they must have an overall understanding of the different construction disciplines in order to organise all site teams, inspect their work and control the overall job. By contrast, a site foreman generally oversees the work of one or two teams rather than multiple disciplines.
As well as being in overall control of the construction sites operational activities, the general foreman is often responsible for placing material orders, coordinating health and safety inspections, providing safety briefings, and so on.
On some projects, the general foreman may be in sole control of the site, whereas on larger and more complex projects they may work alongside a project manager and/or site manager. In these circumstances, the site manager may take some of the responsibilities for material ordering and health and safety inspections, as there are more working gangs and disciplines on site which require the general foremans operational control.
A general foreman must have several years of site experience, and generally progresses up from being a site foreman working across a number of different disciplines. They should have an excellent knowledge of materials handling and the internal procedures of their organisation.
The term 'Green supply chain management' (GSCM) refers to the concept of integrating sustainable environmental processes into the traditional supply chain. This can include processes such as product design, material sourcing and selection, manufacturing and production, operation and end-of-life management.
Instead of simply attempting to mitigate the environmental impact of the supply chain, GSCM involves driving value creation throughout the supply chain organisations to reduce total environmental impact.
While the specific goal of GSCM is often the reduction of CO2 emissions, other tangible benefits for an organisation include; greater efficiency of assets, less waste production, greater innovation, reduction of production costs, reuse of raw materials, increased profitability, perception of added value to the client base, and so on.
Integral to the success of GSCM is the approach taken by each party to their upstream and downstream partners in the supply chain. A much greater degree of collaboration, transparency and integration of supply chain processes and systems is required for the initiative to be effective.
Ground investigations are a means of determining the condition of the ground, ideally before beginning construction works. They focus specifically on intrusive geotechnical work such as trial pits and boreholes, and so differ from wider site investigations which tend to involve the collation of more general information from the client, from desk studies, walkover surveys, and so on.
Ground investigations help determine: -
Water table level and water flow. - The nature of faults, fissures and voids in the underground.
The nature of faults, fissures and voids in the underground.
Ground layer thicknesses and the mechanical properties of soil.
Detailed information about soil and ground samples. -
There are a number of techniques that can be used for ground investigations, either individually or in combination. When deciding on the nature, scope and level of detail of ground investigations, consideration should be given to the positive influence information can have on reducing project risks, rather than just the costs of the investigations themselves.
Trial pits and trenches - Trial pits and trenches are a means of investigating shallow ground conditions and developing an understanding of the profile of soils within the ground. They can be particularly useful where buried structures or contamination is suspected or needs further investigation.
Trial pits and trenches are a means of investigating shallow ground conditions and developing an understanding of the profile of soils within the ground. They can be particularly useful where buried structures or contamination is suspected or needs further investigation.
They can be excavated by hand or backhoe excavator, generally to a depth of up to 3.5-4.5 m. Trial pits and trenches can be more cost effective than boreholes but they do not allow for the same depth.
Window sampling, windowless sample boreholes and dynamic probing
Window sample and windowless sample boreholes can be a quick and economical method for obtaining soil samples, which are recovered by inserting tubes of varying lengths into the ground. They are generally restricted to shallow depths but are suited to sites with limited access, sloping sites, and where minimal disturbance is required.
This is a particular advantage with window sampling which uses tubes with longitudinal openings cut into them and are inserted using either hand-held pneumatic samplers or tracked percussive samplers.
Dynamic probes use similar plant to provide strength profiles of the ground and enable a range of instrumentation to be installed such as piezometers, gas and groundwater monitoring wells, and so on.
Light cable percussive boreholes - Light cable percussive boreholes can be suitable for sites that have poor access or low headroom. Tripod rigs are used to drill boreholes of up to 450 mm diameter and depths of up to 70 m. This can be a relatively economical technique and is suitable for weaker soils and where high-quality samples are required.
Light cable percussive boreholes can be suitable for sites that have poor access or low headroom. Tripod rigs are used to drill boreholes of up to 450 mm diameter and depths of up to 70 m. This can be a relatively economical technique and is suitable for weaker soils and where high-quality samples are required.
Rotary boreholes - Rotary boreholes are used where drilled exploration through rock and other solid geological formations such as dense gravel is required. Depths of up to 100 m can be achieved. Bedrock samples can then be taken to the laboratory for examination.
Rotary boreholes are used where drilled exploration through rock and other solid geological formations such as dense gravel is required. Depths of up to 100 m can be achieved. Bedrock samples can then be taken to the laboratory for examination.
Rotary open-hole boreholes are drilled where an understanding of the presence of voids is more important than the structural details of the ground, and are typically used in areas where mine workings are likely.
Rotary cored boreholes are drilled when the structural details of the underlying rock are required. A core barrel is lowered into the drilled hole and a flush circulated with air/mist or water.
Sonic drilling - Sonic drilling involves sending high frequency mechanical oscillations down a drill string to the bit. These vibrations fluidize soil particles at the face of the bit which allows for easy penetration through most geological formations where other techniques may be less successful, particularly where the strata is varied. The specific geological conditions will determine the precise frequency to be used.
Sonic drilling involves sending high frequency mechanical oscillations down a drill string to the bit. These vibrations fluidize soil particles at the face of the bit which allows for easy penetration through most geological formations where other techniques may be less successful, particularly where the strata is varied. The specific geological conditions will determine the precise frequency to be used.
Haul roads are temporary roads provided within a contractors site area to allow for the movement of construction materials, construction machinery and/or construction labour around the site.
Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
An activity is an operation or process consuming time and possibly other resources. An individual or work team can manage an activity. It is a measurable element of the total project programme.
A hanging activity is an activity not linked to any preceding or successor activities. It is sometimes referred to as a dangling activity.
Definition - Circular Building Assessment is an assessment approach and method that aims to provide a holistic evaluation and interpretation of multiple sustainability aspects of buildings and their parts.
Circular Building Assessment is an assessment approach and method that aims to provide a holistic evaluation and interpretation of multiple sustainability aspects of buildings and their parts.
Taking a life cycle approach, aspects that are included are the environmental impact, financial costs, health consequences and social value of the object under study. Developed within the BAMB-project, Circular Building Assessment fosters better informed decision-making about circular alternatives compared to linear, business as usual options.
Guidelines - Environmental impacts of construction products and buildings are typically evaluated using life cycle assessments (LCA), and financial impacts by means of life cycle costing (LCC). Conventionally, their implementation is not without flaws. Despite European standards and recommendations, modelling closed material loops is not harmonised across the continent for example.
Environmental impacts of construction products and buildings are typically evaluated using life cycle assessments (LCA), and financial impacts by means of life cycle costing (LCC). Conventionally, their implementation is not without flaws. Despite European standards and recommendations, modelling closed material loops is not harmonised across the continent for example.
Also, social value assessments are many and varied, covering a plethora of aspects of societal costs and benefits. Moreover, most metrics in conventional societal impact or value studies, do not have a relevance when rethinking value networks in construction, and the economy in general. Therefore, a mayor revision of those assessment methods was indispensable.
Circular Building Assessment is facilitated through data extraction from Building Information Modelling (BIM) and Material Passports where available. Consequently, from a certain level of detail, an evaluation of the transformation capacity and reuse potential of the building and its key parts can affect the assessment outcomes for all aspects.
Moreover, the BAMB project aims to compare within the Circular Building Assessment method the overall impact of the replacement of new products with reclaimed ones, of service life extensions resulting from improved transformation capacity, and the future reuse of parts enabled by their increased reuse potential.
In construction, a skip is a container that is used for holding waste and debris produced by works such as building, demolition, landscaping, and so on. When full it is loaded onto the back of a lorry and taken away for the waste to be disposed of. A skip may also be used to deliver materials to site before then being used as waste storage.
Skips typically have two trapezoid sides, the shorter edge at the bottom and the longer edge at the top. This results in sloping faces at both ends, sometimes with hinges allowing them to be opened for manual loading or unloading. Lugs on each of the top corners allow chains to be attached so they can be lifted on and off lorries.
Skips are suitable for the following materials: - General waste.
General waste. - Inert materials such as concrete, aggregates, ceramics, steel and so on.
Inert materials such as concrete, aggregates, ceramics, steel and so on.
Spoil and soil waste. - Recyclable materials.
Recyclable materials. -
Some of the materials and items that are not suitable for skips include:
Asbestos and other hazardous materials. - Batteries, fluorescent tubes, gas canisters, and so on.
Batteries, fluorescent tubes, gas canisters, and so on.
Electrical appliances and equipment. - Cooling equipment and air conditioning units.
Cooling equipment and air conditioning units. - Liquids such as oil, petrol, paint and so on.
Liquids such as oil, petrol, paint and so on.
Hiring a skip is an important part of site waste management and efficient waste disposal. The larger they are, the are cheaper per cubic yard of waste removed, but if the skip is too large for the amount of waste then it will not be fully used.
When deciding on a skip operator, it is worthwhile checking with the Environment Agency that they are correctly licenced to carry waste. This can be done by acquiring their waste carrier licence number and checking its validity. It may also be sensible to acquire a copy of the operators public liability insurance details, in case of accidents or damage to property when delivering or collecting the skip.
If a skip is to be placed on a public highway, a skip hire permit should be applied for and if necessary, a parking suspension put in place. Councils may not permit maxi skips to be placed on a public highway.
Skips will generally have to comply with local authority requirements relating to positioning, signage, lighting and so on.
For more information, see Getting a skip hire permit.
Skips are typically collected within 1 or 2 weeks of them being delivered, but this can generally be adjusted on request. Prices for skip hire will vary depending on locaion, duration, size, the type of material being stored. It is important to ensure that the skip is not overfilled. Instead it should be filled till it is level. If it is overfilled, the operator may charge more to take it away or ask that excess waste is removed.
Accruals are a form of accounting practice that can help to provide an more accurate representation of the economic condition of a project programme or organisation at the end of an accounting period or year.
Accruals are amounts that are unaccounted for, either because they are revenues earned or expenses incurred, that have not yet been recorded in the accounts. Recording, or estimating accruals enables an organisation to keep records of revenue and expenses that have not been received or incurred. This is particularly important in the construction industry where the supply chain is complex and extended, and invoices may not be paid for several weeks, or even months.
This differs from the cash method of accounting which involves the recording of revenue when it is received and the recording of expenses when they are paid. This raises the problem that revenue is not tied to the expenses that contributed to the generating of the revenue, which can make it difficult to identify the profitability of operations.
In the accrual method, income is reported in the year that the expenses that were incurred to generate that income have been paid. Expenses are reported only once goods and services have been delivered or provided.
Agency is a legal term for a fiduciary relationship created between two parties, in which the agent is obligated to perform a service or supply goods for the principal.
When agency is formed, the principal authorises the agent to undertake certain acts for them and on their behalf, and they are bound by the acts of the agent. For example, one type of agency is between an employer (principal) and employee (agent).
Agency is an essential part of commercial and financial transaction as a legal entity such as a business can only function through its agents.
Agency can be created by: -
Express agreement (oral or written). - Implication.
Implication. - The principals conduct.
The principals conduct. - The legal doctrine of estoppel prevents the principal from rejecting or denying the existence of agency where they have previously established it.
The legal doctrine of estoppel prevents the principal from rejecting or denying the existence of agency where they have previously established it.
In the construction industry, the term 'agent' is often used in relation to:
Employer's agent - an agent acting on behalf of a client as the contract administrator for design and build contracts.
Estate agent - acting on behalf of a client for the sale or rental of properties, businesses or land.
Sub-agents - usually appointed on large construction projects to manage a specific part of the works or a specific package of work.
Client's agent of client's representative - responsible for managing a project on behalf of a client.
The term admeasurement is thought to have originated in the ICE Conditions of Contract measurement clauses, where it referred to establishing the difference between the final quantity of work carried out and the quantity originally anticipated.
There is a subtle difference between admeasurement and remeasurement, in that remeasurement refers to the entire process of measuring again the quantities of work undertaken, whereas admeasurement refers only to the difference between the estimated quantity and the actual quantity.
Admeasurement contracts are commonly used on civil engineering projects.
Rates are provided in the contractors tender, either as part of the priced bill of quantities, or within a schedule of rates. Then the actual quantities of work carried out are measured and the rates applied to those quantities. The contractor is paid for the actual work they have done. As a result, the quantities paid for may vary from the original estimates.
This is common in situations where the type of works required can be described in reasonable detail, but the amount cannot. For example, excavation works where the quantity of excavation required is difficult to assess until after the works have begun.
Where there is just a schedule of rates, rather than a bill of quantities, approximate quantities may be provided to allow the contractor to estimate the amount of work required, but there is no guarantee that that quantity will be required, and so appropriate rates are sometimes difficult to determine.
An advance payment, sometimes referred to as a down payment, or ex gratis payment, is when part of a contractual sum is paid in advance of the exchange, i.e. before any work has been done or goods supplied. Advance payments are typically recorded as prepaid expenses by the payer and recorded as assets on the balance sheet.
On a construction project, a contractor may request an advance payment to help them meet significant start up or procurement costs that may have to be incurred before construction begins. For example, where they have had to purchase high-value plant, equipment or materials specifically for the project. In these instances, the client should require an advanced payment bond. This secures the payment against default by the contractor.
A bad debt is a debt which a creditor realises will never be repaid, and which the creditor is not willing to embark on legal processes to retrieve. The loan is typically written off ie, it is assumed lost forever, never to be received.
Such a state of affairs may occur, for example, when the debtor is a company that has gone, or is about to go, into liquidation, or a heavily-indebted individual passes away.
The term insolvency' describes the inability of a debtor to pay its debts. In the United Kingdom, insolvent individuals are made 'bankrupt', while companies are put into 'liquidation' or 'administration'.
The precise definition of what constitutes a bad debt will depend on the country in which it exists.
Bonds are a means of protection against the non-performance of supplier. They are an undertaking by a bondsman or surety to make a payment to the client in the event of non-performance of the supplier. The cost of the bond is usually borne by the supplier, albeit, this is likely to be reflected in their tender price.
Bid bonds, also known as tender bonds, are rare in the UK, but can be a requirement of an international tender process. They are usually on-demand bonds submitted with a tender to secure the tender's commitment to commence the contract. The bond is partially or fully forfeited if the winning tenderer fails to execute the contract or meet other specified conditions.
The presence of a bid bond is intended to provide the client with the assurance that the tenderer has the financial capabilities of accepting the contract for the price quoted in their bid.
If the bond is partially or fully forfeited, the principal (typically the contractor) and the surety are jointly and severally liable for the bond, which includes any additional costs the client incurs in selecting and awarding another supplier. Often this is the difference between the lowest bid and the second-lowest bid.
However, there is the disadvantage that bid bonds can be open to abuse by the client and they may prevent smaller companies from tendering. Internationally, there have been cases of bonds 'disappearing' along with the client.
NB the UN Procurement Practitioner's Handbook, produced by the Interagency Procurement Working Group (IAPWG) in 2006 and updated in 2012, defines a bid bond or bid security as: 'A security from a supplier securing obligations resulting from a contract award with the intention to avoid: the withdrawal or modification of an offer after the deadline for submission of such documents; failure to sign the contract or failure to provide the required security for the performance of the contract after an offer has been accepted; or failure to comply with any other condition precedent to signing the contract specified in the solicitation documents.'
Capital Works Management Framework, Guidance Note, Glossary, Published by the Government of Ireland Department of Finance in 2009 suggests that: A bid bond is effectively a contract of guarantee whereby the guarantor or surety (authorised to do guarantee business) undertakes to pay damages to a second party, in this case the Employer, when the Contractor does not honour his tender. In essence, the guarantor undertakes to be answerable for losses suffered by the Employer if the Contractor withdraws following a bid. The Employer does not need to prove loss before calling in this bond. When a bond is called in, the Employer has a guarantee that funds up to the amount of the bond will be available to defray the Employers losses resulting from the Contractors default.
Introduction - The term landlord refers to a property owner who rents all or part of that property by lease or licence for a period of time.
The term landlord refers to a property owner who rents all or part of that property by lease or licence for a period of time.
There are different types of landlord, which can be determined by the actual time span for which a property is rented:
Portfolio landlord: This is a landlord who owns five or more properties.
Buy-to-let landlord: This is a landlord who buys a property in order to rent it out to tenants as a medium to long-term investment.
Let-to-buy landlord: This is a landlord who lets their existing property in order to facilitate a move to a new home they have bought. This can be a useful option when a property is proving difficult to sell.
Short-term landlord: This is a landlord who only lets their property for a short period of time, typically between a few weeks to up to 6 months.
Long-term landlord: For up to 7 years the landlord has repair obligations under Section 11 of the Landlord and Tenant Act. After 7 years they may not depending on the terms of the tenancy agreement.
An implied tenancy agreement, such as in the case of accommodation being part of a job (e.g. vicar, publican), means that the occupant should carry out the landlords duties.
The duties held by a landlord apply to a range of accommodation that has been rented out for less than 7 years:
Residential premises: Rented by local authorities, housing associations, private sector landlords, housing co-operatives, hostels.
Rooms: Let in bedsit accommodation, private households, bed-and-breakfast accommodation, hotels.
Rented holiday accommodation: Chalets, cottages, flats, caravans, narrow boats on waterways.
The landlord/tenant relationship differs from that of the freeholder/leaseholder. A freeholder owns the title absolute of a property and their details will appear on the land registry. A leaseholder uses the property for a specified period subject to conditions set out in the lease in return for the payment of rent.
The leaseholder may be permitted to sell the lease to another party or purchase the freehold (a process known as leasehold enfranchisement). They may also, in multi-occupancy properties, enter into collective ownership of the property freehold, known as commonhold.
Duties of landlords - The main responsibility of the landlord is to keep the property safe, free from health hazards and in a well-maintained condition. Any contents of the property must also be safe and should not cause injury or damage to tenants, neighbours or the public.
The main responsibility of the landlord is to keep the property safe, free from health hazards and in a well-maintained condition. Any contents of the property must also be safe and should not cause injury or damage to tenants, neighbours or the public.
The council can hold a landlord to account using the Housing Health and Safety Rating System (HHSRS).
The Landlord and Tenant Act - The Landlord and Tenant Act is the governing legislation for landlords and business tenants. A business tenants is somebody who rents or leases the place where they conduct their business.
The Landlord and Tenant Act is the governing legislation for landlords and business tenants. A business tenants is somebody who rents or leases the place where they conduct their business.
The legislation obliges the landlord to keep the property structure and exterior well maintained. The costs of repairs or maintenance undertaken during the tenancy period must be borne by the landlord, unless damage has been directly caused by the tenant. If landlords dont fulfill their legal obligations then local authorities have the power to prosecute.
The landlord is legally responsible for: -
The structure and exterior of the property. - Services such as lighting, heating, hot water installations and water supply.
Services such as lighting, heating, hot water installations and water supply.
Ventilation, serious damp. - Basins, sink, baths and showers.
Basins, sink, baths and showers. - Usually responsible for maintaining and repairing common areas, such as staircases.
Usually responsible for maintaining and repairing common areas, such as staircases.
Part II of the Act offers business tenants legal protection for the value they may have built up in a location which would be lost if they had to leave their premises when the lease expired; for example, if they have installed a lot of equipment, If the location is vital to their operation, if business continuity is important, and so on.
See Landlord and Tenant Act for more information.
The Gas Safety (Installation and Use) Regulations
The landlord must: -
Ensure the safe installation and maintenance of gas equipment by a registered engineer.
Have a registered engineer undertake an annual gas safety check on each appliance and flue.
Provide tenants with a copy of the gas safety check record before moving in.
Keep accurate records of all inspections, noting dates and repairs carried out.
The Electrical Equipment (Safety) Regulations - The landlord must:
The landlord must: -
Ensure that the electrical system, such as sockets and light fittings, is safe.
Ensure that all appliances, such as cookers and kettles, are safe.
The Smoke and Carbon Monoxide Alarm (England) Regulations
The landlord must: -
Provide fire alarms on each floor. - From 1 October 2015, private landlords in England have been required to fit carbon monoxide detectors in every room with a solid fuel burning appliance. Detectors must be tested at the start of each tenancy, and penalties for failure to comply can be up to 5,000.
From 1 October 2015, private landlords in England have been required to fit carbon monoxide detectors in every room with a solid fuel burning appliance. Detectors must be tested at the start of each tenancy, and penalties for failure to comply can be up to 5,000.
Ensure each prescribed alarm is in proper working order on the day the tenancy begins if it is a new tenancy.
Fire safety - The landlord must:
The landlord must: -
Ensure escape routes are accessible and in good condition.
Provide fire extinguishers where necessary. - In accordance with the Regulatory Reform (Fire Safety) Order, a fire risk assessment must be carried out to minimise the risk of fire.If the property is furnished, the landlord must ensure that furniture and furnishings comply with the guidelines set under the Furniture and Furnishings Fire and Safety Regulations.
In accordance with the Regulatory Reform (Fire Safety) Order, a fire risk assessment must be carried out to minimise the risk of fire.If the property is furnished, the landlord must ensure that furniture and furnishings comply with the guidelines set under the Furniture and Furnishings Fire and Safety Regulations.
NB: Some of these safety requirements were updated under the Homes (Fitness for Human Habitation) Act 2018.
Costs - There are a number of costs to a landlord when letting a property:
There are a number of costs to a landlord when letting a property:
Letting agent fees - Agencies help market the property, vet prospective tenants, collect and chase rent, and may also manage the maintenance of the property. The level of service determines the fee to be paid by the landlord.
Agencies help market the property, vet prospective tenants, collect and chase rent, and may also manage the maintenance of the property. The level of service determines the fee to be paid by the landlord.
Income tax and capital gains tax - Income tax must be paid on the rental income and the profit when selling the property may be subject to capital gains tax if the price has increased since the landlord purchased the property.
Income tax must be paid on the rental income and the profit when selling the property may be subject to capital gains tax if the price has increased since the landlord purchased the property.
Maintenance - The landlords obligations to maintain the property mean that they will bear the costs for cleaning, replacing damaged articles, repainting, replacing services, and so on.
The landlords obligations to maintain the property mean that they will bear the costs for cleaning, replacing damaged articles, repainting, replacing services, and so on.
Insurance - Buildings insurance protects against fire and flood damage. Contents insurance covers the house contents. Landlord liability insurance covers landlords in the event of a tenant suffering an injury in the house for which the landlord may be responsible.
Buildings insurance protects against fire and flood damage. Contents insurance covers the house contents. Landlord liability insurance covers landlords in the event of a tenant suffering an injury in the house for which the landlord may be responsible.
Unpaid rent - Landlords must budget to allow for a certain percentage of rental income over the course of a year going unpaid, either for non-payment by tenants or due to the property being empty between tenants.
Landlords must budget to allow for a certain percentage of rental income over the course of a year going unpaid, either for non-payment by tenants or due to the property being empty between tenants.
Rent - Rent is the sum of money paid by the tenant to the landlord on a weekly, monthly, or other basis. Periodic tenancies that continue on a weekly or monthly basis cannot be subject to more than one rent increase per year by the landlord without the tenants agreement.
Rent is the sum of money paid by the tenant to the landlord on a weekly, monthly, or other basis. Periodic tenancies that continue on a weekly or monthly basis cannot be subject to more than one rent increase per year by the landlord without the tenants agreement.
A fixed-term tenancy, which runs for a defined time period, allows the landlord to increase the rent only if the tenant agrees. Without agreement, the rent can only be increased when the fixed term ends and before it is renewed. However, virtually all commercial leases issued in the UK will contain a provision allowing the landlord to periodically adjust the rent payable by the tenant.
The following obligations apply to any tenancy: -
The landlord must get the tenants permission before the rent can be increased by more than previously agreed.
The rent increase must be fair, realistic, and not out of keeping with average local rents.
The procedure for increasing rent set out in the tenancy agreement must be adhered to.
Without such a procedure in the tenancy agreement, the rent can only be increased at the end of the fixed term.
If the tenancy is weekly or monthly the landlord must give a minimum of one months notice for rent increases. If the tenancy yearly then they must give 6 months notice.
Landlords can pursue eviction procedures if a tenant falls behind with rent payments.
Deposits are usually paid by new tenants to landlords to secure the property and provide security in the event of default, or damage to the property. If a home is rented on an assured shorthold tenancy (AST) that started after 6 April 2007, the landlord must put the deposit in a government-backed tenancy deposit scheme (TDP).
For more information, see Rent. -
Termination - It is possible for a landlord to terminate a tenancy by the service of a statutory notice which provides a termination date not less than 6 months or more than 12 months after the notice has been served. The landlord must also prove a statutory ground for possession. It may be necessary for a landlord to satisfy the Courts if matters cannot be agreed with the tenants.
It is possible for a landlord to terminate a tenancy by the service of a statutory notice which provides a termination date not less than 6 months or more than 12 months after the notice has been served. The landlord must also prove a statutory ground for possession. It may be necessary for a landlord to satisfy the Courts if matters cannot be agreed with the tenants.
A landlord cannot serve the notice if the tenant has reported issues at the property being 'revenge eviction' and a landlord cannot serve the notice within the first three months of the tenancy.
The landlord may have to pay compensation to a business tenant on obtaining possession of premises based on statutory grounds, which is calculated as a multiplier of the rateable value.
NB a Superior Landlord is the person or company for the time being who owns the interest in the property which gives him the right to possession of the premises at the end of the Landlord's lease of the property.
A contract notice is any notification that provides information about an upcoming construction contract. It is essentially an advertisement. Today, most contract notices appear online but they may also be published in the hard copy versions of professional or other journals.
The UK government publishes public contract notices on its website and in the Official Journal of the European Union (OJEU). The OJEU is the official on-line gazette of record for the EU. Publishing contract notices in the OJEU is required for public projects above a certain value.
Publishing contract notices in the OJEU is intended to open up public procurement and ensure the free movement of supplies, services and works within the EU. Private projects may also need to be published in the OJEU if they have been publicly subsidised.
Contracts posted in the OJEU may range from the supply of materials, to the installation of a school football pitch, to large multi-million-pound framework contracts for infrastructure. Details of the project will be provided to enable interested parties to ascertain whether the contract is of interest and how to pursue it.
The UK Governments Contract Finder provides a search engine for contract notices on government and agency projects worth more than 10,000. It divides project notices into public sector and supply chain, breaking opportunities down further into location and contract value.
In Scotland, public contract notices must be published on Public Contracts Scotland (PCS) which provides free access to contract opportunities. It has details of contracts with Scottish local authorities, NHS Scotland, the Scottish Government, agencies and non-departmental public bodies (NDPBs), higher and further education and emergency services. When published on PCS, the contract notice is also published in the OJEU.
Expert determination is a form of alternative dispute resolution in which an independent third party who is an expert in the subject to be considered is appointed to decide the dispute. The experts decision is binding on the parties, unless the parties agree otherwise at the outset.
Expert determination is particularly suited to valuation disputes or technical issues which can be determined by a technical expert, rather than detailed legal issues. It can also be used for issues such as rent reviews, insurance wording disputes, boundary disputes and so on. It is ideally suited to multi-party disputes because of its informality and flexibility.
The expert is someone the parties agree can act in that capacity. They can be selected prior to a dispute arising, or can be appointed by the relevant institute or association of the expert.
A lawyer may be appointed as the expert, or expert tribunals can be formed consisting of one lawyer and one expert, typically with the lawyer having the final say. This is particularly useful where there is a mixture of technical and legal issues to resolve.
Expert determination is generally simpler and cheaper than arbitration or court proceedings, and can be used as a short cut to a binding decision. Unlike arbitration, the expert does not need to refer back to the parties before making the decision.
Expert determination may be written into the parties contract as a means of resolving any disputes, or it may be used to resolve an existing dispute in preference to the system set out in the contract. It is often used in conjunction with another dispute resolution system, such as mediation. The parties are able to resolve parts of the dispute about which they would prefer not to mediate, thereby reducing the time taken and costs.
An escrow is a deed, bond or other engagement delivered to a third party to take effect upon a future condition and not till then, to be delivered to the grantee.
Escrow accounts are commonly used as holding accounts for construction project funds. They are usually set up by a representative or solicitor acting on behalf of one of the parties to an intended contractual agreement (usually the employer). The terms of the agreement or payment notices will state that payments must be protected, so as to provide security to the other party in the event of a payment default.
Escrow arrangements impact negatively on the employers cash flow since they must put funds aside in a designated account. However, this has the benefit of providing security to the contractor, and it will continue to earn interest for the employer throughout the course of the project. It will be paid out at a pre-agreed point, sometimes on practical completion, but usually on settlement of the final account.
If there is an interim payment made by the employer out of the escrow account they are obliged to top it up again. Failing to do this may give the contractor the right to suspend performance or to determine the contract.
It is very important that the escrow account agreement is drafted correctly with appropriate professional advice if required. It is particularly important to consider whether the payment provisions are valid as part of a construction contract. In the case of JB Leadbitter & Co. Ltd. v Hygrove Holdings Ltd. (2012), a payment clause in the escrow agreement was found by the Technology and Construction Court to be ineffective because it was a pay-when-paid clause. This type of clause had been outlawed by the Housing Grants, Construction and Regeneration Act 1996.
The Chartered Institute of Procurement & Supply (CIPS) Glossary of procurement terms, states: In the context of computer software, an escrow agreement involves the supplier placing a copy of the software source (original and updated) code (i.e. the raw form of the software design) with a third party. If the software supplier ceases trading, the purchaser will then be provided with the source code, which will enable them to continue to use and, where necessary, adapt and update the software (provided that they can appoint appropriately skilled personnel to do so).
Force account work, also known as work-by-force account, or time and material work, is a payment method for construction work where there is no existing agreement on cost.
In this case, the works are undertaken with the understanding that the client will pay the contractor according to the actual cost of their labour, materials, and equipment, with an additional percentage for overheads and a mark-up for profit.
It can be used when the contractor and client are unable to agree a unit price or lump sum amount, or if these methods are impracticable, for example, when the quantities and scope of work are unknown at the time of tendering, or for a change order requiring extra, unforeseen work identified after construction has already begun.
Force account work can permit the early start of construction work in critical areas, and can save staff time and overhead costs that would be required for contract package preparation, bidding, evaluation and the award of contracts.
However, it can leave both parties open to unknown costs. The client may not know the quantity, or rates of the works required, and the contractor may agree to very broad terms such as 'all costs' which can leave them struggling to make claims later in the project.
A 'cooling off period' is a length of time during which the purchaser of goods or services has the right to cancel the purchase and obtain a refund.
The Consumer Rights Directive came into force in 2014, to clarify cancellation rights. It harmonised the cooling off period for goods and services sold by distance or off-premises to 14 days from the date of delivery. This means that a purchaser is able to cancel and get a refund within 14 days if they arranged the purchase by phone, online, by mail order or somewhere else outside their business.
It also makes certain contracts void in circumstances where the contract has been made in the purchasers home or place of business and a cooling off period has not been given. If a business does not provide details of how to cancel, the cooling off period is extended by 14 days from the date on which they are eventually received.
However, a purchaser does not automatically get a cooling off period if they have requested something that needs to be specially-made, such as windows, or if it relates to urgent repairs or maintenance.
For goods that are ordered, the cooling off period begins:
The day after the delivery is made, if a single item (or several items delivered in one go) is ordered.
The day after the last item is delivered if a one-off order is placed for items that will have a spread-out delivery.
The day after the first delivery if an order is placed for several, spread-out deliveries of the same items.
As long as works have not begun, a purchaser can cancel the contract within 14 days. If the purchaser requested for the works to begin during the cooling off period then part of the agreed price will have to be paid, depending on how much has been completed at the time of the request to cancel. If the works are begun during the cooling off period without the purchasers approval, the purchaser will have the right to cancel with a full refund of costs.
NB Property Factors (Scotland) Act 2011, Code of Conduct for Property Factors, Laid before the Scottish Parliament by the Scottish Ministers under Section 14 of the Property Factors (Scotland) Act 2011 in January 2020, defines a cooling off period as: A set period of time after an arrangement is agreed between homeowners and a property factor during which the homeowners can terminate the contract without incurring any penalty notice that may apply.
Gazumping is a term used to describe a situation in which the seller of property accepts a verbal offer from a potential buyer but subsequently accepts an offer from another party. It can also be used to refer to a situation where the seller raises the asking price before formally signing a contract, after having verbally agreed a lower price.
Despite the practice often resulting in the potential buyer facing unrecoverable costs (such as survey costs, conveyancing fees, mortgage arrangement fees, etc.), gazumping is legal in England and Wales, as well as several other countries. This is because the exchange of contracts is something that takes place relatively late in the property buying process, following the property survey, the receipt of a mortgage offer, and so on, and as a result there is typically a delay of several weeks or even months between the verbal acceptance of the offer and it becoming legally binding.
During this period the seller may become tempted by a higher offer, although gazumping may not always be on the basis of financial matters. It can also refer to a situation in which a seller decides to reject an offer for some other reason, such as to accept another partys offer who may be able to complete the purchase more quickly, i.e. if they already have a mortgage offer in place, or are first-time buyers and so not part of a property chain.
In very broad terms, an 'owner' is a person or organisation who has the rightful title to something such as property, i.e. the property belongs to them.
A homeowner is a person who owns a home, whether an apartment or house. They may have fully paid for the home and own it outright, or they may still owe money for it: an individual who has a mortgage on a property is still regarded as the homeowner even if the mortgage has many years to run and much money is owed.
Homeowners do not have to reside in their properties: landlords are still homeowners even if they rent out their properties to other people.
Homeowners who have acquired their first home (whether outright or through a mortgage) are usually said to have taken their first step on the housing ladder. They are often referred to as 'first-time buyers', and a number of government schemes have been introduced in recent years to encourage and support their entry into the housing market.
It is also possible to be a homeowner jointly with other people (such as a partner) or through shared ownership schemes provided by housing associations, although this may be viewed by some as part-home ownership. Such schemes typically involve purchasing a share of a property (typically between 25%-75%). A mortgage is required for the share that is purchased, and rent is paid on the remainder.
The housing policies of the conservative Thatcher government of the 1980s were designed to increase home ownership throughout the UK and to decrease the number of households in rented accommodation. Owning your home was regarded by many conservatives as almost a basic right. Policies were therefore implemented to bring this about, such as right to buy where council tenants were given the right to buy their homes from the local authority often at prices that were well below market values.
More recently, the governments help to buy scheme is aimed at enabling first-time buyers get on the property ladder and become homeowners.
The term hourly rate refers to the amount of remuneration a worker/employee receives for each hour that they work. Those who are paid at an hourly rate can be described as doing time work, unlike salaried workers who are paid a fixed salary regardless of the amount of time they work. Hourly rates tend to apply to part-time and manual labour, particularly in construction where tradespeople and site labourers are often paid by the hour.
Construction sites can sometimes be fitted with a clocking-in device that monitors the precise time that operatives arrive and depart, allowing them to be paid by the minute, or it can be rounded up or down to the nearest half hour. Weekends, Bank Holidays and evening work can be paid at a higher hourly rate as an employee incentive.
Workers in the UK who are paid on an hourly rate must be paid at least the National Minimum Wage, which is calculated over the month for which they are paid. The minimum hourly rate is determined by the age of the employee and whether or not they are an apprentice. In order to get the National Minimum Wage, they must be at least school leaving age (16) and they must be 25 or over to be entitled to the National Living Wage.
Income tax is a compulsory deduction taken by the government from the earnings of individuals.
Individuals pay tax on their income but some types of income may be exempt.
Tax is payable on the following types of income:
Earnings from employment; - Profits made through being self-employed;
Profits made through being self-employed; - Some state benefits;
Some state benefits; - Most pensions, including state pensions, company and personal pensions and retirement annuities;
Most pensions, including state pensions, company and personal pensions and retirement annuities;
Rental income (although this may not apply in some cases of being a live-in landlord);
Job-related benefits, eg a company car, lunch allowance etc;
Income from a trust, and - Interest on savings over the stipulated savings allowance.
Interest on savings over the stipulated savings allowance.
As at 2019, income tax is not payable on:
A limited amount of income from self-employment - this is the trading allowance.
A limited amount of rental income from property (unless the Rent-a-Room Scheme is being used).
Income from tax-exempt accounts, e.g Individual Savings Accounts (ISAs) and National Savings Certificates.
Dividends from company shares under a dividends allowance.
Some state benefits. - Money won on premium bonds, the National Lottery or the Health Lottery.
Money won on premium bonds, the National Lottery or the Health Lottery.
Rent an individual receives from a lodger in their house that is below the Rent-a-Room limit and
Income Tax allowances and reliefs. - Most people in the UK get a 'personal allowance' of tax-free income. This is the part of their income which they do not have to pay tax on.
Most people in the UK get a 'personal allowance' of tax-free income. This is the part of their income which they do not have to pay tax on.
The majority of people pay income tax through a system called PAYE (Pay As You Earn) which is used by employers and pension providers to deduct tax and National Insurance Contributions (NIC) directly out of wages and pensions. It is an automatic process and spares many people the complexity of calculating what their tax should be.
Indirect costs (or indirect spend) are those costs that are necessary to keep a process or project running, but which do not vary directly with the volume of goods or services produced and are not easily attributable to a particular process or project. This might for example include; rent, insurance, advertising and marketing and so on. These types of indirect costs may be referred to as overheads.
This is as opposed to direct costs, which are those costs incurred directly by production and include items such as raw materials, labour, equipment, power and so on. Direct costs can be traced and are attributed to a cost object which may be a product, department, cost centre or project.
So, indirect costs do not vary directly with production levels, whereas direct costs remain dependent on production levels and will vary when production is increased or decreased.
An instruction is a request, order or command from one party to another. Typically, the person issuing the instruction requests a course of action or a sequence of events to be implemented by the party that has received the instruction. Instructions usually have to obeyed or implemented.
In construction, consultants, clients and contractors issue instructions continually to ensure buildings are completed as specified, on time and to budget. The most obvious example is the architects instruction (AI) or 'contract administrators instruction. This is an instruction in written form, usually to the contractor which may be given:
To vary the works. - To postpone the works.
To postpone the works. - To remedy workmanship, goods or materials which are not in accordance with the contract.
To remedy workmanship, goods or materials which are not in accordance with the contract.
To sanction a variation made by the contractor.
In relation to the expenditure of provisional sums.
To open up work for inspection. - To carry out tests.
To carry out tests. - To exclude persons from the site.
To exclude persons from the site. - Any other instructions empowered by the contract.
Any other instructions empowered by the contract. - The contractor must comply with the instruction within certain limitations, but has the right to reasonably object.
The contractor must comply with the instruction within certain limitations, but has the right to reasonably object.
An internal contract is one that exists between a principal and an agent, i.e. the agent is legally appointed to act on its behalf. An external contract is one that exists between a principal and a third party, usually with the facilitation of an agent.
A service level agreement (SLA) is a common type of internal contract, which sets out what a supplier/service provider is required to provide to the client, and to what standard.
For more information, see Service level agreement.
Internal contracts can be prepared within an organisation, i.e. between teams or departments, or used for the outsourcing of services, such as facilities management, IT services, and so on.
Some of the elements typically required in an internal contract include:
Name of the principal/client. - Name of the agent/supplier.
Name of the agent/supplier. - The product and/or services to be provided.
The product and/or services to be provided.
Start date. - Estimate of the elapsed time required. (For SLAs, this takes the form of a renewal date.)
Estimate of the elapsed time required. (For SLAs, this takes the form of a renewal date.)
Price and the terms of payment. - Clients accountabilities, i.e. what the client must do/provide in order for the supplier to successfully perform the contract.
Clients accountabilities, i.e. what the client must do/provide in order for the supplier to successfully perform the contract.
Risks and assumptions about external dependencies that may hinder the performance of the contract.
Integrated Project Insurance (IPI) is an innovative insurance product which gives the IPI model its name. It collectively insures the client and all the other Alliance partners: consultants, specialists, manufacturers, construction managers and their supply chains. In particular it replaces liability-driven professional indemnity insurance (which requires proof of fault before responding) with financial loss cover where the outturn cost above the target cost plus pain-share is insured.
But IPI is only available as part of the IPI Model which is founded on the principle of a new and transparent partnership with insurers. In granting cover the insurers will have had regard to the following fundamental principles which the Alliance members (including the client) intend to comply with when undertaking the project:
The Alliance members embrace fully integrated collaborative working and act in a spirit of mutual trust and co-operation at every stage of the project and comply with the alliance principles agreed in the Alliance contract.
There are mutual no-blame/no claim undertakings; and whatever percentage share you take of gain, the same must be your share of pain.
All decisions are taken on a best for project basis.
There is independent facilitation and financial/technical independent risk assurance at all stages of the project.
The performance of the Alliance members will be measured against agreed success criteria.
The Alliance members will work on an open book basis and seek ways of driving down costs and maximising gain-share by over-achieving against the success criteria.
There will be no distinction or barriers between the design and construction elements of the project as all members will be working as a single integrated team.
In parallel with the Alliance members and their supply chains waiving rights to claim against each other, the insurers waive rights of subrogation against all the insured at every tier.
Under the IPI model the emphasis is on collective and transparent governance:
When the IPT (Integrated Project Team) is satisfied that its preferred project solution and target cost will meet the strategic brief in accordance with the success criteria and within the pre-agreed investment target, it puts it forward for approval.
The IF (Independent Facilitator) , and TIRA (Technical Independent Risk Assuror) and FIRA (Financial Independent Risk Assurer), if respectively satisfied that the IPT is indeed collaborative and that its preferred project solution and target cost have adequate allowance for technical and financial risks, give endorsement to the client and insurers.
When accepted by the client and insurers, this project solution and target cost are insured under the IPI Policy, and the TIRA/FIRA appointments are novated to the insurers.
The IF and TIRA/FIRA remain involved and engage openly and collaboratively with the IPT during design development, procurement, construction and completion/proving. If the IPT does not adequately resolve issues of concern raised by the independent assurers, the assurance team reports to the Alliance Board and, if they are still not satisfied with the solution put forward, have the right to recommend to the insurers that the associated risk be excluded from coverage under the policy. This exclusion may relate to the target cost up to completion or the latent defects cover thereafter.
By virtue of the involvement of the IF, TIRA and FIRA, insurers have a close project relationship under the IPI Model. In essence they can have confidence based on independent expert advice that:
the members of the IPT and their supply chains are suitable
they are adopting behaviours which will result in the efficient use of resources
project solutions and target costs provide adequately for technical and financial risks
a realistic and achievable project execution plan is being followed
outturn costs are necessarily incurred - and they will receive early alerts to problems and potential overspends, and can participate in decisions over mitigation.
and they will receive early alerts to problems and potential overspends, and can participate in decisions over mitigation.
In return, insurers are prepared to agree a wider range of cover than under traditional project policies; they have an overview of all potential risks, and are in a better position to understand them. IPI insurers have been carefully selected by the brokers; their contracts are subject to utmost good faith; and they are expected to recognise and fund overspends promptly after they have been identified and verified by the FIRA.
Until the IPI product is fully established and a much simplified integrated format can be developed, the IPI policy comprises:
Section 1: Construction All Risks (including Terrorism Extension)
Section 2: Third Party Liability (including Non-Negligent Liability)
Section 3: Delay in Completion (resulting from damage under Section 1)
Section 4: Financial Loss cover - and
and -
Latent Defects cover (for 12 years) a no fault commercial latent defects insurance policy.
This use of known products is seen as an advantage in the early days of IPI as those who will benefit from the cover are better able to relate to the protection they are used to seeing.
The financial loss cover under the IPI policy has an agreed cap (limit of insurers indemnity), and its exclusions are limited to normal industry exclusions which are:
nuclear and war risks and sonic bang - wilful default
wilful default - employers (clients) risks
employers (clients) risks - change of law
change of law - any other specific exclusions relating to the particular circumstances of the project (e.g. MOD security issues).
any other specific exclusions relating to the particular circumstances of the project (e.g. MOD security issues).
Under the IPI Model each Alliance member participating in the gain-share/pain-share mechanism in the Alliance contract knows that his loss is limited to his pre-agreed share of the maximum pain-share. The benefits deriving from this policy should ensure that all parties concerned are open and honest about their allowances (usually in overheads) for omnibus insurances, and exclude them from the build-up of their target and actual overhead costs for the project so as to avoid cost duplication.
Under a study undertaken for the then Office of Government Commerce the combined premium cost of traditional construction all risks, public liability and professional indemnity insurances on a commercial development throughout the supply chain amounted to 2.5%. This was based on normal risks, and excluded excesses. The cost of IPI has been fixed at 2.5% of the project cost, which is better than cost-neutral because it also includes:
independent facilitation and technical/financial risk assurance - cost overrun cover (instead of professional indemnity)
cost overrun cover (instead of professional indemnity)
latent defects cover. - It also saves the cost of taking out collateral warranties. There is therefore no cost penalty for a client adopting IPI.
It also saves the cost of taking out collateral warranties. There is therefore no cost penalty for a client adopting IPI.
For completeness: due to its inherent variability, the study excluded insurances associated with feasibility or pre-project planning activities. The essential pre-initiation activity under the IPI model includes the assistance and support to the client in selecting and appointing the members of the Alliance and securing their understanding and commitment to the strategic brief and success criteria: this variable element is covered on a time-charge basis. The 2.5% fee then commences with a pre-inception instalment, with the balance payable upon inception of the IPI policy; because locality is also variable, fees are subject to reimbursement of expenses.
A letter of award, also known as an award letter, is sent by a client/employer as written confirmation that a tenderer has been successful and will be awarded a contract.
The letter forms part of the contract award, which is the process of formally notifying a tenderer that they have been selected as the supplier for a particular contract. It will usually be sent out together with letters to unsuccessful tenderers.
The letter will typically contain details of the amount of the award, the date of the award, and when the contract will be signed. A notice to proceed may also be included detailing the date on which a contractor may begin work.
On public projects, the despatch of a letter of award signifies the start of the Alcatel (standstill) period in the procurement process. This allows unsuccessful tenderers the chance to obtain more information on the award of the contract so they can take appropriate action if they believe they have been unfairly treated.
As such it may be necessary for a letter of award to avoid committing to accepting the tender, since this can be taken to be binding. Rather, the aim of the letter is to give the successful bidder reassurance, and to allow them to begin preparations, whilst refraining from any commitment to legally binding obligations.
As a result, a letter of award may be referred as a 'letter of intent to award' or it may include caveats.
NB A letter of intent is a document expressing an intention to enter into a contract at a future date but creating no contractual relationship until that future contract has been entered into. This may be necessary when suppliers are incurring costs and overheads and can be used as an interim arrangement prior to a formal contract being executed. For more information see: Letter of intent.
A letter of intent is a document expressing an intention to enter into a contract at a future date but creates no contractual relationship until that future contract has been entered into. A letter of intent is not an 'agreement to agree'.
It is important to bear in mind that 'letter of intent' is a term of commercial convenience and not a term having a substantive legal meaning, as for example 'subject to contract. Each letter of intent must be construed on its own particular meaning.
It is suggested that the legal effect of a letter of intent may fall into one or more of the following categories:
The expression of an intention to enter into a contract at a future date which does not give rise to any legal obligation, whether in contract or quasi ex-contractu (as if from a contract) on a quantum meruit (a reasonable amount for labour and materials, payable even in the absence of an enforceable agreement); or
The expression of an intention to enter into a contract at a future date which does not give rise to any liability in contract but does not exclude or negate a right to recover reasonable expenditure on a quantum meruit; or
The creation of a conditional or ancillary contractual obligation which may, but not necessarily will, be subsumed by a wider contractual obligation upon formal contracts being exchanged; or
A legally binding executory contract in that the letter of intent is an offer capable of being accepted or is the acceptance of an offer.
Letters of intent are most commonly sent at a time when it is anticipated that the recipient will be incurring costs and overheads. They can be used as an interim arrangement to mobilise construction prior to a formal contract being executed, but they should never be seen as an alternative to a full contract and should place a limit on expenditure and the clients liability prior to the contract being put in place.
For a letter of intent to be binding, there must be the three essential elements of a contract; agreement, intention and consideration.
A lump sum contract (or stipulated sum contract) is the traditional means of procuring construction, and still the most common form of construction contract. Under a lump sum contract, a single lump sum price for all the works is agreed before the works begin.
It is defined in the CIOB Code of Estimating Practice as, a fixed price contract where contractors undertake to be responsible for executing the complete contract work for a stated total sum of money.
This is generally appropriate where the project is well defined, when tenders are sought, and significant changes to requirements are unlikely. This means that the contractor is able to accurately price the works they are being asked to carry out.
Lump sum contracts might be less appropriate where speed is important, or where the nature of the works is not well defined. Other forms of contract that might be more appropriate in such circumstances include measurement contracts (used where the works can be described in reasonable detail, but the amount cannot), cost reimbursement contracts (used where the nature of the works cannot be properly defined at the outset, often used where an immediate start on site is required), target cost contracts, and so on (see Procurement route for more information).
Lump sum contracts apportion more risk to the contractor than some other forms of contract, as there are fewer mechanisms to allow them to vary their price, and they give the client some certainty about the likely cost of the works. The tender process will tend to be slower than for other forms of contract and preparing a tender may be more expensive for the contractor.
However, a lump sum contract does not give all the project risk to the contractor, and it is not a fixed price, or even a guaranteed maximum price. The price of a lump sum contract can change.
Mechanisms for varying the contract sum on a lump sum contract include:
Variations: These are changes in the nature of the works. Most contracts will contain provision for the architect or contract administrator to issue instructions to vary the design, quantities, quality, sequence or working conditions.
Relevant events: A relevant event may be caused by the client (for example, failure to supply goods or instructions), or may be a neutral event (such as exceptionally adverse weather) and may result in a claim for loss and expense by the contractor.
Provisional sums: An allowance for a specific element of the works that is not defined in enough detail for tenderers to price.
Fluctuations: A mechanism for dealing with inflation on projects that may last for several years where the contractor tenders based on current prices and then the contract makes provisions for the contractor to be reimbursed for price changes over the duration of the project.
Payments to nominated sub-contractors or nominated suppliers. - Statutory fees.
Statutory fees. - Payments relating to the opening up works for inspection and testing.
Payments relating to the opening up works for inspection and testing.
The better defined the works are when the contract is agreed, the less likely it is that the contract sum will change.
It is important to recognise that a truly 'fixed' price contract would not necessarily be in the interests of the client as it would require that the contractor price risks over which they may have no control, and which might not arise. It would also give very little scope for the client to alter their requirements.
Advantages of lump sum contracts: -
Client's risk is minimal. - Fewer variations.
Fewer variations. - The client can arrange capital according to the payment plan.
The client can arrange capital according to the payment plan.
Contractor's cash flow is predictable. - The tendering process is more transparent and impartial.
The tendering process is more transparent and impartial.
Disadvantages of lump sum contracts: -
Contractors risk is high (poor productivity and mismanagement can lead the project into a loss).
Poor details and specs in the design can lead to project disputes.
Delays in the client's financing can delay the project.
The design should be complete and available before the pre-contract process.
Procurement times can be long. -
Quantity is a measurement of a physical entity in units that depend on the nature of that entity. Therefore, quantity indicates how much of something exists, existed or will exist.
In construction, measured quantities typically form part of a bill of quantities (BoQ) and indicate how much of something will be required to construct a building or part of a building.
Usually prepared by a quantity surveyor (QS), the BoQ provides project-specific, measured quantities of the items of work identified by the drawings and specifications (which form part of the tender documentation). For example, in a traditional building, the BoQ will contain measured quantities for each item that goes to make up the final construction e.g bricks, doors, ironmongery, floor tiles, roof slates, etc. This means that potential tenderers know exactly how much of a given quantity will be required for the work and so they can price for it. This creates a level playing field as all tenderers are pricing for the same measured quantities which allows the client to make easy comparisons between the bids.
Measured quantities are typically expressed in number (e.g door handles), length (e.g handrails, kerbs), area (e.g floor tiles, plaster), volume (e.g concrete) or weight (e.g gravel).
When prices have been entered by a tenderer beside each measured quantity in a BoQ, this constitutes the tenderers offer.
Not providing measured quantities would require that the various tenderers on a project take off the quantities themselves. With numerous tenderers with possibly different methodologies, as well as human error creeping in, the quantities taken off would vary, thus making the clients job in comparing the tenders that much harder.
The New Rules of Measurement (NRM) are published by the Royal Institution of Chartered Surveyors' (RICS) Quantity Surveying and Construction Professional Group. They provide a standard set of measurement rules for estimating, cost planning, procurement and whole-life costing for construction projects. Adopting a standard methodology such as NRM facilitates consistency and benchmarking and helps avoid disputes.
NRM is a suite of documents, comprising three volumes; NRM1, NRM2 and NRM3.
Fore more information see: New rules of measurement.
In some circumstances, it may be difficult to determine exact quantities, for example early in the development of a project. In this case approximate quantities may be estimated. These should be accompanied by a schedule of the assumptions made in determining the approximate quantities.
Adhesives are bonding agents used to join materials by glueing.Adhesives can be used in construction in many situations:
Carpet laying. - Ceramic tiles.
Ceramic tiles. - Countertop lamination.
Countertop lamination. - Drywall lamination.
Drywall lamination. - Flooring underlay.
Flooring underlay. - Glulam.
Glulam. - Heating, ventilation, air conditioning connections.
Heating, ventilation, air conditioning connections. - Timber jointing.
Timber jointing. - Manufactured housing.
Manufactured housing. - Pre-fabricated panels.
Pre-fabricated panels. - Resilient flooring.
Resilient flooring. - Roofing.
Roofing. - Wall coverings.
Wall coverings. -
The most common types of adhesive are as follows:
PVA (polyvinyl acetate): A general purpose woodwork glue, with some water resistant properties.
Synthetic resin: A strong water-resistant woodwork glue.
Epoxy resin: Used for metals and plastics.
Acrylic cement: Used for acrylic and some types of plastic. The adhesive melts the surface of the plastic and fuses it together.
Casein: Made from sour milk. A cold setting adhesive in the form of a powder which is mixed with water.
Urea formaldehyde: A cold setting resin glue. Although moisture resistant, it is usually restricted to timber members used in dry, unexposed conditions as it loses strength after prolonged exposure to water or heat.
Resorcinol formaldehyde: A cold setting glue that is suitable for timber members used in external situations. Will set at temperatures down to 15C and does not lose strength at high temperatures.
Phenol formaldehyde: A warm setting adhesive that requires a temperature of above around 86C to set.
Introduction - An actuator is a component of a machine that is responsible for moving or controlling a mechanism or system, by converting energy into motion. It is the mechanism by which a control system acts upon an environment. It can be a simple system, such as fixed or electronic, or software-based, such as robot control.
An actuator is a component of a machine that is responsible for moving or controlling a mechanism or system, by converting energy into motion. It is the mechanism by which a control system acts upon an environment. It can be a simple system, such as fixed or electronic, or software-based, such as robot control.
Actuators are often used in manufacturing or industrial applications, and in devices such as pumps, switches and valves. They have also been used in innovative adaptive structures.
Motion is usually created by air, electricity or liquid. The types of motion created by actuators are linear, rotary or oscillatory.
The most common types of actuator are as follows:
Pneumatic - Pneumatic actuators convert energy formed by a vacuum or compressed air at high pressure into either linear or rotary motion. The advantage of this type of actuator is that has a quick response time as the power source doesnt need to be stored in reserve. Large forces can be produced from relatively small pressure changes.
Pneumatic actuators convert energy formed by a vacuum or compressed air at high pressure into either linear or rotary motion. The advantage of this type of actuator is that has a quick response time as the power source doesnt need to be stored in reserve. Large forces can be produced from relatively small pressure changes.
Hydraulic - Hydraulic actuators consist of a cylinder or fluid motor that uses hydraulic power to drive mechanical operation. The motion output can be linear, rotary or oscillatory. The cylinder consists of a hollow tube along which a piston can slide. Despite having limited acceleration, a hydraulic actuator can exert considerable force as liquids are virtually impossible to compress.
Hydraulic actuators consist of a cylinder or fluid motor that uses hydraulic power to drive mechanical operation. The motion output can be linear, rotary or oscillatory. The cylinder consists of a hollow tube along which a piston can slide. Despite having limited acceleration, a hydraulic actuator can exert considerable force as liquids are virtually impossible to compress.
Hydraulic actuators can be either single acting when fluid pressure is applied to one side of the piston only or double acting where pressure is applied on both sides.
Electric - An electric actuator is powered by electrical energy converted by a motor. Electrical energy is used to actuate equipment such as multi-turn valves. Its advantage is that it is one of the cleanest forms of actuator as no oil is required.
An electric actuator is powered by electrical energy converted by a motor. Electrical energy is used to actuate equipment such as multi-turn valves. Its advantage is that it is one of the cleanest forms of actuator as no oil is required.
Thermal or magnetic - These actuators tend to be compact, lightweight and with high power density. They are actuated by applying thermal or magnetic energy.
These actuators tend to be compact, lightweight and with high power density. They are actuated by applying thermal or magnetic energy.
Mechanical - A mechanical actuator functions by converting rotary motion into linear motion to execute movement. It involves gears, rails, pulleys, chains and other devices to operate. An example is a rack and pinion mechanism.
A mechanical actuator functions by converting rotary motion into linear motion to execute movement. It involves gears, rails, pulleys, chains and other devices to operate. An example is a rack and pinion mechanism.
An admixture is a substance which can be added to concrete to achieve or modify its properties. Admixtures are added to the concrete, in addition to cement, water and aggregate, typically immediately before or during the mixing process.
Admixtures can be used to reduce the cost of building with concrete, or to ensure certain required properties or quality of the cured concrete. If problems arise with the concrete during the construction process, admixtures can be used as an emergency measure to try and prevent failure. In addition, some of the main functions of using admixtures include:
Water-reducing: Can reduce the water content needed to reach a required slump by 5-10%.
Retarding: Slow the setting rate of concrete, keeping it workable and are often used to counteract the accelerating effect of hot weather.
Accelerating: Increase the rate of early-strength development and reduce the time required for curing.
Superplasticizers: Can reduce water content by 12-30% to make a highly fluid but workable form of concrete known as flowing concrete.
Corrosion-inhibiting: Used to slow the corrosion of reinforcing steel in the concrete. Often used in marine structures, bridges and others that will be exposed to chloride in high quantities.
Air-entraining: Small bubbles of air formed uniformly through the concrete mix to increase cohesion and resistance to freeze-thaw degradation.
Improving the curing of the concrete. - Providing waterproofing properties.
Providing waterproofing properties. - To improve hardness.
To improve hardness. - Providing colour.
Providing colour. - Offsetting or reducing a chemical reaction.
Offsetting or reducing a chemical reaction. - Aeration to reduce the weight.
Aeration to reduce the weight. - Offsetting or reducing shrinkage.
Offsetting or reducing shrinkage. - Dispersing cement particles when mixed with water.
Dispersing cement particles when mixed with water. - Alkali-silica reactivity reduction.
Alkali-silica reactivity reduction. - Admixtures are usually provided in a liquid form. Some admixtures, such as pigments, pumping aids and expansive agents, are typically added manually from pre-measured containers as the amount used is very small.
Admixtures are usually provided in a liquid form. Some admixtures, such as pigments, pumping aids and expansive agents, are typically added manually from pre-measured containers as the amount used is very small.
A louvre (pronounced loover) comprises narrow, sloping slats held in a frame and typically used to cover a vertical opening such as a window or an air vent. They provide screening and can also prevent access, shade from the sun and provide protection against wind and rain.
Louvres can be made of wood, glass and metal particularly aluminium. In a window, the louvres may form part of a shutter (usually timber) applied either inside or outside of the window opening. The latter are very common in hot countries as they can allow air to circulate yet provide a degree of solar shading. They can also afford privacy to those on the inside.
Where the slats of a louvre are adjustable, it is termed a jalousie. A jalousie may form an entire window in which case it may comprise a series of adjustable, horizontal glass slats. In the UK however, it is more common to have a narrow jalousie of three or four louvres adjustable for ventilation above a much larger fixed pane of glass.
Internal louvred wooden shutters have become popular in the UK as they can form attractive architectural elements in their own right; they may incorporate adjustable slats, give excellent screening and provide an attractive alternative to the ubiquitous net curtain. they can also act as a light shelf, reflecting sunlight deep into a building's interior.
Aluminium louvred panels are sometimes fixed externally to building facades to reduce glare to the building occupants. Freestanding louvred screens may also be used to mask unsightly areas, such refuse storage areas, mechanical plant and so on.
Building acoustics is the science of controlling noise in buildings. This includes the minimisation of noise transmission from one space to another and the control of the characteristics of sound within spaces themselves.
Building acoustics are an important consideration in the design, operation and construction of most buildings, and can have a significant impact on health and wellbeing, communication and productivity. They can be particularly significant in spaces such as concert halls, recording studios, lecture theatres, and so on, where the quality of sound and its intelligibility are very important.
Building acoustics can be influenced by: -
The geometry and volume of a space. - The sound absorption, transmission and reflection characteristics of surfaces enclosing the space and within the space.
The sound absorption, transmission and reflection characteristics of surfaces enclosing the space and within the space.
The sound absorption, transmission and reflection characteristics of materials separating spaces.
The generation of sound inside or outside the space.
Airborne sound transmission. - Impact noise.
Impact noise. -
Sound absorption is the loss of sound energy when sound waves comes into contact with an absorbent material such as ceilings, walls, floors and other objects, as a result of which, the sound is not reflected back into the space.
Sound absorbent materials can be used to create a suitable acoustic environment within a space by reducing the reverberation time. Reverberation affects the way a space 'sounds'. A long reverberation time can make a room sound loud and noisy and causes speech to sound muffled and muddy. Rooms designed for speech therefore typically have a short reverberation time of less than 1 second. Conversely, a longer reverberation time can enhance a music hall by adding richness, depth and warmth to music.
Sound absorption can be a particularly important factor for spaces such as:
Sports halls. - Schools.
Schools. - Recording studios.
Recording studios. - Lecture theatres.
Lecture theatres. - Concert venues, cinemas and theatres.
Concert venues, cinemas and theatres. - Generally, sound absorption is applied in the form of treatment to floors, walls, ceilings, partition surfaces and objects such as chairs or bookshelves. The use of sound absorbing screens is also becoming more common.
Generally, sound absorption is applied in the form of treatment to floors, walls, ceilings, partition surfaces and objects such as chairs or bookshelves. The use of sound absorbing screens is also becoming more common.
Sound absorbers can be divided into three main categories:
Porous absorbents. - Resonance absorbents.
Resonance absorbents. - Single absorbents.
Single absorbents. - Porous absorbents conventionally take two forms; fibrous materials or open-celled foam. Fibrous materials absorb sound as sound waves force the fibres to bend and this bending of the fibres generates heat. The conversion of acoustic energy into heat energy results in the sound effectively being absorbed. In the case of open-celled foam, the air movement resulting from sound waves pushes air particles through the narrow passages which in turn generate a viscous loss along with heat.
Porous absorbents conventionally take two forms; fibrous materials or open-celled foam. Fibrous materials absorb sound as sound waves force the fibres to bend and this bending of the fibres generates heat. The conversion of acoustic energy into heat energy results in the sound effectively being absorbed. In the case of open-celled foam, the air movement resulting from sound waves pushes air particles through the narrow passages which in turn generate a viscous loss along with heat.
Usually a materials thickness has the greatest impact on its sound absorbing qualities. The thickness of materials can be compensated for with air space behind a wall panel or acoustic ceiling to improve performance at lower frequencies.
It is generally better to not include an airtight layer on the surface, such as a vapour barrier or paint layer, as this may reduce the sound absorbing qualities. However, architecturally, fibrous materials and open celled foams are not always considered attractive or robust. It is common therefore to cover these materials with an acoustically transparent finish such as a tissue, cloth or slatted wood, or with perforated materials such as wood, metal, plasterboard and so on.
Resonance absorbents consist of a mechanical or acoustic oscillation system, such as membrane absorbers, where there is a solid plate with a tight air space behind. Absorption reaches its maximum at the resonance frequency. The cavity can be filled with a porous material, to broaden the absorption over the range of frequency.
Single absorbers can be tables, chairs or other objects.
The sound absorbing characteristics of acoustical materials varies significantly with frequency. Low frequency sounds, below 500 Hz, tend to be more difficult to absorb whereas high frequencies sounds, above 500 Hz, are easier to absorb.
A material's sound absorbing properties can be expressed by the sound absorption coefficient, alpha, as a function of frequency. Alpha ranges from 0 (total reflection) to 1.00 (total absorption).
The term 'cladding' refers to components that are attached to the primary structure of a building to form non-structural, external surfaces. This is as opposed to buildings in which the external surfaces are formed by structural elements, such as masonry walls, or applied surfaces such as render.
Building Safety Fund for the remediation of non-ACM Cladding Systems (England only) Registration prospectus, published by MHCLG in May 2020 suggests that: 'A cladding system includes the components that are attached to the primary structure of a building to form a non-structural external surface. The cladding system includes the weather-exposed outer layer or screen, fillers. Insulation, membranes, brackets, cavity barriers, flashing, fixings, gaskets and sealants.'
Whilst cladding is generally attached to the structure of the building, it typically does not contribute to its stability. However, cladding does play a structural role, transferring wind loads, impact loads, snow loads and its own self-weight back to the structural framework.
In particular, wind causes positive and negative pressure on the surface of buildings and cladding must have sufficient strength and stiffness to resist this load, both in terms of the type of cladding selected and its connections back to the structure.
Cladding is needed to: -
Create a controlled internal environment. - Protect the building from external conditions.
Protect the building from external conditions. - Provide privacy and security.
Provide privacy and security. - Prevent the transmission of sound.
Prevent the transmission of sound. - Provide thermal insulation.
Provide thermal insulation. - Create an external facade.
Create an external facade. - Prevent the spread of fire.
Prevent the spread of fire. - Generate an 'airtight' building envelope.
Generate an 'airtight' building envelope. - Providing openings for access, daylight and ventilation.
Providing openings for access, daylight and ventilation.
Cladding is often prefabricated in panels that are attached to the structural frame of the building, and some cladding systems can be purchased 'off the shelf'.
Cladding systems may include additional components, such as windows, doors, gutters, roof lights, vents and so on.
The nature of cladding selected for a particular building will depend on considerations such as:
How the building is going to be used.
Internal and external conditions. - Durability.
Durability. - Local context.
Local context. - Planning requirements.
Planning requirements. - Building regulations requirements.
Building regulations requirements. - Accessibility and buildability.
Accessibility and buildability. - Appearance.
Appearance. - Availability.
Availability. - Budget.
Budget. - Maintenance requirements.
Maintenance requirements. - Structural requirements.
Structural requirements. - High-quality, well-designed, properly-installed cladding can help maximise thermal performance, minimise air leakage, and optimise natural daylighting. This can help reduce the need for mechanical and electrical building services, and so improve energy efficiency and lower capital and running costs.
High-quality, well-designed, properly-installed cladding can help maximise thermal performance, minimise air leakage, and optimise natural daylighting. This can help reduce the need for mechanical and electrical building services, and so improve energy efficiency and lower capital and running costs.
Poor design detailing or installation may compromise cladding performance and can result in safety problems such as cladding collapse or cladding panels pulling away from the structure.
When selecting or designing a suitable cladding, designers should pay particular attention to:
Design detailing. - Control of air leakage.
Control of air leakage. - Control of condensation.
Control of condensation. - Integrity and continuity of Insulation.
Integrity and continuity of Insulation. - Prevention of water penetration, or provision of drainage.
Prevention of water penetration, or provision of drainage.
Control of thermal movement. - Spread of fire.
Spread of fire. - Ease of installation.
Ease of installation. - External attachments and fixings.
External attachments and fixings. - Cleaning.
Cleaning. - Maintenance, remedial work and renewal.
Maintenance, remedial work and renewal. - Resilience, strength and durability.
Resilience, strength and durability. -
Some of the more common types of cladding are described below.
Curtain walling - Curtain wall systems are a non-structural cladding system for the external walls of buildings. They are generally associated with large, multi-storey buildings. Typically curtain wall systems comprise a lightweight aluminium frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as 'glazing' whether or not they are made of glass.
Curtain wall systems are a non-structural cladding system for the external walls of buildings. They are generally associated with large, multi-storey buildings. Typically curtain wall systems comprise a lightweight aluminium frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as 'glazing' whether or not they are made of glass.
See Curtain wall systems for more information. -
Sandwich panels - Sandwich panels (sometimes referred to as composite panels or structural insulating panels (SIP)) consist of two layers of a rigid material bonded to either side of a lightweight core, so that the three components act as a composite.
Sandwich panels (sometimes referred to as composite panels or structural insulating panels (SIP)) consist of two layers of a rigid material bonded to either side of a lightweight core, so that the three components act as a composite.
See Sandwich panel and Metal composite panels for more information.
Patent glazing - The term patent glazing refers to a non-load bearing, two-edge support cladding system. Patent glazing bars provide continuous support along two edges of glazing infill panels (rather than four-edge curtain walling), and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
The term patent glazing refers to a non-load bearing, two-edge support cladding system. Patent glazing bars provide continuous support along two edges of glazing infill panels (rather than four-edge curtain walling), and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
See Patent glazing for more information. -
Rainscreen - A rainscreen (sometimes referred to as a drained and ventilated or pressure-equalised faade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
A rainscreen (sometimes referred to as a drained and ventilated or pressure-equalised faade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
See Rainscreen for more information. -
Timber cladding - One of the most popular methods of cladding is through the use of timber softwoods, such as western red cedar. This type of wood is relatively knot-free and has a natural resistance to decay and moisture. It can be readily stained or painted and altered to create a range of profiles.
One of the most popular methods of cladding is through the use of timber softwoods, such as western red cedar. This type of wood is relatively knot-free and has a natural resistance to decay and moisture. It can be readily stained or painted and altered to create a range of profiles.
Hardwoods can also be used including oak and sweet chestnut. Both of which contain high tannin levels which can result in leaching and streaking after exposure to the elements. Thermally modified timbers are also being used such as Kebony, Keywood, Platowood and ThermoWood. These softwoods are heated to high temperatures which removes moisture and resins, resulting in a stable and durable material.
See Timber cladding for more information. -
Metal profile cladding - Sheets are manufactured in a range of corrugated and other profiles, such as trapezoidal, sinusoidal or half-round. The profiles are manufactured from sheets fed through banks of forming rollers.
Sheets are manufactured in a range of corrugated and other profiles, such as trapezoidal, sinusoidal or half-round. The profiles are manufactured from sheets fed through banks of forming rollers.
See Metal profile cladding for more information. -
Tensile fabric coverings - A fabric membrane is 'stretched' to form a three-dimensional surface that may be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some materials.
A fabric membrane is 'stretched' to form a three-dimensional surface that may be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some materials.
See Fabric structures for more information. -
Brick slips - Brick slips are thin layers of masonry and are of similar appearance to conventional bricks. They are available in a variety of styles and colours.
Brick slips are thin layers of masonry and are of similar appearance to conventional bricks. They are available in a variety of styles and colours.
See Bricks for more information. -
Tile hanging - The traditional method of cladding a property is through the use of tiles. The addition of which can add character to older properties.
The traditional method of cladding a property is through the use of tiles. The addition of which can add character to older properties.
Shakes and shingle - Shakes and shingles are produced from split logs and look similar to timber tiles. Shakes are typically split from the log using a chisel and mallet whilst shingles are sawn off.
Shakes and shingles are produced from split logs and look similar to timber tiles. Shakes are typically split from the log using a chisel and mallet whilst shingles are sawn off.
For more information, see Shingle roofing. -
uPVC - One of the cheaper forms of cladding is uPVC with white being the cheapest option. It can have fewer detailing requirements than timber and requires less maintenance, although it can discolour with age.
One of the cheaper forms of cladding is uPVC with white being the cheapest option. It can have fewer detailing requirements than timber and requires less maintenance, although it can discolour with age.
The term 'prefabrication' describes assemblies that are manufactured under factory conditions and then transported to construction sites for incorporation into building or civil engineering works.
Post-war residential tower blocks and residential building - The acute shortage of housing following the second world war led to a boom in high-rise apartment blocks, and contractors turned to prefabricated panelised wall and floor system building in an attempt to meet demand. However, the jointing systems used and the failure to hide large joints produced a number of monotonous, ugly developments, often with condensation and other problems. Faults were so numerous that the Housing Defects Act 1984 created a scheme to compensate owners who had unwittingly purchased dwellings with defects. It was estimated that 31,000 owners were eligible under the scheme. See Housing Defects Act 1984 for more information.
The acute shortage of housing following the second world war led to a boom in high-rise apartment blocks, and contractors turned to prefabricated panelised wall and floor system building in an attempt to meet demand. However, the jointing systems used and the failure to hide large joints produced a number of monotonous, ugly developments, often with condensation and other problems. Faults were so numerous that the Housing Defects Act 1984 created a scheme to compensate owners who had unwittingly purchased dwellings with defects. It was estimated that 31,000 owners were eligible under the scheme. See Housing Defects Act 1984 for more information.
In 1968, a gas explosion at Ronan Point, (on Butchers Road, Newham, London) resulted in the collapse of an entire corner of a twenty six floor tower block killing four people and badly injuring seventeen residents. A pensioner striking a match to boil water for tea, inadvertently ignited leaking gas from a joint in her newly-installed cooker. The resulting explosion was enough to blow her through the kitchen door and save her life. However, it lifted the ceiling/floor slab and pushed the wall out resulting in a 'house of cards' collapse (a 'progressive collapse').
The collapse resulted in amendment of the building regulations, introducing a robustness clause so that if one element of a building failed, others would be strong enough to take the increased load, allowing occupants to escape. However, The resulting lack in public confidence brought this type of construction to a rapid halt from which it has never completely recovered.
For more information, see Ronan Point. -
However, there are a great many successful factory-produced buildings in Europe and the Far East. Japan has been producing beautifully-detailed houses for three decades providing many options to the customer, who approach purchase in much the same way as ordering a new car from a production line. The Scandinavians also export highly-insulated timber houses with triple glazing and Germany offers carefully-detailed, unashamedly-modern prefabricated houses.
Current use - Repetition
Repetition - The handling, transportation, craneage and erection costs of prefabrication have to be weighed against in-situ alternatives. Economic justification is often dependent on high volume and repetition. This has led to use in applications such as residential blocks, hotels and houses. Architectural success in disguising panel joints has improved public opinion, helping to combat the perception that prefabrication is 'unsightly' or 'cheap'.
The handling, transportation, craneage and erection costs of prefabrication have to be weighed against in-situ alternatives. Economic justification is often dependent on high volume and repetition. This has led to use in applications such as residential blocks, hotels and houses. Architectural success in disguising panel joints has improved public opinion, helping to combat the perception that prefabrication is 'unsightly' or 'cheap'.
Time - Where there is a short programme for construction, and so time has a higher priority than cost, prefabrication can allow parallel working on different aspects of a project.
Where there is a short programme for construction, and so time has a higher priority than cost, prefabrication can allow parallel working on different aspects of a project.
For example: -
The Trustees of Ascot Racecourse were only prepared to lose one year of Royal Ascot racing during which the old grandstand had to be demolished and replaced with a new 50,000 sq m equivalent. As a result, the frame and steppings were manufactured while racing took place under the old facilities. The new structure, consisting of composite concrete and steel, was installed in record time.
Bridges over motorways are often prefabricated to avoid causing traffic congestion.
Avalanche shelters have a narrow timescale between seasons in which construction can take place so are mostly prefabricated structures.
Quality - The quality achievable with factory prefabrication is generally higher than can be achieved on site. This particularly applies to welding and hot trades such as pipe work and mechanical services. Back-to-back toilet and basin units mounted on steel framework are commonplace. Even mini plant rooms lend themselves to prefabrication. This can save a lot of complex site work in confined spaces.
The quality achievable with factory prefabrication is generally higher than can be achieved on site. This particularly applies to welding and hot trades such as pipe work and mechanical services. Back-to-back toilet and basin units mounted on steel framework are commonplace. Even mini plant rooms lend themselves to prefabrication. This can save a lot of complex site work in confined spaces.
Advantages - The advantages of prefabrication include:
The advantages of prefabrication include: -
Programme savings due to the ability to progress work as a parallel operation in a factory and on a construction site.
Factory tolerances and workmanship is of a higher quality and consistency to that achieved on site.
There tends to be less waste. - Independence from adverse weather and winter working.
Independence from adverse weather and winter working. - An alternative means of production where there may be shortages of local skilled labour.
An alternative means of production where there may be shortages of local skilled labour.
Access to cheaper labour markets. For instance two hundred prefabricated timber lodges for short holiday lets in Pembrokeshire were sourced from Eastern Europe.
Greater programme certainty. - The factory environment can allow better safety than the construction site.
The factory environment can allow better safety than the construction site.
Disadvantages - The disadvantages of prefabrication include:
The disadvantages of prefabrication include: -
Road transport maximum widths. - The need for police escorts.
The need for police escorts. - Height restrictions under bridges.
Height restrictions under bridges. - Daytime traffic restrictions in city centres.
Daytime traffic restrictions in city centres. - Maximum load capacities of site craneage and temporary gantries.
Maximum load capacities of site craneage and temporary gantries.
Additional cost of temporary bracing for transportation and/or lifting or permanent framing to support prefabricated assemblies.
Additional cost of pre-assembly in the factory prior to dismantling for transport and delivery.
The insitu work abutting prefabricated assemblies requires a higher degree of accuracy than is normally associated with on-site building work to avoid interface problems.
A mistake in the mass production of prefabricated elements ahead of the measurable site work is a serious risk. Reputedly there is a field in which sixty prefabricated concrete staircases are buried as they had been incorrectly manufactured for a tower block in the City of London.
Sustainability is an issue regarding the transportation of the materials to the construction site.
Factory production requires predictable and consistent demand, whereas construction tends to require large numbers at the same time, then none.
A rainscreen (sometimes referred to as a drained and ventilated or pressure-equalised faade) is part of a double-wall construction that can be used to form the exterior walls of buildings.
Rainscreen cladding systems were first investigated in the 1940s. They were first used in practice in the 1950s and became more commonplace in the 1960s.
The Centre for Window and Cladding Technology (CWCT) defines a rainscreen cladding system as '...a wall comprising an outer skin of panels and an airtight insulated backing wall separated by a ventilated cavity. Some water may penetrate into the cavity but the rainscreen is intended to provide protection from direct rain'.
Typically rainscreens are formed of relatively thin, pre-fabricated panels. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
There are two basic types of rainscreen: -
Drained and ventilated rainscreen cladding systems allow any penetrating moisture to drain or evaporate and vent to the outside. In this case it is necessary to detail the faade so that any penetrating water cannot cross the gap between the rainscreen and the internal wall construction.
Pressure-equalised (PE) rainscreen cladding systems allow the movement of air between the inside and outside of the rainscreen. This equalises the pressure across the rainscreen so that water is not driven, or sucked through the joints.
The difference between the two systems relates to how much water can penetrate the joints, with drained and ventilated systems allowing more water to penetrate. However, the definitions are relatively vague, and the distinction has become somewhat blurred.
Rainscreen cladding can be fabricated from metal sheeting such as aluminium, stainless steel, zinc, copper and so on, or can be a formed from metal composite materials (MCM) which consist of two skins of metal (such as aluminium, or ACM) bonded to either side of a lightweight core such as polyethylene (PE) or polyurethane (PUR), a profiled metal core or a mineral core. Other materials, such as terracotta, brick slips, stone, timber and so on are also used.
Rainscreens are generally cost-effective, lightweight, and easy to install, maintain and replace. Some systems are simply clicked onto supporting rails without the need for additional fixings. They can be used on new-build and refurbishment projects.
Aggregate is the term given to material frequently used in construction as a means of stabilising and reinforcement. Aggregates are widely used in drainage applications and as base material under foundations and roads. In the 10 years ending in 2010, 2.5 billion tonnes of aggregates were consumed by the UK. These aggregates were supplied from various sources:
Land based - The largest source is from quarrying of the land for sand and gravel, or for rock suitable for crushing (mainly limestone, sandstone, and igneous rock, but also some unusually hard occurrences of chalk, ironstone, slate, etc.).
The largest source is from quarrying of the land for sand and gravel, or for rock suitable for crushing (mainly limestone, sandstone, and igneous rock, but also some unusually hard occurrences of chalk, ironstone, slate, etc.).
Marine - Sand and gravel is dredged from the seabed and is a regionally significant source.
Sand and gravel is dredged from the seabed and is a regionally significant source.
Recycled and by-products - A wide variety of construction wastes and industrial by-products make a major contribution to supply. These include construction, demolition and excavation wastes, slags and ashes, and mineral wastes;
A wide variety of construction wastes and industrial by-products make a major contribution to supply. These include construction, demolition and excavation wastes, slags and ashes, and mineral wastes;
Specialist - Small amounts of certain lightweight and high density aggregates are manufactured for specialist purposes.
Small amounts of certain lightweight and high density aggregates are manufactured for specialist purposes.
Imported - The balance of supply consists of imported material (mainly as crushed rock or value-added products) principally from elsewhere in the UK and Norway.
The balance of supply consists of imported material (mainly as crushed rock or value-added products) principally from elsewhere in the UK and Norway.
The industry takes its environmental impact very seriously and as a result the UK industry has become a world leader in terms of the quality of its land restoration work. More than 700 Sites of Special Scientific Interest have their origins in mineral operations. In 2009, the industry planted 313,000 trees and 14.4 km of hedgerows. By 2009, there were 283 liaison groups in aggregate quarries.
As a basic raw material aggregates can be put to many uses, although certain tasks may require a specific type of aggregate. A large proportion of aggregate is used to manufacture concrete, as well as the cement that is used in the concrete.
Aggregates are used in construction to provide drainage, fill voids, protect pipes, and to provide hard surfaces.
Aggregates are not just used for construction. A vast array of other products, many of which are taken for granted, are manufactured using materials derived from quarrying. These include: paper, glass, cosmetics and toothpaste to name but a few. Aggregates are also used in agriculture, food manufacture, and water and sewage purification. Water will percolate through a trench filled with aggregate more quickly than it will through the surrounding soil, thus enabling an area to be drained of surface water. This is frequently used alongside roads in order to disperse water collected from the asphalt surfacing.
Voids created around the foundations of buildings during construction are filled with aggregate because it is easier to compact than the original soil that was removed, resulting in a more solid finish that will support the structure. Aggregates generally are not affected by the weather as much as soils, particularly clay soils, and will not suffer from shrinkage cracking during dry spells.
Pipes laid to convey treated water, or as conduits for cables, need to be protected from sharp objects in the ground and are therefore laid on, and surrounded by, fine aggregate before trenches are backfilled.
Unpaved roads and parking areas are covered in a surface layer of aggregate to provide a more solid surface for vehicles, from bicycles to lorries. This prevents the vehicles from sinking into the soil, particularly during wet weather.
Concrete - Concrete is a mixture of aggregates, cement and water. The purpose of the aggregates within this mixture is to provide a rigid skeletal structure and to reduce the space occupied by the cement paste. Both coarse aggregates (particle sizes of 20 mm to 4 mm) and fine aggregates (particle sizes less than 4 mm) are required but the proportions of different sizes of coarse aggregate will vary depending on the particular mix required for each individual end use.
Concrete is a mixture of aggregates, cement and water. The purpose of the aggregates within this mixture is to provide a rigid skeletal structure and to reduce the space occupied by the cement paste. Both coarse aggregates (particle sizes of 20 mm to 4 mm) and fine aggregates (particle sizes less than 4 mm) are required but the proportions of different sizes of coarse aggregate will vary depending on the particular mix required for each individual end use.
The smaller the aggregate size the greater its surface area and the more cement will be required to bind it all together, resulting in a higher cost. However, in general terms, the greater the quantity of cement used the stronger the concrete will be. Therefore, a balance needs to be made between the strength requirements of the end use and the price willing to be paid.
Asphalt and roadstone - This category includes not just roads, but also pavements, airport runways, school playgrounds, car parks, most footpaths or cycleways, and other similar structures. Although each type of structure will require some variation in the material, it is useful to look at the basic structure of roads because they represent the bulk of the aggregate use in this category.
This category includes not just roads, but also pavements, airport runways, school playgrounds, car parks, most footpaths or cycleways, and other similar structures. Although each type of structure will require some variation in the material, it is useful to look at the basic structure of roads because they represent the bulk of the aggregate use in this category.
The subgrade represents the natural soil, which will be compacted before the road construction starts. The capping layer is an optional layer, used when the local soils require extra strength, and it is not coated with bitumen. The sub-base is the main uncoated roadstone layer and its role is to give strength and act as a solid platform for the layers above.
The binder course (previously two layers known as the base course and roadbase) and surface course (previously known as wearing course) are commonly called 'asphalt' or 'tarmacadam'. They consist of coarse aggregates, with particle sizes typically between 2 mm to 28 mm, and fine aggregates, with particle sizes of less than 2 mm, mixed with a bitumen binder and occasionally some additional filler if required. The exact sizes required for the coarse aggregates will depend on the particular use and the asphalt recipe specified.
Railway ballast - A fully loaded train weighs a considerable amount (> 2 000 tonnes), added to this is the weight of the track itself and the sleepers it rests on. A very tough aggregate is needed to support this weight and distribute the load of a passing train to avoid serious damage to the ground, or other structures, underneath. Similarly the railway track and sleepers must be held in place firmly and not move as a train passes along them.
A fully loaded train weighs a considerable amount (> 2 000 tonnes), added to this is the weight of the track itself and the sleepers it rests on. A very tough aggregate is needed to support this weight and distribute the load of a passing train to avoid serious damage to the ground, or other structures, underneath. Similarly the railway track and sleepers must be held in place firmly and not move as a train passes along them.
Railway ballast generally consists of a tough igneous rock, such as granite, with large (40-50 mm size) angular pieces that lock together. Because of the way igneous rock is formed it is highly resistant to pressure and does not break easily.
Non-aggregate uses of sand, gravel and crushed rock materials
Cement - Cement is a substance manufactured from limestone and shale, with other minor additives, at temperatures in excess of 1,200C. It has unique properties - as a powder it is loose and friable, but mixed with water it hydrates into a paste and then as it dries it sets hard and binds all the surrounding particles together.
Cement is a substance manufactured from limestone and shale, with other minor additives, at temperatures in excess of 1,200C. It has unique properties - as a powder it is loose and friable, but mixed with water it hydrates into a paste and then as it dries it sets hard and binds all the surrounding particles together.
Agriculture - Lime is taken up by plants (either crops or grass) and trees but is also naturally lost from soils through leaching by rainwater and the use of fertilisers. This can result in an increase in acidity, loss of fertility in the soil and sometimes an adverse affect on soil structure.
Lime is taken up by plants (either crops or grass) and trees but is also naturally lost from soils through leaching by rainwater and the use of fertilisers. This can result in an increase in acidity, loss of fertility in the soil and sometimes an adverse affect on soil structure.
To redress the balance, 'agricultural lime' is applied to fields to maintain the necessary growing conditions for crops or grassland. Lime can be simply ground limestone or dolomite (which also contains magnesium) or burnt limestone, (or burnt dolomite) where the rock is heated in a kiln.
Glass - Glass is made from melting silica sand at a high temperature, in the presence of sodium as a flux. The molten glass, at approximately 1,000C is poured continuously from a furnace onto a shallow bath of molten tin, where it spreads out evenly. It is then cooled quickly before crystallisation can occur.
Glass is made from melting silica sand at a high temperature, in the presence of sodium as a flux. The molten glass, at approximately 1,000C is poured continuously from a furnace onto a shallow bath of molten tin, where it spreads out evenly. It is then cooled quickly before crystallisation can occur.
Industrial and other uses - Limestone is used as a flux in the extraction of iron from iron ore. Iron is extracted from ore by heating in a furnace. Limestone is added so that the silicon in the ore forms a calcium silicate (with the calcium carbonate that is limestone) otherwise it would form an iron silicate and thus reduce the quantity of metallic iron produced. The calcium silicate, together with other impurities, forms the 'slag' and this substance can be used as a lightweight secondary aggregate.
Limestone is used as a flux in the extraction of iron from iron ore. Iron is extracted from ore by heating in a furnace. Limestone is added so that the silicon in the ore forms a calcium silicate (with the calcium carbonate that is limestone) otherwise it would form an iron silicate and thus reduce the quantity of metallic iron produced. The calcium silicate, together with other impurities, forms the 'slag' and this substance can be used as a lightweight secondary aggregate.
Sand, usually silica sand, is used to make moulds in a foundry. These are the hollow containers into which molten metal is poured to produce a casting of a particular shape. The exact type of sand used depends on the particular metal or alloy that is to be cast, but it usually contains clay and/or some other material to bind it together.
The burning of coal at power stations produces sulphur dioxide, one of the main gases that causes acid rain. Rather than simply emit this gas along with their other flue gases, most coal fired power stations today use limestone in a process known as 'flue-gas desulphurisation'.
Limestone is finely crushed and mixed with water to form a slurry. It is then sprayed into the absorber tower of the power station where a chemical process converts the limestone and sulphur into gypsum. This 'artificial' gypsum is then recovered and sold for the manufacture of plasterboard.
Limestone, or calcium carbonate, also has many other uses. Ground to a fine powder it is used as a whitening agent or filler in paper, adhesives, paint, plastics, PVC, toothpaste, medical tablets and cleaning products. It is also used to provide additional calcium in vitamin and mineral supplements, flour and animal feed.
Specialist aggregates - Specialist aggregates are required for use in certain demanding applications; notably where lightweight members are required in constructions or where heavy, high density materials are required.
Specialist aggregates are required for use in certain demanding applications; notably where lightweight members are required in constructions or where heavy, high density materials are required.
Light weight aggregate - Light weight aggregates (LWA) are required for situations where concrete is required that imposes low loads on structural elements of constructions. The aggregates therefore need to have low density and weight, achieved by using porous materials, but adequate strength.
Light weight aggregates (LWA) are required for situations where concrete is required that imposes low loads on structural elements of constructions. The aggregates therefore need to have low density and weight, achieved by using porous materials, but adequate strength.
A variety of materials can be pelletised (formed into pellets) and heated causing them to harden and expand. These include clay, shale and slate, sludge (e.g. from sewerage works), fine grained sediments dredged from the sea or rivers, and pulverised fuel ash.
Other materials that can be used are natural volcanic materials that are full of gas cavities including pumice and scoriae ('natural cinders'). The volcanic materials do not occur in the UK but can be imported, particularly from Italy.
High density aggregate - High density aggregates are required for manufacture of concrete that is capable of, for instance, attenuating radiation and thus be suitable for shielding nuclear installations and medical facilities such as radio-therapy treatment rooms.
High density aggregates are required for manufacture of concrete that is capable of, for instance, attenuating radiation and thus be suitable for shielding nuclear installations and medical facilities such as radio-therapy treatment rooms.
Aggregates are a most critical and important component of high density concrete and are principally crushed minerals containing relatively heavy elements, in combination with various additives but can also include scrap steel or certain ceramics.
The relevant minerals include crushed hematite and magnetite (both iron oxides), limonite (iron hydroxide) ilmenite (iron titanium oxide) and barite (barytes - barium sulphate). Other additives can include serpentinite (hydrous calcium magnesium silicate) and borax (sodium borate).
An airbrick is a special type of brick that contains holes to allow the circulation of 'fresh' outside air beneath suspended floors and within cavity walls to prevent moisture building up as a result of cold or damp air sitting in voids or empty spaces.
Airbricks have traditionally been manufactured using clay or cast iron. Some modern airbricks are made from plastic which can be more durable and enable a greater rate of airflow. An alternative to airbricks is the use of cast iron grilles, known as air vents.
In addition to helping prevent damp and rot setting in to timber floorboards, airflow can be required to provide ventilation for solid fuel fires, stoves, gas heaters, and so on.
Airbricks should be located and installed so as to maximise the cross ventilation in the underfloor voids, and should be kept clear of obstructions. A consideration when installing a conservatory is that airbricks on the wall of the house can be blocked by the conservatory structure or by vegetation, earth, and so on. Similar care must be taken when constructing extensions, to ensure that ventilation air paths are not obstructed, or that alternative air paths are provided.
Airbricks can be positioned either above or below the damp proof course (DPC) level, and should ideally be incorporated on all sides of a building, typically at least 75 mm above the ground to prevent water ingress.
A disadvantage of using airbricks is that the small holes can allow pests such as mice, slugs, and wasps to enter a building. A possible solution is to fix wire mesh over the airbricks, or use specially-made airbrick covers, which can prevent entry of pests.
NB Weep holes are openings placed in mortar joints of facing materials at the level of flashing, to permit the escape of moisture, or openings in retaining walls to permit water to escape. For more information see weep holes.
Introduction - Annealing is a much-used process of heat treatment which involves heating a material for a given time then allowing it to cool in a slow, controlled manner. The aim is to increase ductility and strength and to remove internal stresses. It is usually applied to glass and metals.
Annealing is a much-used process of heat treatment which involves heating a material for a given time then allowing it to cool in a slow, controlled manner. The aim is to increase ductility and strength and to remove internal stresses. It is usually applied to glass and metals.
Glass - The annealing of float glass immediately after it has been formed helps dissipate any internal stresses which may have been induced during the manufacturing process. The result is a glass that is harder to break than ordinary glass.
The annealing of float glass immediately after it has been formed helps dissipate any internal stresses which may have been induced during the manufacturing process. The result is a glass that is harder to break than ordinary glass.
Manufacturing smaller glass objects may involve annealing as an incidental process i.e cooling takes place over time during manufacture without a specific annealing process. But with larger or more complex objects, such as long ribbons of float glass, a specific annealing process can be introduced using a temperature-controlled kiln called a lehr. NB There can be safety concerns using annealed glass as it can break into large, jagged shards.
A typical annealing process that may form part of the manufacture of float glass
After the glass has been poured onto the molten tin in ribbons at an initial temperature of around 1,200C, it travels under gravity or by top roller gears propelling it forward.
Having cooled slightly to around 1,100C, the glass enters a lehr oven to be annealed i.e allowed to cool very gradually over a specific time period until it reaches the required temperature. The time required to anneal glass will depend on the glass type and the thickness.
When it finally emerges from the oven, the glass may be further cooled by jets of air after which scanners seek any imperfections which, if found, will result in the glass being discarded or recycled.
If glass is not properly annealed, it may retain thermal stresses which can significantly decrease its strength and make for a less reliable product; it may therefore crack or shatter even under small temperature changes, mechanical shock or stress. It can even suffer sudden failure.
Metal - The annealing of metals such as alloys, stainless steel, copper, silver and brass also involves a heat treatment process that alters their physical characteristics, reducing hardness and increasing ductility and malleability. Therefore, metals can be softened in preparation for further processing such as forming, shaping and stamping.
The annealing of metals such as alloys, stainless steel, copper, silver and brass also involves a heat treatment process that alters their physical characteristics, reducing hardness and increasing ductility and malleability. Therefore, metals can be softened in preparation for further processing such as forming, shaping and stamping.
The annealing process for metals is essentially similar to that for glass: the metal is heated to above the temperature required for recrystallisation in the case of steel, copper, silver and brass this will be until they glow. The temperature is maintained for the required time and then cooled in a slow, controlled process, possibly down to room temperature. As the metal cools, recrystallisation takes place within the matrix until the required temperature is reached. However, further heat treatments may be needed, depending on the degree of malleability and hardness required.
Steel requires slow cooing in air to anneal, but copper, silver and brass can also be cooled by quenching (quench annealing) whereby they are cooled quickly by immersion in water.
An ampere (A), also known as amp, is a unit of electrical current equal to the flow of one coulomb per second. It is named after Andre-Marie Ampere who is widely regarded as the leading pioneer of electrodynamics.
The International System of Units (SI) defines the ampere as the unit that is used to measure electric current; current being a count of the number of electrons flowing through a circuit.
One amp is the amount of current produced by a one volt acting through a resistance of one ohm.
Measuring amperes is important when working with electrical systems as a means of ensuring that the wires are not handling a higher current than they are rated for, and therefore risking faults or failure.
Amperes can be measured using a digital multimeter, but since models differ according to the amount of current they can measure, care should be taken to make sure a device with the correct rating is used.
Amperes force law states that there is an attractive or repulsive force between two parallel wires that carry an electric current.
A (non-biological) membrane is a very thin, sheet-like material, such as cling film, soap film or a piece of cloth. Membranes may be used as structural components of tensile structures. A tensile structure is a structure that is stabilised by tension rather than compression. For example, a piece of fabric pulled in opposite directions in a tent or inflatable structure.
Materials that are commonly used as structural membranes include cotton canvas, PVC coated polyester and PTFE coated glass. They may also be formed by foils, films, reinforced films, inflated cushions and so on. For more information see: Architectural fabrics.
These membranes are typically part of a system which makes use of cables, pylons, anchors and so on which force the membrane to adopt a tensioned anticlastic or synclastic form.
From a structural perspective, membranes are extremely thin relative to their span; this means that there are certain stresses such as those resulting from bending which they cannot appreciably develop. Membranes are therefore mainly affected by tensile stresses, and for this reason can be employed usefully as materials of construction in which they bear mainly tension forces. Analogously, just like the shortest line between two points is a straight line, so the smoothest possible surface connecting points on a boundary is a membrane - as is seen for example in the form of soap films, which adopt minimum surface shapes.
Membrane can support loads in a similar way that cables do: they adopt a curved catenary shape (generally doubly curved in the case of membranes), and in so doing, distribute uniformly the two-dimensional forces across their cross-sectional areas.
Essentially, membrane action involves tensile and shear stresses: these are planar i.e they act along the membrane, never perpendicular to it.
Membranes remain more stable under load when they are pre-tensioned. An example is an umbrella, in which the material is placed under a curving pre-tension by the outward force of the struts emanating from the central pole. This means they distort less when subsequently blown by the wind.
Alluvium is loose soil or sediments (such as clay, silt, sand, gravel and so on) that is eroded and carried in suspension by flood or river water before being deposited. The material of alluvium is may be unconsolidated, i.e. not formed together into solid rock, and can by picked up or eroded and carried away by moving water before being deposited elsewhere when the water flow slows down. Where the loose alluvial material is consolidated into a stone-like material (or lithological unit), this is known as lithification.
The fine-grained fertile soil that is deposited by water that flows over flood plains or river beds is known as alluvial soil.
Some of the characteristics of alluvial soils include:
The soil morphology will vary according to the age of the alluvial deposit and how it was formed.
The textural range of the soil can vary widely from gravel to silty clay.
Drainage can vary from very poor to free.
The texture of the soil can vary both vertically and laterally.
It may contain a large amount of organic matter.
The presence of alluvial deposits may mean that the ground conditions are poor and so can require the construction of a raft foundation, or deep pile foundations. In these conditions, strip or pad foundations would require significant excavation.
A cable is a line made of rope, chain or wire that has different functions according to the application it is used for. It can either tie together two points or simply connect them, as in electricity conveyance or data transmission, and can be loadbearing or non-loadbearing. Cables can be vertical, diagonal, horizontal, or may follow a characterisitc catenary shape that curves with gravity to a low point in the middle of the cable.
Types of cable - Mechanical
Mechanical - Mechanical cables usually transfer a load between two points, so that an action at on one point causes a corresponding mechanical action at the other. For example:
Mechanical cables usually transfer a load between two points, so that an action at on one point causes a corresponding mechanical action at the other. For example:
In an old-fashioned bell-pull, the bell rings when the other end of a cable/wire is pulled (usually at the front door).
The steel cables on a suspension bridge transfer the weight of the road/rail deck and passing traffic to the supporting pylons. The cable usually comprises many strands of steel wire that are intertwined for greater strength. Cables can also support lift cars, cable cars, ski lifts etc.
Transmission - Transmission/power cables convey current (electricity cables) and usually comprise one or more wires (sometimes intertwined) that are sheathed with PVC or other insulating material. Fibre optic cables also fall into this category.
Transmission/power cables convey current (electricity cables) and usually comprise one or more wires (sometimes intertwined) that are sheathed with PVC or other insulating material. Fibre optic cables also fall into this category.
The term apartment refers to a self-contained housing unit that occupies only part of a building, typically, on a single level. It is generally associated with North American real estate, although apartments have been common as far back as the Roman times. The term itself is thought to have originated in the mid-17th century, from the French word appartement derived from the Italian appartamento in turn derived from appartare', meaning to separate.
In North America, apartments are typically leased. Residential blocks in which the residents own their accommodation are generally referred to as condominiums.
The term apartment is sometimes considered to be synonymous with the term flat commonly used in the UK. However, Approved document B, Fire Safety, Volume 1 Dwelling houses, defines a flat specifically as; 'a separate and self-contained premises constructed or adapted for use for residential purposes and forming part of a building from some other part of which it is divided horizontally.' and suggests that this '...includes live/work units, i.e. a flat intended to serve as a workplace for its occupants and for persons who do not live on the premises.
An appliance is a piece of equipment designed to perform a specific task, often used to refer to powered equipment such as a gas appliance or an electrical appliance. It generally associated with performing domestic or kitchen functions, such as a washing machine, boiler, microwave, toaster, kettle and so on. Generally appliances are of standardised sizes and types.
Where an industrial function is being performed, the terms equipment, machinery, plant or tool might be more appropriate. Very broadly, the term tools refers to instruments that are used by hand, equipment refers to a set of tools used for a single purpose and plant refers to heavy machinery. At the smaller scale, there may be some overlap between what is considered to be plant, small plant, tools, small tools, light equipment or equipment.
The term appliance may also refer to a fire engine.
Masonry is generally used to form the walls and other solid elements of buildings and structures such as bridges, tunnels and so on. It may be load bearing, forming an integral part of the structure, or non-load bearing, such as a partition wall or cladding.
Generally the size of the units is suitable for being laid by one person, although, increasingly, masonry is delivered to site in prefabricated panels that are craned into position. Masonry is often formed by laying a number of interlocking units, bound together by mortar, however, dry set masonry relies on the friction between the units to prevent movement, and does not require mortar.
Masonry is very strong in compression, but less effective at resisting lateral loading or tension forces. Additional strength can be achieved by increasing the thickness of the masonry, by the addition of piers or buttresses, or by the incorporation of reinforcement.
Masonry walls may have complex constructions to optimise performance, that may include hollow sections in the masonry itself, a cavity between internal and external leaves of the wall, insulation, a vapour barrier and internal and external finishes and decoration.
However, generally masonry does not require finishing and decorating and is very durable, so is relatively inexpensive to maintain and repair. It tends to offer good thermal mass, high acoustic insulation and good resistance to fire.
Masonry tends to be heavy, and so requires strong foundations. It can be prone to frost damage, staining and disintegration of joints.
In classical architecture, the term arcade refers to a series of arches supported by columns or other vertical elements such as piers. This can be used to form a passageway between arches and a solid wall, or a covered walkway providing access to commercial buildings or markets. Arcades are structurally very strong, and so can carry large loads and stretch for large distances.
Arcades were first developed by the Romans, who took inspiration from ancient aqueduct designs. They used arcades to construct large wall structures; the most famous example being the Colosseum in Rome which has 80 arcaded openings on its first three storeys.
Roman arcades came to be distinguished by the use of pilasters that were attached to piers carrying an entablature. The form developed to become arches resting on the capitals of a row of columns. This style was also adopted during the Gothic period as a decorative element used to divide a churchs nave wall into three horizontal parts.
Arcades have also featured in medieval cloisters, Islamic courtyards, Renaissance commercial streets, Middle Eastern bazaars, Baroque marketplaces, and modern shopping centres.
Introduction - An arch is a curved structural form that carries loads around an opening, transferring them around the profile of the arch to abutments, jambs or piers on either side.
An arch is a curved structural form that carries loads around an opening, transferring them around the profile of the arch to abutments, jambs or piers on either side.
Arches have been a prominent feature in architecture since the time of the Etruscans who are credited with its invention, although the Romans developed it further and spread its use. The techniques involved in designing and constructing arches have since developed into many other structural forms, including vaults, arcades and bridges.
Arches are compressive structures, that is, there are no tensile stresses. They are self-supporting, stabilised by the force of gravity acting on their weight to hold them in compression. This makes them very stable and efficient, capable of larger spans, and supporting greater loads than horizontal beams.
The downward load of an arch must be transferred to its foundations. The outward thrust exerted by an arch at its base must be restrained, either by its own weight or the weight of supporting walls, by buttressing or foundations, or by an opposing tie between the two sides. The outward thrust increases as the height, or rise, of the arch decreases.
Arch construction - Since many building materials, such as masonry and concrete, can resist compression, arches are commonly constructed using these types of material.
Since many building materials, such as masonry and concrete, can resist compression, arches are commonly constructed using these types of material.
The construction of traditional masonry arches is dependent on the arrangement of the bricks, blocks or stones over the opening. Wedge-shaped blocks, called voussoirs, are set flank-to-flank with the upper edge being wider than the lower edge. Downward pressure on the arch has the effect of forcing the voussoirs together instead of apart. The voussoir that is positioned in the centre of the arch is known as the keystone.
This arrangement means that the arch is self-supporting, but temporary supports from below, usually in the form of timber 'centres' (sometimes called 'centreing' or 'arch formers'), must be provided until the keystone has been set in place.
The interior, lower curve of the arch is known as the intrados. The exterior, upper curve of the arch is known as the extrados. The spring, or springing line, is the point from which the arch starts to rise from its vertical supports.
An abutment is structural component typically found at both ends of a bridge, dam, arch or vault to resist and support the lateral and vertical loading of those structures and to transfer those loads to the foundations.
A cathedral is type of church that contains the cathedra (seat) of a bishop. Cathedrals are usually only found in cities.
In architecture, the term pier can be used interchangeably for several different building elements. In general, it is an upright support for a structure or superstructure, but it can also refer to the sections of load-bearing structural walls between openings and different types of column.
Piers are most commonly made of concrete, masonry or treated timber, and installed into prepared holes or shafts.
Piers can serve a similar purpose to piles, but are not installed by hammers and have the potential, if based on a stable substrate, to support a greater load. Pier shafts have been excavated with widths of more than 1.8 m and depths of more than 30 m , capable of supporting high-rise buildings.
Piers can also be used in foundations as a means of raising a structure from the ground, in particular if the structure is on a slope or near a large body of water. They differ from conventional foundations in that they support the structural load at a number of distinct points. This typically requires less excavation and soil disruption than other types of foundation.
The simplest cross-section of a pier is square or rectangular, although other shapes are common. In medieval architecture, drum piers (circular supports), cruciform piers (cross-shaped), and compound piers (combined with pilasters, columns or shafts) were common architectural elements. Compound piers were often used to form an arcade of arches, meeting the ribs descending from the vaults above.
The lower section of a pier may be widened to better distribute the downward pressure of a particularly large superstructure.
Piers used for supporting bridges are often installed in the form of caissons, which are sunk into position to the bearing stratum by excavating from the interior. For more information, see Caisson.
The term 'pier' may also be used to refer to a marine structure that projects into a body of water, supported by a series of columns, typically allowing docking of marine craft, but also used for pleasure. The open structure of piers allows water to flow underneath, in contrast to more solid wharfs or quays.
Clinker in construction - Broadly, clinker refers to a stony residue resulting from burning coal or from a furnace. It is a common component of aggregates, Portland cement, brickwork, blockwork, paving and so on.
Broadly, clinker refers to a stony residue resulting from burning coal or from a furnace. It is a common component of aggregates, Portland cement, brickwork, blockwork, paving and so on.
Archaeological Evidence for Glassworking, Guidelines for Recovering, Analysing and Interpreting Evidence, published by Historic England in 2018, describes clinker as: A fused material produced at high temperatures, here used to describe the waste from coal-fired glass furnaces.
The term clinker built refers to a method of boat building in which the planks that make up the hull overlap. This is also referred to as lapstrake.
Its originates from the word 'clink' or 'clench', ie clenching together, or fusing.
Pavements are a form of exterior surface covering, typically raised and used by pedestrians, running parallel to, and on either side of a road. They provide an area that is separated from, and so protected from vehicular traffic. However, the term can also be used to refer to other paved areas, such as pedestrianised streets, patios, courtyards, driveways, and so on.
Pavements can be constructed using asphalt, concrete, flagstone, cobblestone, artificial stone, bricks, tiles and timber.
The term paver or paviour (pavior in the USA) refers to a paving stone, tile, brick or piece of concrete used to form a pavement surface. They are usually laid to a fall of 1:60 or more to drain water to one or both sides. They are usually built to a minimum width of 1.2 m where this is possible.
Portland cement is used to make almost all concrete. It is also the principal cement used in most masonry mortars and renders. The most commonly used type of Portland cement is Ordinary Portland Cement (OPC), but there are other varieties available, such as white Portland cement.
Cement is a substance used for binding and hardening other materials. Water and cement set and harden through a chemical reaction known as 'hydration'. The process of hardening is described as 'curing', and it requires particular conditions of temperature and humidity.
Mixed with water, sand and rock, portland cement forms concrete.
The Leeds-based bricklayer Joseph Aspdin was the first person to make Portland cement in the early-19th century, by burning powdered limestone and clay in a kitchen stove.
The 'dry' method is the most common way of manufacturing Portland cement. The process begins with the quarrying of the principal raw materials limestone, clay, chalk or marl, which may be combined with shale, blast furnace slag, silica sand, iron ore, and so on.
The quarried material is then crushed, first to reduce it to a maximum size of approximately 6 inches, and then to about 3 inches or less using secondary crushers or hammer mills. The crushed rock is then ground, mixed and fed into large rotary kilns, which heat it to approximately 2,700F (1,500 Celsius). Coolers are used to bring down the temperature of the clinker, before cement plants grind and mix it together with small amounts of gypsum and limestone. Once this is done, it can be packaged and sold for use in construction.
An alternative, though less common manufacturing technique is the wet method. It is similar to the dry method except that before being fed into the kiln the raw materials are ground with water.
As the production of Portland cement involves quarrying and the use of large amounts of energy to power the kilns, it is not considered to be a 'sustainable' material.
Asphalt is a mixture of asphalt cement and aggregates, hot-mixed in an asphalt plant and then laid hot to form the surface course of a flexible pavement. Asphalt paving provides a stable, safe and durable road surface.
Asphalt is specifically designed to carry the loads without any shear. It is also flexible as it distributes any imposed load by deflecting it slightly without cracking or deforming. It is skid-resistant and allows quick drainage of water from its surface. It is durable and becomes more dense over time, with the use of traffic.
The asphalt binder film thickness around each aggregate particle accounts for a large part of the asphalt's durability.
If the thickness of the film surrounding the aggregate particles is inadequate, it is possible that the aggregate may become accessible to moisture through holes in the film. Should it be hydrophilic, water will displace the asphalt film, and the cohesion will be gone. This process is typically referred to as stripping. The optimum asphalt binder content is determined by mix design which should provide adequate film thickness.
Introduction - The term skyscraper refers to tall, continuously habitable buildings of 40 floors or more. Throughout the history of the built environment, skyscrapers have been developed as prestigious structures demonstrating the power and wealth of a city or nation and producing a sense of wonder.
The term skyscraper refers to tall, continuously habitable buildings of 40 floors or more. Throughout the history of the built environment, skyscrapers have been developed as prestigious structures demonstrating the power and wealth of a city or nation and producing a sense of wonder.
Although the term skyscraper was only coined in the late-19th century to describe buildings of steel-framed construction of at least 10 storeys the desire for tall and impressive buildings extends back to the Pyramids of Giza in Egypt and the cathedrals built across Europe. The tall structures built throughout the Middle Ages were intended to fulfill the religious function of acquiring a better connection with the gods, or the military function of enabling a good vantage point.
The development of more modern construction techniques began with the arrival of the Industrial Revolution. Two specific innovations in the 19th century made skyscrapers much more practical:
In 1857, lifts or elevators meant that building height was no longer such a concern to occupants in terms of safe passage between floors.
The introduction of iron frame and glass curtain wall construction instead of stone or brickwork meant that buildings could be designed to be much taller than before.
Skyscrapers are also a feature of urbanisation. From the 19th century onwards, cities started becoming denser, creating the necessity for building upwards to maximise floor space efficiency. Today, skyscraper construction is still largely dictated by economics, with the price and availability of urban centre land justifying building upward.
Early skyscrapers - Although only 5 storeys tall, the Oriel Chambers in Liverpool, built in 1864, was the first building in the world to use an iron frame and glass curtain wall construction which enabled greater load-bearing capabilities.
Although only 5 storeys tall, the Oriel Chambers in Liverpool, built in 1864, was the first building in the world to use an iron frame and glass curtain wall construction which enabled greater load-bearing capabilities.
In 1885, the Home Insurance Building in Chicago was completed and is widely recognised as the first skyscraper, despite being only 10 storeys (42 m) tall.
In 1889, Chicagos Rand McNally Building became the first all-steel framed skyscraper.
In 1891, St Louis Wainwright Building became the first steel-framed building with soaring vertical bands to emphasise the buildings height.
In 1895, New Yorks American Surety Building secured the title of worlds tallest skyscraper (21 storeys).
While height restrictions were implemented across Europe in the early-20th century, New York and Chicago led the way in skyscraper construction.
In 1902, the Flatiron Building (20 storeys) was built, and is now one of the most iconic examples of the New York skyscraper boom. This boom saw the completion of the Metropolitan Life Insurance Tower (50 storeys), the Woolworth Building (60 storeys), the Bank of Manhattan (71 storeys) and the Chrysler Building (which, upon completion in 1930, was briefly the worlds tallest building at 77 storeys).
In 1931, New Yorks Empire State Building was completed. At 102 storeys (381 m) tall, it stood as the worlds tallest building for the next 40 years.
Modern skyscrapers - As buildings became ever taller, the techniques and methods of construction changed. Steel beam grids and columns were utilised. Concrete steel and glass were used for their strength, durability, and resistance to the weather. To try and alleviate the risk of wind sway, engineers began installing diagonally-braced steel trusses to ensure a stronger core.
As buildings became ever taller, the techniques and methods of construction changed. Steel beam grids and columns were utilised. Concrete steel and glass were used for their strength, durability, and resistance to the weather. To try and alleviate the risk of wind sway, engineers began installing diagonally-braced steel trusses to ensure a stronger core.
Throughout the 1960s, the structural engineer Fazlur Khan developed a new method of skyscraper construction. He moved most beams and columns to the outside walls, and in so doing creating a stiff tube that offered greater structural stability.
In 1972, the World Trade Center (415 m) became the worlds tallest building and was an early adopter of Khans construction methods.
In 1973, Chicagos Willis (or Sears) Tower (100 storeys, 442 m) was completed.
Over the next decades, the skyscraper boom spread into Asia, South America and Europe, culminating in Malaysias Petronas Towers becoming the tallest skyscraper in 1998 (452 m), followed by Taiwans Taipei 101 in 2004 (509 m).
Since 2010, the tallest building in the world has been Dubais Burj Khalifa (828 m)
Mortar is one of the oldest building materials, enabling large structures to be constructed from small, easy-to-handle components.
It is composed from a mixture of a fine aggregate (typically sand), a binder (typically cement, but sometimes lime or a combination of lime and cement) and water. This combination creates a paste that is used in masonry construction as a bedding and adhesive to bind and fill the gaps between adjacent blocks of brick, concrete or stone.
Mortar is applied as a thick paste which sets hard as it cures. It creates a tight seal between bricks and blocks to prevent air and moisture entering into the construction. It can compensate for variations in brick or block size to produce an aesthetically-pleasing and structurally-sound construction. Generally, it is structurally weaker than the blocks or bricks it bonds, creating a sacrificial layer that is more easily repaired than defects would be in the bricks or blocks themselves.
Mortar is generally very durable and has a typical lifespan of between 20-30 years, after which repairs (or repointing) can be necessary to fill cracks or gaps that may begin to appear.
Mortar may be provided in its component parts and mixed on site, or factory-mixed. The two main types of factory-produced mortar are:
Wet ready-to-use mortar that requires no further mixing.
Dry ready-to-use mortar which requires the addition of water.
Factory-produced mortar is made under tightly-controlled conditions and provides:
Consistent quality, colour and strength. - Reduced mixing and labour costs.
Reduced mixing and labour costs. - Reduced wastage.
Reduced wastage. - Guaranteed specification.
Guaranteed specification. - Improved site health and safety.
Improved site health and safety. - For the different types of mortar, see Types of mortar.
For the different types of mortar, see Types of mortar.
The profile of mortar joints (pointing) can be varied depending on exposure or to create a specific visual effect. The most common profiles are; flush (rag joint), bucket handle, weather struck, weather struck and cut, and recessed.
A wide range of colours are available to match or contrast with the surrounding bricks or blocks, or to match existing mortar. Pigments are specified according to BS EN 12878:2014 Pigments for the colouring of building materials based on cement and/or lime. Specifications and methods of test.
A range of admixtures can be included in mortar, such as plasticisers, bonding agents, and waterproofing. These can be specified according to BS EN 934-3:2009+A1:2012 Admixtures for concrete, mortar and grout. Admixtures for masonry mortar. Definitions, requirements, conformity and marking and labelling.
Mortar must have good workability to ensure there are no air pockets which might prevent proper bonding. Plasticisers can improve workability by entraining very small air bubbles in the mix. Alternatively, the addition of lime can improve the workability of mortar.
Where porous bricks or blocks are being laid, the mortar may dry quickly, preventing proper levelling and so preventing a good bond from being formed. This can be countered by laying shorter lengths or by limited wetting.
The word spall refers to the breaking of a material into pieces, particularly cracks below the surface that cause part of the surface to come off.
In construction spalling refers to the flaking, cracking, peeling, crumbling or chipping of concrete or brickwork, particularly where parts of the surface might be said to have blown off. This can occur as a result of water penetration, heating (such as during a fire) or by mechanical processes. Spalling is typically caused by poor installation, poor maintenance, poor repairs, or by environmental factors.
Spalling can be inconsequential, that is, a purely aesthetic issue, or it can lead to serious structural damage requiring costly remediation work.
Concrete spalling - A common cause of spalling in concrete is the presence of moisture. This is a particular problem in basements, where moisture, often combined with salt, pushes out from within concrete. Striated lines, discolouring and coarse texture are physical signs of spalling.
A common cause of spalling in concrete is the presence of moisture. This is a particular problem in basements, where moisture, often combined with salt, pushes out from within concrete. Striated lines, discolouring and coarse texture are physical signs of spalling.
Heat and mechanical pressure can result in uneven expansion of concrete and subsequent fracture. Particularly concrete that includes reinforcing bars, which absorb heat at a different rate and may expand or corrode. Applied heat may also release the water contained within the concrete.
Whether or not concrete will spall varies greatly and is dependent upon a number of factors, such as:
The configuration of materials. - Composition of the material.
Composition of the material. - Temperature and temperature change.
Temperature and temperature change. - Local conditions.
Local conditions. - Length of time since curing (water content is higher in concrete that has recently been poured).
Length of time since curing (water content is higher in concrete that has recently been poured).
Ability of the surface to absorb liquid. - Expansion and contraction of the freeze/thaw cycle.
Expansion and contraction of the freeze/thaw cycle.
Presence of chemicals such as de-icers and fertilizers.
Steps can be taken to prevent spalling when the concrete is first poured, as the mix of concrete will influence the likelihood of spalling in the future. Proper air entrainment should be assured, typically a minimum of 4% air in mixture, allowing for enough airspace within the concrete to accommodate water expansion.
The appropriate mix of sand, cement and aggregate should be achieved, as insufficient aggregate may result in a top layer that is weak and prone to spalling. The mix should be kept as dry as possible, as high water content can compromise the concretes strength, with the correct curing time allowed.
Action should be taken quickly if spalling is detected in concrete installations, as the risk of damage rises the longer remediation is delayed.
Brickwork spalling - Bricks will deteriorate through spalling as a result of moisture penetration, eventually resulting in the brick cracking. This can be a particular problem with softer, more absorbent bricks.
Bricks will deteriorate through spalling as a result of moisture penetration, eventually resulting in the brick cracking. This can be a particular problem with softer, more absorbent bricks.
One of the most common causes of spalling in old, solid walled buildings is the use of cement pointing, over soft lime mortar joints. Interstitial moisture is lost primarily through the mortar joints - the lungs of the wall - and when blocked with cement, this moisture then tries to escape through the brick faces, blowing them.
Water is absorbed by the porous surface of bricks, and in cold periods, expansion by freezing can cause bricks to crack. Fluctuations in weather, humidity and temperature are a major factor, as even the slightest movement in the structure can leave holes in mortar through which moisture can penetrate to the brickwork. Very soft lime mortar will alleviate this problem, being highly porous, and it soaks up moisture, releasing it as conditions change. Other elements of the building can lead to similar problems, for instance, windows and gutters that leak, damaged chimneys, doors and windows and around the foundations.
Masonry sealants should never be used. They trap moisture and salts and exacerbate spalling. Alternatively, drainage installation around the building can help prevent water pooling near the foundation level, and repairing leaks and other defects can remove sources of dampness. Water splash from badly fitted gutters is a common cause.
If spalling has already occurred, damaged bricks can be replaced, but the cause of the moisture should also be identified and dealt with appropriately.
Crystallisation of salts just below the surface of bricks can also cause spalling. This is known as cryptoflorescence. The problem is often associated with magnesium salts. Cryptoflorescence is associated with a large build-up of salts and usually occurs where old, relatively weak, bricks are re-used inappropriately, particularly in areas of excessive dampness. It can also occur if the brickwork has been covered by a surface treatment because the salts may crystallise behind the treated surface and force it off.
A parapet is typically the uppermost reaches of a wall that extends above the roof level and provides a degree of protection to roof, gutters, balconies and walkways of houses, churches, castles, apartment blocks, commercial and other buildings. It may be constructed from brick, stone, concrete, timber or even glass. A parapet may also prevent fire spreading to a roof and provide a degree of protection from a sudden and potentially fatal fall.
On a pitched roof, a parapet may only exist where a wall rises above the eaves, which is generally the lowest point of the roof as it terminates above a gutter; this point forms a convenient valley into which a gutter can be placed.
The top of a parapet will usually be terminated by some form of capping or coping in brick, stone, or concrete, or even sheet metal, such as lead, zinc or steel.
Cappings are usually flush with the sides of the wall while copings extend from the face. Tradiitonally, copings would extend by around 50mm or more on either side of the wall to provide weather protection to the area below; they would also be throated (ie incorporate a continuous semi-circular recess called a 'drip') to convey water away from the wall to reduce the risk of damp penetration.
Problems with brick parapets - Two of the most common problems encounteerd with brick parapets are bowing, where the parapet develops an unsightly lean to one side, usually the roof side; and cracking of the brickwork. If either of these becomes excessive, rebuilding the parapet may be necessary.
Two of the most common problems encounteerd with brick parapets are bowing, where the parapet develops an unsightly lean to one side, usually the roof side; and cracking of the brickwork. If either of these becomes excessive, rebuilding the parapet may be necessary.
The reasons for such problems can be complex but they usually involve:
One side of the parapet getting more sunshine (heat) and rain (and therefore more saturation) than the other side. This may cause a degree of differential movement which will be exacerbated as, unlike the brickwork at the lower reaches which is constrained by the weight of the brickwork above, the brickwork in a parapet has far less constraint and therefore can move more freely. Differential weathering mechanisms will be heightened when one side of the parapet faces north and the other faces south.
Cracking of the brickwork in a parapet may be the result of insufficient movement joint provision to absorb any expansion. Movement joints in parapets (and freestanding walls) should be more generous than those in a structure's walls because the lack of restraint in the parapet can amplify the effects of movement.
A herm (or herma) is a rectangular pillar topped with a head or bust. It is believed these structures were used in Ancient Greece to mark boundaries and were often inscribed with distances.
The word herm may be representative of the Greek phrase for blocks of stone, but it may also be linked to the Greek god, Hermes. Associated with roads and borders, Hermes was a phallic god connected to the concepts of luck and fertility. Consequently, hermae frequently included carvings of genitals at the suitable height in the otherwise plain base. This symbol was apparently meant to ward off evil.
The herm was later adopted by the Romans who used it as a boundary marker. It was also a method of indicating boundaries in Renaissance and post-Renaissance times.
Herms (or hermae) sometimes took on purely decorative functions and served as sculpture-topped pedestals, either as single units or as pillars supporting figures. This application of the herm may be linked to structural supports such as the telamon (the Roman term) or atlas (also known as atlant, or atlante or atlantid), which were architectural components (such as columns, piers or pilasters) sculpted in a human form.
Plaster is a building material used for coating, protecting and decorating internal walls and ceilings. It can also be used to create architectural mouldings such as ceiling roses, cornices, corbels, and so on.
The most common types of plaster are a composition of gypsum, lime or cement with water and sand. The plaster is typically manufactured as a dry powder and then worked to form a stiff paste by mixing in water before application.
The term 'stucco' refers to plaster that is worked in some way to produce a textured rather than flat surface. See Stucco for more information.
Render is similar to plaster, but is applied to the outside of buildings and has waterproofing properties. See Rendering for more information.
A form of plastering was used by primitive civilisations, creating durable and weather-resistant structures using mud. The Egyptian pyramids contain plasterwork comparable to that used today that remains hard and durable some 4,000 years later.
Greek artisans used plaster, mainly to cover the exterior of temples but sometimes also interiors. Through history, plaster ceilings became increasingly ornamental, with those during the Tudor period being particularly extravagant.
However, the use of plaster as a means of demonstrating artistic skill and expression had waned by the 19th century, when imitation and mechanical reproduction displaced it as a creative medium. However, plaster is still very commonly used as a surface finish for interior walls, ceilings, and still sometimes for exterior walls.
There are a number of different types of plaster, depending on the binder that is used.
Gypsum plaster - Gypsum plaster, or plaster of Paris (POP), is the most common form of plaster for interior walls. It is produced by heating gypsum to around 150C (300 F). When mixed with water, the dry plaster powder re-forms into gypsum. Unmodified plaster starts to set about 10 minutes after mixing, but it will not be fully set until 72 hours have elapsed. Gypsum plaster has good fire-resistant qualities.
Gypsum plaster, or plaster of Paris (POP), is the most common form of plaster for interior walls. It is produced by heating gypsum to around 150C (300 F). When mixed with water, the dry plaster powder re-forms into gypsum. Unmodified plaster starts to set about 10 minutes after mixing, but it will not be fully set until 72 hours have elapsed. Gypsum plaster has good fire-resistant qualities.
Lime plaster - Lime plaster is a composite of calcium hydroxide (lime) and sand (or other inert fillers). It may sometimes be strengthened with animal hair to preventing cracking and reduce shrinkage. The plaster sets through contact with carbon dioxide in the atmosphere which transforms the calcium hydroxide into calcium carbonate (limestone). It is typically more flexible and breathable than gypsum and cement plasters, and is most commonly used on older properties.
Lime plaster is a composite of calcium hydroxide (lime) and sand (or other inert fillers). It may sometimes be strengthened with animal hair to preventing cracking and reduce shrinkage. The plaster sets through contact with carbon dioxide in the atmosphere which transforms the calcium hydroxide into calcium carbonate (limestone). It is typically more flexible and breathable than gypsum and cement plasters, and is most commonly used on older properties.
Cement plaster - Cement plaster is a mixture of sand, cement and water. It is normally applied to masonry interiors and exteriors. While it is capable of achieving a smooth surface, interiors will sometimes require an additional finishing layer of gypsum plaster. Cement plaster offers greater moisture resistance than gypsum plaster.
Cement plaster is a mixture of sand, cement and water. It is normally applied to masonry interiors and exteriors. While it is capable of achieving a smooth surface, interiors will sometimes require an additional finishing layer of gypsum plaster. Cement plaster offers greater moisture resistance than gypsum plaster.
Clay plaster - Clay plaster is considered to be a more sustainable alternative to modern plasters, with a lower embodied energy than gypsum, cement or lime based plasters. It is available with fibre additives to increase its strength, and in a range of natural colours. It is breathable and does not need to be painted.
Clay plaster is considered to be a more sustainable alternative to modern plasters, with a lower embodied energy than gypsum, cement or lime based plasters. It is available with fibre additives to increase its strength, and in a range of natural colours. It is breathable and does not need to be painted.
Plaster is typically built up in layers, with the number of layers depending on the roughness of the surface being plastered. Rough, bare walls could require three coats of plaster, while plasterboard might just require a finishing skim of 2 to 3mm.
The plaster compound, which is typically supplied dry, must first be mixed with water, with care being taken to achieve the correct creamy consistency. Mixing is best achieved by adding the plaster to the water, not the other way round.
The plaster can then be applied to the wall. The first coat is applied, scratched and left to dry. This is followed by the second coat and finally a third finishing layer.
Plastering is a labour intensive and time-consuming process and as a result it has gone into something of a decline in recent years, with techniques such as dry lining gaining in popularity.
While plaster is durable, it can be prone to cracking if the building experiences settlement or if it has been applied incorrectly.
Gypsum is a soft sulfate mineral with the chemical formula CaSO42H2O, also known as calcium sulfate dihydrate. It is comprised of calcium, sulphur bound to oxygen, and water. It is an abundant mineral in sedimentary rocks that has been mined and used for construction and and as a fertilizer since the time of Ancient Egypt.
Pure gypsum is typically white, although impurities create a wide range of different colours. Gypsum is moderately water soluble but exhibits retrograde solubility, meaning it becomes less soluble at higher temperatures. It is fire resistant and is effective at preventing the passage of sound.
In terms of production, gypsum rock is mined or quarried and then crushed and ground into a fine powder. A process of calcining heats the powder, driving off most of the chemically-combined water.
Coal ash is a material produced during the combustion process at coal-fired power stations. It can be used in a range of construction products with little need for further refinement, such as fillers, cement, grouts, blocks, and so on.
In the UK, the types of available coal ash are as follows:
Pulverised fuel ash (PFA). - Furnace bottom ash (FBA).
Furnace bottom ash (FBA). - Cenospheres.
Cenospheres. - Different coal ash-based products will have varying moisture content, degree of compaction, shear strength, and so on. They are categorised according to a number of industry standards setting out the levels of coal ash contained in particular products and what they can safely be applied to. For example, BS EN450-1 provides the specifications and categories for PFA use in concrete and BS EN450-2 defines quality control and statistical compliance.
Different coal ash-based products will have varying moisture content, degree of compaction, shear strength, and so on. They are categorised according to a number of industry standards setting out the levels of coal ash contained in particular products and what they can safely be applied to. For example, BS EN450-1 provides the specifications and categories for PFA use in concrete and BS EN450-2 defines quality control and statistical compliance.
Pulverised fuel ash - Pulverised fuel ash (PFA), also known as fly ash, is a very fine ash that results from burning pulverised coal in coal-fired power stations. The term pulverised comes from the fact that the coal used is a fine powder which can burn efficiently and quickly at a temperature of between 1,250-1,600C.
Pulverised fuel ash (PFA), also known as fly ash, is a very fine ash that results from burning pulverised coal in coal-fired power stations. The term pulverised comes from the fact that the coal used is a fine powder which can burn efficiently and quickly at a temperature of between 1,250-1,600C.
PFA is removed from the flue gas given off from burning coal by electrostatic precipitators. It is collected in silos where it is either sold dry for use in concrete, or moistened for use in fills, grouts, and so on.
Alternatively, some power stations mix the ash with large amounts of water and pump the resulting slurry to lagoons. This lagoon ash is left to drain and then sold for fill and grouting applications.
The chemical composition of PFA differs from Portland cements, in that it wont hydrate with water directly but requires lime and water. PFA is used in combination with Portland cement. Depending on the application, the ratio is typically in the range of 80-60% Portland cement to 20-40% PFA. These mixes often have slower hydration times to similar Portland cement-only mixes, but they may be more durable.
High volume fly ash concrete (HVFA) replaces Portland cement with up to 70% PFA, which reduces the environmental impact of concrete manufacturing.
PFA can also be used in concrete as an inert filler aggregate, or lightweight filler aggregate.
A drainage blanket or capillary break, 300-450 mm, should be placed beneath PFA-based fill materials to prevent the filler from leaching ground water as fine-grained materials have a propensity to do via capillary suction. This can depend on the thickness of the filler layer, and usually if a PFA-based filler layer is greater than 2 m, a stable fill is achieved and there is no need for the precaution of a blanket or break.
There are some environmental benefits to using PFA as a building material. PFA usually replaces virgin aggregates in fill material, thereby reducing the resource-intensive process of extracting and processing such aggregates. Its cementitious properties also reduce the quantity of Portland cement required to create concrete.
In concrete, the low solubility of the PFA sulfate (gypsum) does not cause problems such as excessive retardation or expansion. However, when used as a fill material it has the potential to cause sulfate attack on some metals, such as mild steel. As such, the Specification for Highways states that PFA should not be placed within 500 mm of metallic elements, such as directly over culverts.
Furnace bottom ash - Furnace bottom ash (FBA) is formed from the molten material that falls to the bottom of the furnace during the combustion process at coal-fired power stations. The granular product is extracted, graded and sold as lightweight aggregate for use in concrete blocks.
Furnace bottom ash (FBA) is formed from the molten material that falls to the bottom of the furnace during the combustion process at coal-fired power stations. The granular product is extracted, graded and sold as lightweight aggregate for use in concrete blocks.
Cenospheres - Cenospheres are a coal ash by-product; fine, rigid hollow spheres that are often filled with air or inert gas. They are recovered from ash ponds or lagoons that are often situated at the same site as a coal-fired power station. These can be use as low-density fillers and in the production of lightweight concrete.
Cenospheres are a coal ash by-product; fine, rigid hollow spheres that are often filled with air or inert gas. They are recovered from ash ponds or lagoons that are often situated at the same site as a coal-fired power station. These can be use as low-density fillers and in the production of lightweight concrete.
Pebbledash is a form of render used for the external walls of a building in which the top coat is textured by pebbles and stone fragments to create a rough finish. The wall surface is plastered with render and the pebbledash material thrown and pressed in while still wet.
This is similar to roughcast rendering in which larger stones are applied mixed into the mortar before being applied to walls. This produces a softer finished texture which is often painted. This technique is commonly used for coastal buildings to provide weather protection, and can also be found on medieval buildings and stately homes.
Pebbledash became a popular rendering technique between the 1890s and the 1930s as part of the Arts and crafts movement which sought to revive traditional building processes as forms of vernacular architecture. It was cost-effective but also very durable. These characteristics lead to pebbledash being used widely in the post-war years of housing development, often as means of covering up poor workmanship.
Pebbledash has since come to be a divisive material, often being criticised for being ugly and impervious, as well as for failing to take account of the individual historic fabric of buildings. It is even thought to have a negative impact on the value of a property.
Repointing is a construction technique used in the maintenance of masonry structures.The pointing is the external, i.e. visible, edge of mortar joints between masonry units which are typically 10 mm-wide.
When masonry structures are first constructed, mortar is applied as a thick paste which sets hard as it cures, creating a tight seal between bricks and blocks to prevent air and moisture entering into the construction. It can compensate for variations in brick or bock size to produce an aesthetically-pleasing and structurally-sound construction. However, generally, mortar is structurally weaker than the blocks or bricks it bonds, creating a sacrificial layer that is more easily repaired than defects would be in the bricks or blocks themselves.
As a result, mortar joints can decay over time, due to weathering, frost damage, and so on. When this happens, repointing is undertaken to renew them.
Pointing on older buildings was often made of lime mortar which, compared to harder cement pointing typically used today, may feel soft or powdery, but this does not mean that it needs to be repointed. Only where joints are badly eroded such that voids have formed which are at risk of rainwater and ice making them progressively worse, will they need repointing. In this case it is important that a similar mortar is used, to prevent erosion of the masonry itself (see the image at the top of the page and see: Lime mortar for more information).
Masonry structures in exposed locations tend to be at more risk of weathering than in other locations. Due to variances in exposure, it may only be small patches of masonry that require repointing as opposed to the whole structure. Regardless of the extent of the repointing, it is important that it should resemble the original (both in type, texture, surface profile and colour) as closely as possible, as otherwise the newer pointing can clash with the old.
The process of repointing begins with preparation of the masonry by raking out the defective mortar to a depth of at least 20 mm. The joint should then be dampened with a fine water spray before fresh mortar is applied to the back of the joint using a pointing tool. The type of mortar to be used should be slightly weaker than that of the surrounding masonry; usually (but not always) a 4:1 sand/cement mix. For softer masonry (such as some sandstones), a 'weaker' lime mortar can be used.
Harl, also known as harling (or lime harling), is a technique for weatherproofing the exterior of masonry buildings, traditional to Scotland and Northern Ireland. It is commonly found on Scottish castles as well as more common building types, and was favoured due to its practicality and suitability for the harsh, wet climate.
The term harling derives from the action of hurling wet mortar at a solid wall. This is known as a cast-on finish, as opposed to a floated base coat (traditional to England), or rough-cast work such as pebbledash. In Ireland, it is commonly known as wet dash.
Harling consists of a slaked lime and coarse aggregate mortar which is thrown onto a stone wall, using a slurry of small pebbles or fine stone chips. By embedding a pigment in this material, the need for repainting can be avoided. A specially-shaped trowel is used to throw and then press the material into the surface. Cast-on coatings tend to provide better resistance to weather as the mortar is better compacted and more uniform throughout its thickness compared to trowelled-on coatings.
As the harl is mostly lime render it cures chemically rather than by drying, to provide a weather-protective and decorative coating. Once the harl is set it can be lime washed in various colours.
Ashlar is a type of masonry which is finely cut and/or worked, and is characterised by its smooth, even faces and square edges. It can also be used to refer to an individual stone that has been finely cut and worked until squared.
Ashlar has been used in construction as an alternative to brick or other materials dating back to classical architecture, where it was often used to contrast with rustication (masonry with a purposefully rough or patterned surface).
Courses of ashlar can be horizontal, with blocks laid in parallel, or may be random with deliberately discontinuous vertical and horizontal joints.
Since ashlar blocks are precisely cut on all faces which are adjacent to other masonry, very thin joints can be achieved. The face of the block away from joints may be left rough and unpolished (known as quarry-faced), or may be polished or rendered decoratively. Masons drag is a form of decoration used on softer stone ashlar which involves small grooves applied by a metal comb-like device.
Mortar, or another joining material, is used to bind ashlar blocks together. Other methods of assembly such as metal ties can be used, in a process known as dry ashlar. Such a technique can be seen in the Inca architecture of Cusco and Machu Picchu.
In the UK, ashlar walling can be found in many historic buildings; one notable example being the Royal Crescent in Bath. It is also becoming more popular as a form of exterior cladding in urban commercial developments.
Bentonite is a naturally-occurring material created by the alteration of volcanic ash in marine environments. It consists mainly of the clay mineral smectite, usually montmorillonite, which occur as layers which are compressed between other rock types.
Bentonite is usually obtained by quarrying, with a solid extracted form with a typical moisture content of around 30%. This moisture content is reduced to approximately 15% by air and/or forced drying after being crushed. Once this has been done, bentonite is either sieved in a granular form, or milled into powder form.
In civil engineering, bentonite is used as a thixotropic, support and lubricant agent. Typical applications for this agent include the construction of diaphragm walls, foundations, pipe jacking, tunnelling, and so on. Its viscosity and plasticity also make it suitable for use in Portland cement and mortars.
Bentonites thixotropic properties mean it forms a highly water-resistant gel which, when mixed with additives, can create a permanent barrier to water flow. This is commonly used in situations where soil particles are too small for cement grouting to be suitable, typically to combat seepage in alluvial soils beneath the foundations of dams or other water-bound structures.
For drilling purposes, bentonite can be used as a mud constituent, to seal borehole walls, remove drill cuttings, and so on.
It can also be used in varnishes and paints to act as a thickening and/or suspension agent.
A diaphragm wall is a structural concrete wall constructed in a deep trench excavation, either cast in situ or using precast concrete components. Diaphragms walls are often used on congested sites, close to existing structures, where there is restricted headroom, or where the excavation is of a depth that would otherwise require the removal of much greater volumes of soil to provide stable battered slopes.
Diaphragm walls are suitable for most subsoils and their installation generates only a small amount of vibration and noise, which increases their suitability for works carried out close to existing structures. In addition, floor slab connections and recessed formwork can be incorporated into the walls.
The walls generally range in thickness from 500 - 1,500 mm and can be excavated to depths of over 50 m. Excavation is typically carried out using rope-suspended mechanical or hydraulically-operated grabs. Specific ground conditions or greater depths may require the use of hydromills hydraulically-operated reverse circulation trench cutters to penetrate into hard rock by cutting rather than digging. Hydromills can achieve depths of up to 80 m.
The excavation stability is maintained by the use of a drilling fluid, usually a bentonite slurry. This is a controlled mixture that has thixotropic properties, meaning that it exerts a pressure in excess of the earth and hydrostatic pressures on the sides of the excavation. The walls are constructed, using reinforced or unreinforced concrete, in discrete panel lengths generally ranging between 2.5 - 7 m. Purpose-made stop ends can be used to form the joints between adjacent panels, with a water bar incorporated across the joints. More complicated arrangements such as L or T-shaped panels can be constructed where additional bending moment capacity or wall stiffness is required.
Precast concrete diaphragm walls have the same advantages but are less flexible in terms of design. The units are installed in a trench filled with a special mixture of bentonite and cement with a retarder added to control the setting time. Ground anchors are used to tie the panels or posts to the retained earth to provide stability.
The high cost of diaphragm walls can make them uneconomic unless they can be incorporated into part of a building structure. As such, they are suited for deep basements, underground car parks and rail stations, tunnel approaches, underpasses, deep shafts for tunnel ventilation, pumping stations, and so on.
Sheet piles are sections of sheet materials with interlocking edges that are driven into the ground to provide earth retention and excavation support. Sheet piles are most commonly made of steel, but can also be formed of timber or reinforced concrete.
Sheet piles are commonly used for retaining walls, land reclamation, underground structures such as car parks and basements, in marine locations for riverbank protection, seawalls, cofferdams, and so on.
The selection of sheet piling is dependent on factors, such as:
The type of work, for example. whether it is permanent or temporary.
Site conditions. - The required depth of piles.
The required depth of piles. - The bending moments involved.
The bending moments involved. - The nature of the structure.
The nature of the structure. - The type of protection required.
The type of protection required. - Timber sheet piles
Timber sheet piles - Timber sheet piles are generally used for short spans in temporary structures, and to resist light lateral loads. They are typically connected together by tongue and groove joints. The disadvantage of timber piles is that they require preservative treatment and are not generally suitable for soils consisting of stones.
Timber sheet piles are generally used for short spans in temporary structures, and to resist light lateral loads. They are typically connected together by tongue and groove joints. The disadvantage of timber piles is that they require preservative treatment and are not generally suitable for soils consisting of stones.
Reinforced concrete sheet piles - Reinforced concrete sheet piles are formed using precast concrete members, usually connected together by tongue and groove joints. They are commonly used in permanent river embankments, canals and other marine structures. The toes of the piles are usually cut with an oblique face to facilitate easy driving and interlocking, while the heads are finished off by casting a capping beam.
Reinforced concrete sheet piles are formed using precast concrete members, usually connected together by tongue and groove joints. They are commonly used in permanent river embankments, canals and other marine structures. The toes of the piles are usually cut with an oblique face to facilitate easy driving and interlocking, while the heads are finished off by casting a capping beam.
Steel sheet piles - Steel is the most common form of sheet piles as it has good resistance to high driving stresses, excellent water-tightness, and can be increased in length either by welding or bolting. They are connected by interlocking.
Steel is the most common form of sheet piles as it has good resistance to high driving stresses, excellent water-tightness, and can be increased in length either by welding or bolting. They are connected by interlocking.
There are four basic forms of steel sheet piles:
Normal sections - These include Larssen and Frodingham sheet piles, which are systems of interlocking steel piles. They have good driving qualities and are designed to provide the good strength for low weight.
These include Larssen and Frodingham sheet piles, which are systems of interlocking steel piles. They have good driving qualities and are designed to provide the good strength for low weight.
The interlocking system facilitates easy positioning of the piles (pitching) and driving, as well as providing a close-fitting joint to form an effective water seal. In some cases, a sealant can be brushed into the joints prior to pitching which expands in thickness to form a watertight joint.
Larssen sheet piles are stronger and easier to drive because of their uniform section shape. Frodingham sheet piles are usually supplied interlocked in pairs, which makes them easier and quicker to handle and pitch.
Straight web sections - These are piles that are interlocked and driven to form cellular cofferdams which may be filled with material such as gravel and small rocks.
These are piles that are interlocked and driven to form cellular cofferdams which may be filled with material such as gravel and small rocks.
Box sections - These are formed by two or more sheet pile sections welded together, and are suitable when heavy loads and high bending moments are anticipated.
These are formed by two or more sheet pile sections welded together, and are suitable when heavy loads and high bending moments are anticipated.
Composite sections - These are commonly used in waterfront protection where large bending moments and heavy axial loads are anticipated. A typical composite pile is a double Frodingham section welded to the flange of a universal I-beam.
These are commonly used in waterfront protection where large bending moments and heavy axial loads are anticipated. A typical composite pile is a double Frodingham section welded to the flange of a universal I-beam.
Installation - Prior to installation, piles should be carefully inspected for straightness, cracks and the integrity of the interlocking components.
Prior to installation, piles should be carefully inspected for straightness, cracks and the integrity of the interlocking components.
Driving must be carefully monitored and should stop immediately if the pile ceases to penetrate the soil, before moving on to the next pile along. In some cases, several adjacent piles will be unable to penetrate to the design depth. At this point, effort should be made to remove the obstacle, either by partial excavation or using a water jet. There is an acceptable number of under-driven sheet piles, but this will vary according to the specific design requirements.
Sheet piles have a tendency to deviate from a vertical plane during driving and instead lean sideways. This is due to encountering obstacles within the soil which act as deflection. Guide controls should be used to counter this.
One technique is to drive piles in panels. This involves pitching and driving two piles to part or full-penetration at either end of a panel of piles. The panel is therefore supported by the bookended piles during driving to their final position. The pair left on the end then forms the support of the next panel along.
Another technique is to use trestles and walings to support and position sheet piles during driving.
Vibratory hammers are often used to install sheet piles, although if soils are too hard or dense, an impact hammer can be used. At certain sites where vibrations are a concern, the sheets can be hydraulically pushed into the ground.
Bored piles, also known as replacement piles, are a commonly-used form of building foundation that provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics.
Bored piles are piles where the removal of spoil forms a hole for a reinforced concrete pile which is poured in situ. The spoil is replaced by the pile, hence 'replacement' piles as opposed to displacement piles where soil is forced away by driving or screwing the pile.
Bored piles are used primarily in cohesive subsoils for the formation of friction piles and when forming pile foundations close to existing buildings. They are popular in urban areas as there is minimal vibration, where headroom is limited, where there is no risk of heave, and if there is a need to vary the length of the piles.
Installation - Bored piles are drilled using buckets and/or augers driven by percussion boring (vibratory hammers) or through rotary boring (twisting in place).
Bored piles are drilled using buckets and/or augers driven by percussion boring (vibratory hammers) or through rotary boring (twisting in place).
In unstable soil strata, the use of bentonite fluid assists in stabilising the bore especially in large diameter deeper piles and allows the insertion of heavily reinforcing steel cages. This is known as flush boring (see more below).
If the boring and pouring takes place simultaneously, piles are known as continuous flight auger (CFA) piles.
Piles are known as large diameter piles if they are 600 mm or more in diameter. Small diameter piles of less than 600 mm are sometimes placed in groups under a common pile cap to receive heavy loads.
Large diameter piles can have their bearing capacity increased by under-reaming the shaft at the base. This is achieved by an expanding cutting tool which cuts a conical-shaped base up to three times the diameter of the main shaft.
The form of support to the pile or borehole affects the pile formation. Bored piles can be either supported or unsupported.
Unsupported piles - Where piling is undertaken in stable soils it may be possible to bore and place the concrete without first lining the hole. However, precautions need to be taken by lining the first metre of the hole to prevent surface spoil from falling into the hole.
Where piling is undertaken in stable soils it may be possible to bore and place the concrete without first lining the hole. However, precautions need to be taken by lining the first metre of the hole to prevent surface spoil from falling into the hole.
Supported piles - There are two categories of supported pile depending on the casing or lining that is used.
There are two categories of supported pile depending on the casing or lining that is used.
Permanent casing - The borehole can be formed by the percussion method which involves a heavy cutting tool on a small tripod which is dropped from its raised position using a winch to cut out a cylinder of earth. The operation is repeated until the hole has been sunk to the required depth. As the cutting proceeds, a thin sectional lining is inserted into the hole to prevent its collapse. Alternatively, the borehole can be formed by the rotary method in which the rotary drill operates within the casing or lining.
The borehole can be formed by the percussion method which involves a heavy cutting tool on a small tripod which is dropped from its raised position using a winch to cut out a cylinder of earth. The operation is repeated until the hole has been sunk to the required depth. As the cutting proceeds, a thin sectional lining is inserted into the hole to prevent its collapse. Alternatively, the borehole can be formed by the rotary method in which the rotary drill operates within the casing or lining.
Temporary casing - It is common for the borehole to be supported by a screw-jointed steel lining which is removed either during or after the concrete has been placed. The tube can be winched or jacked out of the ground.
It is common for the borehole to be supported by a screw-jointed steel lining which is removed either during or after the concrete has been placed. The tube can be winched or jacked out of the ground.
Flush boring uses a fluid such as bentonite to flush material from the hole, which has been loosened by drilling. The fluid can be poured from above (reverse flushing) or pumped through the drilling rod (direct flushing). The bored hole is lined with a temporary steel casing to prevent collapse of loose surface soil. As the boring proceeds, bentonite is continuously fed into the hole.
At the required depth, reinforcement is lowered through the bentonite and concrete poured. The bentonite is displaced by the concrete and pumped back up out of the hole. As the concrete reaches the holes upper level, the temporary casing is withdrawn.
The term binder course refers to a European standard description of the second layer of asphalt pavement, described in the UK as a basecourse.
Cofferdams are temporary structures used where construction is being carried out in areas submerged in water. They are most commonly used to facilitate the construction or repair of dams, piers and bridges. The aim of a cofferdam is to be as watertight as possible to create a dry area in which to complete the required building works, or at least to limit water ingress to a safe level that can be pumped away.
Cofferdams must be able to withstand very high pressures and can create a hazardous situation if they are installed incorrectly. They are usually constructed using steel sheet piles driven into the ground and supported by internal braces and cross braces. Timber sheet piles, concrete or a combination of materials can also be used.
A cofferdam can be any shape. Its design will be depend on the depth required, the required working area, soil conditions, fluctuations in the water level, and so on.
Types of cofferdam - There are several different types of cofferdam. The most common are as follows:
There are several different types of cofferdam. The most common are as follows:
Typical piled cofferdam - The construction sequence for a typical piled cofferdam is as follows:
The construction sequence for a typical piled cofferdam is as follows:
Pre-dredge the proposed area of the cofferdam. - Drive temporary support piles into place.
Drive temporary support piles into place. - Install bracing frames to support piles.
Install bracing frames to support piles. - Drive sheet piles into place.
Drive sheet piles into place. - Pump out water from the inside of the cofferdam.
Pump out water from the inside of the cofferdam.
Progressively install internal bracing as required. - Excavate ditch to allow leakage to run to one place.
Excavate ditch to allow leakage to run to one place.
Place rock fill as a leveling and support course.
Earthen - This is a simple form of cofferdam suitable for areas of shallow water with low current velocity, where a sloped earthen embankment is built up around the area to be enclosed. The bank should be a combination of clay and sand or clay and gravel.
This is a simple form of cofferdam suitable for areas of shallow water with low current velocity, where a sloped earthen embankment is built up around the area to be enclosed. The bank should be a combination of clay and sand or clay and gravel.
Rock-fill - If the water to be retained is not shallow enough for an earthen cofferdam, stone or rubble can be used instead. The stones are built up in the required shape of the cofferdam, and voids filled with earth, gravel or stone-chips.
If the water to be retained is not shallow enough for an earthen cofferdam, stone or rubble can be used instead. The stones are built up in the required shape of the cofferdam, and voids filled with earth, gravel or stone-chips.
Single-walled - This type of cofferdam is most suitable when the area to be enclosed is particularly small and the water is of a deeper level, roughly 4-6 m. Guide piles made of timber are driven into the ground and bracing constructed before sheet piles are driven into place and secured to the bracing using bolts.
This type of cofferdam is most suitable when the area to be enclosed is particularly small and the water is of a deeper level, roughly 4-6 m. Guide piles made of timber are driven into the ground and bracing constructed before sheet piles are driven into place and secured to the bracing using bolts.
Double-walled - Single-walled cofferdams become unfeasible as larger areas are required in deeper water, and so double-walled cofferdams are sometimes necessary. Two walls are built with a gap between them, the thickness of which is dependent upon the depth of water.
Single-walled cofferdams become unfeasible as larger areas are required in deeper water, and so double-walled cofferdams are sometimes necessary. Two walls are built with a gap between them, the thickness of which is dependent upon the depth of water.
The general rule is for the thickness of the wall to equal the depth of water up to 3 m, greater depths require 3 m plus half the excess depth. The two wall faces are connected at the top using steel rods placed at close intervals.
Crib - This is commonly used in deep waters where the ground is particularly hard. The sheet piles are supported by a horizontal framework of timbers, known as cribs, which form pockets to be filled with earth or stones. This is constructed on land prior to being moved into position in the water. The crib is sunk into position, the internal space filled with stone or other material and timber or steel piles are then driven around the boundary of the crib.
This is commonly used in deep waters where the ground is particularly hard. The sheet piles are supported by a horizontal framework of timbers, known as cribs, which form pockets to be filled with earth or stones. This is constructed on land prior to being moved into position in the water. The crib is sunk into position, the internal space filled with stone or other material and timber or steel piles are then driven around the boundary of the crib.
Cellular - This type of cofferdam is most suitable for deep water areas, most commonly for during marine construction such as dams and wharves. Straight web steel sheet piles are driven into the ground to form a series of inter-connected cells of specific shapes which are filled with clay, sand or gravel to enable the structure to withstand the lateral forces of the water pressure. There are two common shapes:
This type of cofferdam is most suitable for deep water areas, most commonly for during marine construction such as dams and wharves. Straight web steel sheet piles are driven into the ground to form a series of inter-connected cells of specific shapes which are filled with clay, sand or gravel to enable the structure to withstand the lateral forces of the water pressure. There are two common shapes:
Circular type: Each cell acts as a self-supporting independent unit so each cell can be completely filled before construction of the next cell begins.
Diaphragm type: Made from interconnected steel sheet piles using circular arcs at the inner and outer sides. The cells are then filled with coarse-grained soils, all at the same rate to avoid rupturing.
Driven piles, also known as displacement piles, are a commonly-used form of building foundation that provide support for structures, transfering their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics.
Driven piles are commonly used to support buildings, tanks, towers, walls and bridges, and can be the most cost-effective deep foundation solution. They can also be used in applications such as embankments, retaining walls, bulkheads, anchorage structures and cofferdams.
A foundation is described as piled when its depth is more than three times its breadth (Atkinson, 2007). A driven pile is a long, slender column made of preformed material and having a predetermined shape and size that can be installed by impact hammering, vibrating or pushing it into the ground to a design depth or resistance. If the soil is particularly dense, pre-drilling may be required to enable the pile to reach the design depth.
Driven piles are very adaptable and can be installed to accommodate compression, tension or lateral loads, with specifications set according to the needs of the structure, budget and soil conditions.
Types of driven pile - Types of driven pile include:
Types of driven pile include: -
Steel - Standard steel sheet pile sections can be used to form box section piles, or H-section piles. These are percussion driven and used mainly in connection with marine structures. These have a load range of 300-1,700 kN and can reach up to 36 m length.
Standard steel sheet pile sections can be used to form box section piles, or H-section piles. These are percussion driven and used mainly in connection with marine structures. These have a load range of 300-1,700 kN and can reach up to 36 m length.
Steel screw piles have a cast iron helix, are rotary driven, and are used for support at shallow depths in soft silts and sands. They have a load range of 400-3,000 kN and can reach up to 24 m length. For more information, see Screw pile foundations.
Steel tube piles are used on marine structures and foundations in soft subsoils over a suitable bearing strata. They are usually bottom-driven with an internal drop hammer.
Pre-cast concrete - These can be square, octagonal, cylindrical or sheet piles. They are percussion driven piles which are used where bored piles would not be suitable owing to running water or very loose soils. They have a load range of 300-1,200 kN and can reach up to 30 m.
These can be square, octagonal, cylindrical or sheet piles. They are percussion driven piles which are used where bored piles would not be suitable owing to running water or very loose soils. They have a load range of 300-1,200 kN and can reach up to 30 m.
Timber - These are usually square sawn (but can also be circular, tapered, treated, untreated), and percussion driven. They can be used for small contracts on sites with shallow alluvial deposits overlying a suitable bearing strata (e.g. river banks and estuaries).
These are usually square sawn (but can also be circular, tapered, treated, untreated), and percussion driven. They can be used for small contracts on sites with shallow alluvial deposits overlying a suitable bearing strata (e.g. river banks and estuaries).
The load range of timber piles is 50-350 kN. They can be up to 12 m in length without splicing.
Composite - These are piles that use a combination, such as a concrete pile with a steel tip extension.
These are piles that use a combination, such as a concrete pile with a steel tip extension.
Quality - Driven piles are built to precise tolerances using high-strength materials and require good quality control. Consistency of quality is achieved by conforming to BS 8004:2015 as well as EC standards, and inspection prior to installation to verify integrity.
Driven piles are built to precise tolerances using high-strength materials and require good quality control. Consistency of quality is achieved by conforming to BS 8004:2015 as well as EC standards, and inspection prior to installation to verify integrity.
It is important that driven piles maintain their shape during installation, and are not damaged by the installation of subsequent piles.
Static or dynamic pile testing can be used to verify pile capacity, that is, the maximum load that a pile can carry without failure or excessive settlement of the ground. Pile capacity depends on three primary factors:
The type of soil through which the pile is driven.
The method of pile installation. - The pile dimensions (cross section and length).
The pile dimensions (cross section and length).
The shaft soil strength usually increases with time post-installation to provide additional load capacity. When incorporated into foundation design, this so-called setup can enable the installation of fewer and shorter piles which results in less time, labour and materials being employed.
Pile installation - A pile hammer is used to drive piles into the ground, which compacts the soil around the side and leads to densification of the mass and increases its bearing capacity. However, with saturated, silty or cohesive, as opposed to granular, soil, poor drainage quality does not allow for the same densification. The water in the soil leads to a decrease in the overall bearing capacity and the pile design must allow for this.
A pile hammer is used to drive piles into the ground, which compacts the soil around the side and leads to densification of the mass and increases its bearing capacity. However, with saturated, silty or cohesive, as opposed to granular, soil, poor drainage quality does not allow for the same densification. The water in the soil leads to a decrease in the overall bearing capacity and the pile design must allow for this.
The blow count is the number of times the pile must be struck in order to be driven down to the desired depth. Where there are variations in the subsurface conditions, pile lengths may have to be cut-off or spliced to extend their length.
As there are no special casings required and no delays related to concrete curing, driven piles are well suited to difficult site conditions. They can be used immediately when driven through water, can be installed to create temporary work platforms, and used in a large diameter form in earthquake-prone regions.
Advantages and disadvantages - The main advantages of using driven piles are:
The main advantages of using driven piles are:
Piles can be pre-fabricated off-site which allows for efficient installation once on site.
Driven piles displace and compact the soil which increases the bearing capacity of the pile. Whereas, other deep foundations tend to require the removal of soil which can lead to subsidence and other structural problems.
They are cost-effective as a wide variety of materials and shapes can be easily fabricated to specified dimensions, which can result in the need for fewer piles on site.
They generally have superior structural strength to other forms of foundation. Their high lateral and bending resistance makes them ideal for challenging conditions such as wind, water, seismic loading, and so on.
Installation usually produces little spoil for removal and disposal.
The main disadvantages of using driven piles are:
Advance planning is required for handling and driving, as well as the heavy equipment on site.
To be able to withstand handling stresses during transportation and installation, precast or pre-stressed concrete piles must be adequately reinforced.
It may not be possible to determine the exact length required and so splicing or cut-off techniques may be required which has time and cost implications.
Driven piles may not be suitable where the ground has poor drainage qualities.
Driven piles may not be suitable for compact sites, where the foundations of structures in close proximity may be affected by the vibrations caused by installation.
Driven piles can be noisy to install and vibrations can result in complaints from neighbours, who may become aware of pre-existing problems with their own building that they then blame on piling vibration.
A caisson is a box-like structure commonly used in civil engineering projects where work is being carried out in areas submerged in water. Such projects might include:
Bridge piers. - Abutments in lakes and rivers.
Abutments in lakes and rivers. - Break water and other shore protection works.
Break water and other shore protection works. - Wharves and docks.
Wharves and docks. - Large water front structures.
Large water front structures. - Caissons differ from cofferdams in that cofferdams are removed after completion of the work, whereas caissons are built to remain in place as a part of the completed structure.
Caissons differ from cofferdams in that cofferdams are removed after completion of the work, whereas caissons are built to remain in place as a part of the completed structure.
Caissons can be made of materials including timber, steel, masonry and reinforced concrete, and may be constructed onshore then floated to the required location, where they are sunk into place, enabling access to the bed and excavation of foundations to the required depth.
They are particularly suitable for the construction of underwater foundations or where the water is deep, as they are strong enough to withstand significant vertical and horizontal loads, as well as lateral forces such as waves.
Types of caisson - There are several different types of caisson, the choice of which will depend upon the structure for which it is being built as well as the required depth. Some of the more most common types are describes below:
There are several different types of caisson, the choice of which will depend upon the structure for which it is being built as well as the required depth. Some of the more most common types are describes below:
Box caisson - This is a watertight timber or reinforced concrete box with a closed bottom and an open top. The caisson is cast and cured on land and then sunk into place, or it can be rested on top of a pile formation. Sand, concrete or gravel is used to weigh down and sink the caisson. This is most suitable for areas where the bearing strata is reasonably level and no excavation is required, although it is possible for some dredging to further level the base if required to avoid the tilting of the caisson once in place.
This is a watertight timber or reinforced concrete box with a closed bottom and an open top. The caisson is cast and cured on land and then sunk into place, or it can be rested on top of a pile formation. Sand, concrete or gravel is used to weigh down and sink the caisson. This is most suitable for areas where the bearing strata is reasonably level and no excavation is required, although it is possible for some dredging to further level the base if required to avoid the tilting of the caisson once in place.
This type of caisson is generally relatively economical but may not be suitable if the bearing strata requires compacting and/or levelling.
Open caisson - This is a timber, steel or concrete box that is open at both the bottom and the top. The walls are heavy and made with sharp edges that facilitate the sinking process. There are three different types of open caisson:
This is a timber, steel or concrete box that is open at both the bottom and the top. The walls are heavy and made with sharp edges that facilitate the sinking process. There are three different types of open caisson:
Single wall - As opposed to box caissons which are prefabricated, open caissons are formed in situ. Wherever possible, a temporary cofferdam is constructed to keep the working environment dry and to enable the excavation of a pit in which the caisson is to be sunk, either by its self-weight, by concrete or by the use of hydraulic jacks if the skin friction prevents it from sinking. The soil from the space inside the caisson can then be removed by a clamshell excavator bucket on a crane.
As opposed to box caissons which are prefabricated, open caissons are formed in situ. Wherever possible, a temporary cofferdam is constructed to keep the working environment dry and to enable the excavation of a pit in which the caisson is to be sunk, either by its self-weight, by concrete or by the use of hydraulic jacks if the skin friction prevents it from sinking. The soil from the space inside the caisson can then be removed by a clamshell excavator bucket on a crane.
The sinking proceeds at the rate necessary to allow each section to be concreted to a sufficient strength. Once sunk to the required depth, the base is plugged with a thick seal of concrete and once set the internal water is pumped out, to be replaced with sand, gravel or concrete.
Cylindrical (or well) - This is a cylindrical shell made of timber, masonry, steel or reinforced concrete. The wall must be sufficiently thick so that when the soil from inside is excavated, it sinks under its own weight. A cutting edge on the base of the walls and water jets can be used to assist sinking and reduce the level of skin friction. Once sunk to the required depth, the bottom is sealed with concrete.
This is a cylindrical shell made of timber, masonry, steel or reinforced concrete. The wall must be sufficiently thick so that when the soil from inside is excavated, it sinks under its own weight. A cutting edge on the base of the walls and water jets can be used to assist sinking and reduce the level of skin friction. Once sunk to the required depth, the bottom is sealed with concrete.
Open with dredging wells - This method is commonly used for the deepest foundations, such as bridge piers and abutments. The outside walls, as well as inside divider walls which make up smaller sections (or wells), are made of reinforced concrete. Dredging the soil out through the wells enables the caisson to sink. Once sunk to the required depth, a concrete seal is installed and the walls filled with sand or concrete.
This method is commonly used for the deepest foundations, such as bridge piers and abutments. The outside walls, as well as inside divider walls which make up smaller sections (or wells), are made of reinforced concrete. Dredging the soil out through the wells enables the caisson to sink. Once sunk to the required depth, a concrete seal is installed and the walls filled with sand or concrete.
Pneumatic caisson - Pneumatic caissons are closed at the top but open at the bottom, with the water forced out using compressed air, creating a working chamber which is airtight in order for excavation to be carried out. This is suitable when it is not possible to excavate wet ground in the open.
Pneumatic caissons are closed at the top but open at the bottom, with the water forced out using compressed air, creating a working chamber which is airtight in order for excavation to be carried out. This is suitable when it is not possible to excavate wet ground in the open.
To facilitate the internal work, the caisson has two air locks that consist of a steel chamber and two air-tight doors. One air lock allows labourers to enter and exit, and the other is used for removing the excavated material. It is important that the air pressure must be carefully monitored at all times, with slow raising and lowering as the labourers enter and leave the chamber. Otherwise, there is the risk of labourers suffering with caisson disease which results from the expansion of air bubbles trapped in joints and muscles.
Although this method is suitable for difficult locations, such as depths ranging from 25-40 m, it is a complex, slow and expensive procedure.
Within The Green Guide to Specification (4th edition), biomaterials are classed as naturally-derived construction materials (ie those originating from plant or animal sources) providing both structural and non-structural functions within the building fabric. Biomass is a biological material used as a fuel. This is often used to mean plant-based material, but biomass can equally apply to both animal and vegetable-derived materials.
For example, sawn softwood timber used in the construction of timber frames or as studwork is categorised as biomaterial due to the structural function it is fulfilling. However, wood such as poplar or willows grown specifically to generate electricity or produce heat through direct incineration is classed as biomass.
Biomaterials most commonly used in UK construction are solid timber, timber products such as wood-based panels, cellulose, plant fibres and animal fibres.
Ground heave is the upward movement of the ground usually associated with the expansion of clay soils which swell when wet. As the soil generally cannot expand downwards or sideways, the result is that the exposed upper surface of the soil rises up. The impact of heave is opposite to the effect of subsidence which is where soil is unstable and sinks downward, or settlement which is caused by the weight of a building.
Displacement is generally less than 150 mm, however, even this level of movement can lead to serious structural damage to building foundations and fabric. Long-term damage could be incurred that may not be detected for some time, but can significantly affect a propertys value.
Causes of ground heave - The most common cause of ground heave is associated with trees which have died or been removed. As the root network no longer draws water from the subsoil, water accumulates in the ground, resulting in swelling that can move building structures upwards.
The most common cause of ground heave is associated with trees which have died or been removed. As the root network no longer draws water from the subsoil, water accumulates in the ground, resulting in swelling that can move building structures upwards.
Additional causes of ground heave may include: -
Stress relief (or overburden recovery) attributable to soil being removed from an excavation and so relieving pressure on layers below. This may occur for example in the construction of basements.
A change in the level of the water table.
Broken drains or nearby building works that interfere with existing ground drainage.
Swelling of the sub-soils due to seasonal weather changes.
Water expanding as it freezes causing soil to swell. Some particular soils, such as silty and sandy clays, can be more susceptible than others.
Signs of ground heave - Common signs of ground heave may include:
Common signs of ground heave may include: -
Cracking to brickwork and windows. This cracking is more likely to be vertical, whereas subsidence cracking is more likely to be diagonal.
Doors sticking as their frames become out of square.
Lifting of paths and patios surrounding buildings. - Prevention and remedying of ground heave
Prevention and remedying of ground heave - Surveys will indicate whether heave has occurred that may impact upon a building, and may advise, for example, on the potential risks of proposed works such removing trees near buildings. Investigations may include visual inspection, historic research and drilling boreholes to determine the moisture profile of the soil.
Surveys will indicate whether heave has occurred that may impact upon a building, and may advise, for example, on the potential risks of proposed works such removing trees near buildings. Investigations may include visual inspection, historic research and drilling boreholes to determine the moisture profile of the soil.
Where heave is likely to be a problem, cellular structures may be installed beneath foundations and floor slabs to reduce the upward force of heave from transmitting to the structure above. For more information, see Cellular raft foundation.
Remedying damage due to ground heave can be a lengthy and expensive process. Where heave is the result of an underlying problem, remedial works such as repairing leaking drains or removing vegetation may resolve the problem.
Where the soil itself is prone to heave, underpinning may be necessary to stabilise structures. Excavated soil from beneath existing foundations is replaced with material, usually concrete, in a series of phases to form a new foundation beneath the existing one, reaching down to subsoils that are not prone to heave. It may be necessary to leave a cavity beneath the structure to accommodate future movement of the upper layers of soil.
A blind arch is an arch that has been built within a wall and infilled, as opposed to traditional arches that are left open for use as passageways, windows, and so on. They can be built with solid infill as an intentional design aesthetic, or built as an open arch and infilled later. A blind arch can be used internally and externally, but is most commonly built into the external faade as a form of decoration, or in combination with functional archways which permit access or serve as windows.
Gothic and Romanesque Revival architecture commonly feature blind arches, most typically constructed from masonry or stone. They can also be found, in simulated form, in more modern light frame construction.
The term 'blind arcade' refers to a series of blind arches in a row.
The infill material is often the same as is used for the surrounding wall element. The thickness of the filled section can be the same or differ from that of the wall. A thinner infill can be used to provide the faade with depth and profile. A thicker infill may be found where the arch has been filled for security reasons, or to preserve a structure that is crumbling or otherwise defective.
Some blind arch designs include a rounded top positioned above a standard door or window-sized opening. Other designs, such as in Middle Eastern architecture, may be more ornate and elaborate, with pointed or peaked tops. In Islamic designs, a decorative element known as tracery often covers a blind arch. Tracery is formed by bands of material arranged over a blind arch to create intricate patterned designs.
A blind arcade is a series of blind arches that are filled-in instead of being left open as with traditional arcades. Rather than having a load-bearing function, a blind arcade is often included in masonry facades as an ornamental element, with well-defined columns.
Blind arcades are common decorative features in Romanesque and Gothic architecture throughout Europe, as well as being found in Byzantine Orthodox and Armenian churches.
A variation of the blind arcade is the raking blind arcade which is a blind arcade that is slanted to varying degrees.
In construction, 'blinding' typically refers to a base layer of weak concrete or sand that is laid above a layer of hardcore to provide a clean, level and dry working surface.
A thin layer, usually around 50 mm (2 inches) thick, of blinding is poured over the hardcore, sealing in the underlying material and levelling off the surface.
If a damp-proof membrane (DPM) is to be placed above it, the blinding will help prevent it from becoming damaged by the hardcore. If a damp-proof membrane is not being laid directly above the blinding, the blinding instead provides a sturdy surface on which reinforcement for a concrete floor or raft foundation can be positioned, it prevents the concrete from seeping down into the hardcore, and it reduces the amount of moisture penetrating up into the concrete.
The concrete used for blinding is weak compared with structural concrete, and can withstand lower loading. If necessary, steel mats can be used to reinforce either the entire blinding layer or the specific areas of high loading.
NB Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines blinding as: A temporary accumulation of impermeable debris on the lower part of a screen that creates a weir effect, reducing the flow area and increasing upstream water levels. Preferred term is variable blockage. Where a screen is: An arrangement of bars, grids or poles placed in a watercourse.
Block planning is an industrial planning system used for in-house production. A product type can be produced in different variations using the same resources and following the same basic process plan. Block planning supports the production planning and scheduling for this type of system. A block represents a pre-defined sequence of production orders of variable size.
Block planning enables the planning or pre-assignment of resource capacities in the production process for products with specific attributes. It enables a more rational and efficient use of those capacities. Blocks are defined with specific duration and attributes, for example, three days per block on which products are manufactured in various colours.
In piece-oriented sectors such as metal and paper production, upstream planning is often used to define the type of products and which attributes are to be produced. This typically relates to plant needing to be set up in a particular way, when it is inefficient in terms of time and costs to change the set-up more than is necessary.
There is more emphasis, in piece-oriented production, on the resource for which only one production step is executed. It is usual for an order for run over several resources, in which each of the operations could be grouped according to different aspects.
By contrast, the process industry commonly groups several orders together as a campaign, which is more defined by the material characteristics of the end product. The emphasis is more on an order level, as the process cannot normally be interrupted once it has begun.
Blue roof - A blue roof is a roof designed for the retention of rainwater above the waterproofing element of the roof. This is as opposed to more conventional roofs which allow for rainwater to drain from the roof. Blue roofs are typically flat, without any fall, with control devices regulate drainage outlets that enable water to be retained or drained.
A blue roof is a roof designed for the retention of rainwater above the waterproofing element of the roof. This is as opposed to more conventional roofs which allow for rainwater to drain from the roof. Blue roofs are typically flat, without any fall, with control devices regulate drainage outlets that enable water to be retained or drained.
The SuDS Manual published by CIRIA in 2015 suggests that a blue roof is: A roof construction that stores water, can include open water surfaces, storage within or beneath a porous media or modular surface or below a raised decking surface or cover.
Some of the reasons for incorporating a blue roof into a building, include:
As a form of Sustainable Urban Drainage System (SuDS) to try and alleviate urban flooding caused by stormwater run-off.
In areas of urban density, the space created by a blue roof can avoid having to provide attenuation for rainwater at ground level.
Rainwater harvesting for use, independent from, or supplemental to the mains water supply, such as wc flushing or green roof irrigation
Cooling solar panels, or reducing load on mechanical refrigeration or cooling equipment.
For recreational purposes, such as rooftop swimming pools or water features.
Unlike some other forms of SuDS, blue roofs make use of spaces that might otherwise be redundant without extending beyond the footprint of the building or into ground space which, depending on the density of the location, may be expensive.
To ensure safety, there must be careful estimation of the flow restriction, which calculates the peak rates of run-off and the water depth that will be formed on the roof surface. This informs the design of the safety overflows, the preventative maintenance programme, and the design and construction of the waterproofing layer.
A cold roof is roof in which the thermal insulation layer is located immediately above or between the ceiling joists meaning that everything above the insulation, such as the rafters, and any roof space, will be colder than the living space below it.
When warm, damp air permeates up through the ceiling and reaches the cold roof space, the change in temperature can result in condensation forming. Adequate roof space ventilation must be provided therefore to remove this air. This requirement, and the need for preventative measures to tackle cold bridging, means that warm roofs can be preferable.
A warm roof is one in which the insulation layer is laid on top of roof structure (or above the loft or attic space in the case of pitched roofs) so that the roof structure or roof space is closer to the inside temperature and so the risk of condensation is reduced.
Particular care must be taken when installing loft insulation, as this can convert a pitched roof from a warm to a cold roof. Ventilation must then be provided to prevent the accumulation of moist air and so condensation, as this can cause the roof structure to deteriorate and ultimately to fail.
Blockboard is a timber-based sheet material that comprises a core faced on both sides. The core is made from parallel, rectangular-section, bonded softwood strips (around 28mm wide); these are sandwiched between a variety of facing materials which can include veneers of softwood, hardwood, thin MDF or particle board. The assembly is glued under high pressure.
The construction can be three-layer with a single facing on each side of the core, e.g MDF or particleboard, or it can be five-layer for better stability with two facings on each side. The grain of the facing material is usually arranged so that it is perpendicular to that of the core strips which for reasons of strength run along the length of the board and are usually made from seasoned, lightweight timbers, such as poplar or spruce. Their moisture content is usually 12% or less.
Like chipboard, blockboard is used mainly for interior uses due to the nature of the adhesives used. But in contrast to chipboard, blockboard has great structural stability and strength and is suited to applications such as doors, shelves, tables, panelling, partitions or kitchen worktops which have no intermediate supports.
Blockboard also forms a good base material for veneering, but the edges will have to be lipped with solid wood. It can also be painted after a light sanding but the edges will still require lipping or alternatively filling and sanding.
Blockboard is commonly available in 2,440mm x 1,220mm sheets (based on the imperial 8ft x 4ft dimensions) and in thicknesses of 18mm and 25mm.
Blockboard can be worked with standard tools: it is easily sawn and has good screw-holding and nail-holding properties. It can be resistant to warping if both sides have similar treatments. It can also be boiling water-proof and 'eco-friendly'.
Cedar is a type of coniferous wood, meaning that it is classified as a softwood and its cones/needles remain all year round. Cedar trees fall under the Cedrus genus and the Pinaceae family, which is the family of trees that is coniferous.
Only a couple of species of Cedrus exist in the world, but they exhibit certain traits that make them very popular.
Cedars are naturally found at high altitudes; over 1,500m in the Himalayas, and 1,000m in the Mediterranean. Compared to a tree within the same family, such as pine, cedars are generally quite small. They typically grow to around 35m, but larger in some circumstances. They have a natural spicy scent, thick bark, and broad branches. The leaves of a cedar are needle-like and can grow up to 6cm long.
Cedar wood and cedar oil are natural moth repellents, which is why cedar is commonly used for creating modern-day hope chests and closets that contain woollen clothes.
There are some types of cedar located in North America that are lightweight but also durable and highly stable. Because of this, it is used as wood shingles, which are tapered pieces of wood that clad roofs and walls to protect them from harsh weather.
Various types of cedar have a beautiful colour associated with them, but they are also resistant to warping and cracking, making them perfect for musical instruments. Instruments such as Spanish classical guitars and occasionally steel string guitars are made from cedar, however the type of cedar that is used is known as Western Red Cedar, which isn't a true cedar, such as the ones aforementioned.
Because of its resistance to warping, cedar can also be used for interior panelling in rooms around the house.
A boiler is a piece of technical apparatus in which fuels are oxidised to generate thermal energy, which is transferred to water or steam. Boilers are typically used to heat water to feed heating systems or to supply hot water, or both. Boilers are most commonly fuelled by:
Mains gas - Liquid petroleum gas (LPG).
Liquid petroleum gas (LPG). - Wood.
Wood. - Coal.
Coal. - Oil.
Oil. - Electricity.
Electricity. - There are a very wide range of boilers available depending on; size, fuel type, efficiency and application, and ranging from compact units used for domestic heating, to very large boilers used for industrial processes. For more information, see:
There are a very wide range of boilers available depending on; size, fuel type, efficiency and application, and ranging from compact units used for domestic heating, to very large boilers used for industrial processes. For more information, see:
Biomass boiler - CHP boiler
CHP boiler - Types of domestic boiler
Types of domestic boiler - Boiler efficiency
Boiler efficiency - Condensing boiler
Condensing boiler - Types of heating system.
Types of heating system. - Thermostat.
Thermostat. - An automatic feed boiler is a boiler with fully automated fuel supply.
An automatic feed boiler is a boiler with fully automated fuel supply.
Improved efficiency of new boilers - Heating accounts for a large portion of household expenses, especially during the winter. But if your energy costs are higher than normal, it may be due to an aging boiler. Boilers gradually become less efficient over time and often require more maintenance.
Heating accounts for a large portion of household expenses, especially during the winter. But if your energy costs are higher than normal, it may be due to an aging boiler. Boilers gradually become less efficient over time and often require more maintenance.
Replacing an old boiler with a new one means improved efficiency and lower emissions as a result. The Energy Saving Trust estimates that new boiler installations can potentially save households hundreds of pounds a year in energy costs alone.
Installations that meet safety regulations - All boiler installations must meet building and safety regulations. All boiler engineers must deliver professional new boiler installations that meet all safety requirements as established by the government. Most engineers are Gas Safe Registered and properly insured with public liability insurance.
All boiler installations must meet building and safety regulations. All boiler engineers must deliver professional new boiler installations that meet all safety requirements as established by the government. Most engineers are Gas Safe Registered and properly insured with public liability insurance.
Boiler replacement costs vary, as every home has different heating requirements. Upfront costs may seem hefty, but replacing an aging boiler is well worth the investment in the long term. A more efficient boiler means greater energy savings.
Request a consultation - If youre considering installing a new boiler, contact a boiler engineer for a consultation and a written estimate for your new boiler. In some cases, they will also give recommendations such as a power flush to remove any sludge and debris that could be affecting how your boiler runs.
If youre considering installing a new boiler, contact a boiler engineer for a consultation and a written estimate for your new boiler. In some cases, they will also give recommendations such as a power flush to remove any sludge and debris that could be affecting how your boiler runs.
There is an extensive process to assess your entire central heating system and determine the work involved. This allows a more accurate quote to be provided, and the recommendation of a new boiler for your living space.
Engineers can help you with the following services:
Boiler Installations - Boiler Servicing
Boiler Servicing - Eco Boilers
Eco Boilers - Boiler Relocations
Boiler Relocations - Heating Upgrades
Heating Upgrades - Plumbing
Plumbing -
Breakers, also known as a hammers or hoe rams, are powerful percussion tools used for breaking up concrete or rock. They can be fitted to excavators and are powered by auxiliary hydraulic systems. They are similar in function and operation to hand-held pneumatic drills.
Breakers are typically used in application such as:
The demolition of buildings. - Breaking up pavements or roads.
Breaking up pavements or roads. - Trenching in rock.
Trenching in rock. - Breaking frozen ground
Breaking frozen ground - Secondary reduction of blasted material.
Secondary reduction of blasted material. - There are two basic designs for mounted breakers side-plate and boxed:
There are two basic designs for mounted breakers side-plate and boxed:
Side-plate breakers have two slabs of steel secured to either side of the breaker mechanism. This arrangement usually leaves the breakers front and back open.
Boxed breakers enclose the breaker mechanism in an outer casing, which acts as a shock-absorbing barrier. This has the advantage of providing more protection from debris. They also tend to be quieter, and there is a reduction in shock and vibration.
Breaker manufacturers tend to use an Impact Energy Class rating to identify different breakers, which is loosely based on the breakers weight.
Breakers can also be categorised based on the piston-firing system that they use. The three basic types are:
Nitrogen-gas. - Hydraulic-oil.
Hydraulic-oil. - Combination nitrogen-gas and hydraulic-oil.
Combination nitrogen-gas and hydraulic-oil. - The working tool should be sufficiently lubricated, and cleaned from abrasive dust that can get into the lower portion of the breaker. Some breaker models are fitted with automatic lubrication systems, or a sealing system can be installed if required.
The working tool should be sufficiently lubricated, and cleaned from abrasive dust that can get into the lower portion of the breaker. Some breaker models are fitted with automatic lubrication systems, or a sealing system can be installed if required.
A brick veneer, also known as a brick slip, is a thin layer of brick that is used aesthetically as a form of surface finish rather than structurally. Conventional brick walls typically support the structural loads of the building, whereas brick veneers are applied for decorative purposes.
They are generally formed from thin brick slips, which may be as little as 20 mm thick (compared to 102.5 mm for a standard brick). Brick veneers can be used for both indoor and outdoor applications and can be applied to almost any surface. A range of special brick slips are available for conditions such as corners, to continue the illusion that walls are constructed from full bricks.
For interior applications, such as around fireplaces, brick veneers may laid in a similar way to tiles. Mortar (or some other adhesive) is spread on the wall and the bricks are set into place on it, separated during drying by plastic spacers. Once bed mortar has set, the brick joints are pointed using more mortar. Other 'veneers' are available in rolls, as a form of three-dimensional wallpaper.
For exterior applications, the veneer may be laid in a similar way to internal applications, as a form of cladding. However, they may also be installed as a free-standing panels (often prefabricated off site, and sometimes including other components such as insulation), anchored back to the structural frame. This type of veneer is vertically self-supporting, but in multi-storey buildings, shelf angles may be used to provide a horizontal expansion joint, usually at the floor edges. This allows for expansion of the brick and potential shrinkage of the frame.
There are several advantages to using brick veneers:
They are relatively easy and quick to install.
They are not as heavy as other forms of masonry, which reduces structural loading.
Cavities behind external brick veneers can aid insulation.
They are durable and fire-resistant. - They can achieve a wide range of decorative functions
They can achieve a wide range of decorative functions
They require little maintenance. - Disadvantages include:
Disadvantages include: -
They are more susceptible to damage as they are thinner than conventional brick walls.
They do not contribute to structural integrity. - They can be susceptible to water damage.
They can be susceptible to water damage. - Over time, the veneer will require re-pointing with new mortar.
Over time, the veneer will require re-pointing with new mortar.
Quoins are large rectangular blocks of masonry or brick that are built into the corners of a wall. They can be used as a load-bearing feature to provide strength and weather protection, but also for aesthetic purposes to add detail and accentuate the outside corners of a building.
It is usual for quoins to be arranged in a toothed form, with alternate quoins projecting and receding from the corner. Where quoins are used purely for decorative reasons, a wide range of materials can be used such as timber, cement render, and stucco. They are often coloured to compliment the brickwork or render of the building.
There are a number of different types of quoin:
Return quoin: The standard type, is built into wall corners with one long side over one short side.
Reveal quoin: Built into the wall as a standard block, commonly used for door and window reveals.
Chamfered quoin: This quoin has a chamfered edge on the top, bottom and outside edges for aesthetic purposes. This can also be incorporated on reveal, return or cladding-type quoins.
Cladding quoin: This quoin is fixed onto the wall using a two-part resin after the corner has been finished. It is usually 50 mm thick. If the wall is to be rendered, the quoins are fixed first and then the render brought up to the chamfer.
In classical architecture, rustication is a type of decorative masonry that provides a purposefully rough or patterned surface for exterior masonry walls. The technique used for rustication is to cut the visible face of each individual masonry block back at the edges to a plane surface, leaving the central portion of the face projecting outwards. Rustication is typically used on the ground floor level, often as a means of contrasting visually with smoothly-finished masonry surfaces known as ashlar.
As a technique, rustication was used in ancient Greek, as well as Roman and medieval, architecture. It was later revived for the period of Italian Renaissance architecture where it can be seen on palaces such as the Pitti Palace and the Medici-Riccardi Palace, both in Florence, Italy. Inigo Jones was responsible for introducing rustication to England in the 17th century, and it became a common feature in English stonework during the 17th and 18th centuries.
Stucco is a term commonly used for Portland cement plaster which can be used as an exterior finish for buildings. It consists of Portland cement-based materials and sand, mixed with water to form a plaster. The advantages of stucco are that it is cost-effective, versatile and durable.
The terms render and stucco are sometimes used interchangeably, with render being the more commonly used term in the UK, and stucco (of German origin) more commonly used in the USA and in Europe, where it can also refer to plaster used for internal walls. However, very generally, render tends to contain more sand than stucco.
Stucco is porous and adheres well to concrete and masonry surfaces. However, application can be problematic if there is contamination present on the substrate surface, which is generally not a problem for new walls but can be with older walls that have paint, sealer or some other coating on the surface. If uniform bonding is not achieved in the application of stucco, stresses can lead to delamination and cracking.
The substrate can be washed to remove contamination or techniques such as sandblasting or acid etching may be required. Alternatively, a dash-bond coat or a bonding agent can be used to allow for the direct application of stucco. If this still does not make the surface ready, paper-backed lath can be used to mechanically anchor and support the weight of the stucco.
Before beginning the application of stucco, the surface should be pre-wetted with water which reduces its water demand by preventing water from the stucco being drawn into dry pores, and the potential of premature dry-out. Generally, stucco is applied directly to solid surfaces in two coats, starting from the bottom and working towards the top.
Stucco can be used for a wide range of architectural aesthetics, with colour additives and various textures. By applying texture through the selection of aggregate size and controlling the finish mix consistency, highlights, depth, segmentation and patterns can be provided to the surface of the stucco.
Portland cement-based paints can be used on stucco effectively. Paint is scrubbed into the surface and fully cured. An alternative is a coloured stucco finish which can be made with white cement and pigments.
A bricklayer is a craftsperson who lay bricks, generally with mortar, to create finished construction works, such as walls, chimneys, parapets, spandrel panels and so on. In the UK and Australia, bricklayers are colloquially referred to as brickies.
Bricklayers also repair and maintain masonry structures and will also often be skilled in laying concrete blocks, as constructing a cavity wall, for example, will usually involve parallel brick and block wall components.
The bricklayers profession ranks among one of the oldest bricks have been excavated at Jericho, Israel that date from around 8,000 BC. The Egyptians and Romans were keen bricklayers, as have been the British, who have used brick almost continuously from the 15th century. The bricklayers art was refined and taken to new heights by the Victorians in the 19th century.
From 2000 onwards, the UK has experienced a severe shortage of bricklayers at a time when the education education, education mantra of the Labour government highlighted the desirability of a university education. By implication, trades occupations were perceived to have a much lower social status. This encouraged many more students to take up full-time university courses and fewer to go into trades. The result was a shortages not only of bricklayers, but also plumbers, plasterers, carpenters and other building trades. So much so, that the lack of skilled workers has held back building work and increased labour costs.
Building wraps are large-scale printed sheet materials that can be fixed to scaffolding structures and used to conceal building work. They are commonly digitally printed with a CGI rendering or photographic image of the building faade, attempting in some way to blend in better with its context than traditional debris netting would.
It is a technique that is sometimes used on important buildings, or in sensitive locations, to hide unsightly scaffolding while providing a tantalising representation of what the building looks, or will look, like.
The benefits of building wraps are that they can help to reduce the spread of dust and other debris, conceal construction work from the public, and mean that views of the under-construction building is minimised.
The scaffolding must be securely erected for the building wrap to be installed. If necessary, engineers must calculate wind loading to be ensure that the installation of the wrap will not be a hazard to the scaffolding.
Building wraps are typically installed onto a 'picture frame' scaffold structure which projects about 300 mm further out than the last projected pole on the main scaffolding. Any projecting scaffold poles should be capped to cover sharp ends. This allows the wrap banner to move with the wind without getting caught on any poles which can cause damage.
Two commonly used fixing methods are standard and invisible:
The standard method involves a picture frame that is made up of perimeter scaffolding with the wrap banner sitting about 150 mm inside the frame, fixed using 12 mm bungee cable (so the scaffold is visible).
The invisible method is more difficult but is generally thought to give a better appearance. The wrap banner is pulled completely smooth, placed over the outside of the picture frame scaffolding and clamped using clamp couplers/joins.
Typically, the scaffolding picture frame is installed before printing the wrap, so that an accurately measured template can be provided to the designers. This ensures that the wrap covers the scaffold completely, that it is taut enough and does not crease.
Building wraps can serve as a form of discreet advertising, in the same way as hoardings. However, they may require planning permission from the local authority.
A buttress is a structure built against another structure in order to strengthen or support it. Historically, they have been used to strengthen large walls or buildings such as churches, but they continue to be used in large modern structures such as retaining walls and dams.
Buttresses that are used to counteract, or retain, the lateral force of water or earth may be referred to as counterforts.
In their simplest form, buttresses may also be referred to as piers. See Piers for more information.
The term flying buttresses refers to an inclined beam carried on a half arch that projects from a structure to a pier which supports its weight and resists the horizontal thrust the of the structure.
A CAD layer is a component of a computer aided design (CAD) drawing file. Drawings can be organised by assigning objects to layers according to logical categories.
CAD drawings can quickly become visually complex, and difficult to structure as more objects are added. By assigning objects to different layers they can be collectively grouped, altered, moved and hidden from view as required. It can be helpful to think of layers as being the digital equivalent of clear plastic sheets that can be viewed and worked on separately, or combined to show multiple layers.
Objects can be associated by their function or location, related objects can be displayed or hidden in a single operation, and common properties such as line-type, colour, weight and so on can be enforced for each layer.
Layer properties managers can be used to organise layers. These lists the layers in the drawing, indicate current and visible layers and show layer properties. All new objects will automatically be placed on the current layer.
The default layer that exists in all drawings is Layer 0, although it is recommended that new layers are created rather than building a drawing solely on this layer. It can be useful to create a layer for drafting construction and reference geometry and other notes/calculations that will be kept hidden when viewing all the layers together and wont be printed. It is also generally recommended that hatches and fills are contained on the same layer, allowing them to be turned on or off in one action.
It is possible to: -
Turn off layers: Layers can be turned off to reduce the complexity of the drawing.
Freeze layers: Layers that do not need to be accessed can be frozen, which improves the performance of very large drawings.
Lock layers: This prevents changes to the objects on a layer being made accidentally. These layers are faded rather than hidden completely.
Set default properties: Default properties can be created, such as colour, linetype, lineweight, transparency, and so on.
When working on a project, it is important that everyone conforms to the same layer standards, as this enables the organisation of drawings to be more logical and consistent, as well as easier to share, collaborate and maintain over time.
A standard set of layers can be saved in a drawing template file as to be easily accessible. Standards such as AEC (UK) CAD Standard, BS EN ISO 13567-1:2017 or BS1192 might be used (now superseded by ISO 19650).
NB: BS 1192:2007+A2:2016 Collaborative production of architectural, engineering and construction information. Code of practice, (now replaced by BS EN ISO 19650) describes a layer as a ..container comprising selected entities, typically used to group for purposes of selective display, printing and management operations.
Capillary action is a phenomenon associated with surface tension, whereby liquids can travel horizontally or vertically (against the force of gravity) in small spaces within materials. It is sometimes referred to as capillary attraction, capillarity or wicking.
The movement is due to the surface tension that results when liquid or moisture is contained within very fine spaces or tubes (capillaries). Essentially, the liquid is attracted to the sides of the container; the smaller the space, the greater the attraction. Examples of capillarity include the action observed when a paper towel or blotting paper absorb water, and the way oil travels up a wick in oil lamps.
A canopy is an overhead roof structure that has open sides. Canopies are typically intended to provide shelter from the rain or sun, but may also be used for decorative purposes, or to give emphasis to a route or part of a building.
In classical architecture, canopy was a projecting hood or cover that was suspended over an altar, statue or niche, and was commonly found in churches throughout the Middle Ages.
The canopy evolved during the Renaissance to become a baldachin, a fixed structure supported on pillars that was common in baroque architecture.
Today,canopies may be independent of other structures, or may projects out from a structure such as a building, typically providing shelter at an entrance. It may be supported by the building it is attached to, and / or ground mountings cables, stanchions or upright support posts.
A cantilever is a beam supported only at one end, with load carried over the overhanging. This is in contrast to a simply-supported beam, which is supported at both ends.
Cantilevers provide a clear space underneath the beam without any supporting columns or bracing.
Cantilevers became a popular structural form with the introduction of steel and reinforced concrete. They are used extensively in building construction, notably in:
Cantilever bridges. - Overhanging elements and projections.
Overhanging elements and projections. - Balconies, such as at Frank Lloyd Wrights Falling water.
Balconies, such as at Frank Lloyd Wrights Falling water.
Machinery and plant such as cranes. - Overhanging roofs such as stadium roofs, and shelters.
Overhanging roofs such as stadium roofs, and shelters.
Shelving. - Furniture.
Furniture. - Cantilever construction can be used in bridge building for crossing large spans. A simple cantilever span is constructed from two cantilever arms extending from opposite sides, and meeting in the middle. A common variation of this is the suspended span where the cantilever arms support a central truss bridge resting on the ends of the cantilever arms. A classic example of the cantilever bridge is the Forth Railway Bridge in Scotland which has three cantilevers with two connecting suspended spans.
Cantilever construction can be used in bridge building for crossing large spans. A simple cantilever span is constructed from two cantilever arms extending from opposite sides, and meeting in the middle. A common variation of this is the suspended span where the cantilever arms support a central truss bridge resting on the ends of the cantilever arms. A classic example of the cantilever bridge is the Forth Railway Bridge in Scotland which has three cantilevers with two connecting suspended spans.
Cantilever cranes (otherwise known as 'hammerhead crane') are hoisting cranes with a swing or fixed cantilever along which a hoisting trolley moves. They are often used in shipyards and during the construction of tall buildings.
Carbon nanotubes (CNTs) are allotropes of carbon having a cylindrical nanostructure.
Carbon Nanotubes are a tube-shaped material made up of carbon molecules, having a diameter of approximately a nanometer (one-billionth of a meter or one ten-thousandth of the thickness of a human hair). Carbon nanotubes has many different structures, depending on length, thickness and type of helicity (projection of the spin on direction of momentum), and number of layers.
All carbon nanotubes are made up of similar graphite sheet. However, the electrical characteristics of carbon nanotubes (acting as metals or semiconductor) depends on the structure they exhibit. Carbon nanotubes exhibit excellent mechanical strength, comparable to graphite. They can replace other materials in wide range of application such as; consumer goods, electrical and electronics, energy, healthcare, automobile, aerospace, and defense sectors. Other applications include;, conductive plastics, flat-panel displays, gas storage, batteries with improved lifetime, technical textiles, antifouling paint and micro- and nano-electronics.
Carbon nanotube materials can be categorised on the bases of structure and number of layers; single-wall nanotubes (SWNT) (having diameter close to 1nm), multi-wall nanotubes (MWNT) (diameter ranging between 5 nm to 50 nm) and double-wall nanotubes (DWNT) (sub-segment of multi-wall nanotubes). Multi-wall nanotube has the major market share in the global carbon nanotube market, followed by single-wall nanotubes.
Casement is a term usually associated with windows and denotes a window with a glazed 'sash' that is hinged at the sides (side hung), or at the top (top hung) or at the bottom (bottom hung). The parts that open are therefore separate from the frame and are referred to as hinged sashes. This is in contrast to what traditionally would have been called sliding sash windows, where opening is achieved by a vertically sliding sash that moves within the frame.
Casement windows were used before the advent of the sliding sash window which only appeared in the early Georgian period. Before this, casement windows (often with latticed lights) were the predominant window type.
Casement windows usually open from the inside outwards and, depending on the design, can offer full opening for maximum ventilation, as well as allowing a person to lean out. This can also free-up space inside (compared to opening inwards) and may better direct air inwards for ventilation. Typically, if the hinges are on the right of the sash, the locking mechanism will necessarily be on the left, and vice-versa.
In recent years, casement windows in the UK have become more popular than sliding sash windows because they are less complex (no need for hidden cords, pulleys and weights), more economical, have more compact frames, close more tightly, and are easier to manufacture and assemble. Their popularity has spread in part thanks to the marketing activities of replacement window companies which typically replace sliding sash windows with casements.
Configuration - The frame of a casement window may be divided vertically (with mullions) or horizontally (with transoms) or feature both. The sash or sashes will fit within the frame and be either top-, side or bottom-hinged. Side-hung sashes are usually fitted on butt hinges or easy-clean hinges which allow access to the outside of the glass from the inside. It is quite common to see a central mullion dividing the window frame in two: one half will feature a side-hung sash while the other will have a transom to create a smaller top-hung sash useful for trickle ventilation (see photo).
The frame of a casement window may be divided vertically (with mullions) or horizontally (with transoms) or feature both. The sash or sashes will fit within the frame and be either top-, side or bottom-hinged. Side-hung sashes are usually fitted on butt hinges or easy-clean hinges which allow access to the outside of the glass from the inside. It is quite common to see a central mullion dividing the window frame in two: one half will feature a side-hung sash while the other will have a transom to create a smaller top-hung sash useful for trickle ventilation (see photo).
Top-hung sashes of casement windows are usually secured with a stay while side-hung are secured with a casement stay on the bottom stile which has various adjustable positions and acts to lock the window in the closed position.
Modern sliding sash windows will typically also act as a casement when required so that the glazed part can open inwards for cleaning from the inside.
Casement - Casement window pixabay 640.jpg
Casement window pixabay 640.jpg - Contents
Contents - [hide]
[hide] - 1 Introduction
1 Introduction - 2 Configuration
2 Configuration - 3 Materials
3 Materials - 4 Doors
4 Doors - 5 Related articles on Designing Buildings Wiki
5 Related articles on Designing Buildings Wiki - Introduction
Introduction - Casement is a term usually associated with windows and denotes a window with a glazed 'sash' that is hinged at the sides (side hung), or at the top (top hung) or at the bottom (bottom hung). The parts that open are therefore separate from the frame and are referred to as hinged sashes. This is in contrast to what traditionally would have been called sliding sash windows, where opening is achieved by a vertically sliding sash that moves within the frame.
Casement is a term usually associated with windows and denotes a window with a glazed 'sash' that is hinged at the sides (side hung), or at the top (top hung) or at the bottom (bottom hung). The parts that open are therefore separate from the frame and are referred to as hinged sashes. This is in contrast to what traditionally would have been called sliding sash windows, where opening is achieved by a vertically sliding sash that moves within the frame.
Casement windows were used before the advent of the sliding sash window which only appeared in the early Georgian period. Before this, casement windows (often with latticed lights) were the predominant window type.
Casement windows usually open from the inside outwards and, depending on the design, can offer full opening for maximum ventilation, as well as allowing a person to lean out. This can also free-up space inside (compared to opening inwards) and may better direct air inwards for ventilation. Typically, if the hinges are on the right of the sash, the locking mechanism will necessarily be on the left, and vice-versa.
In recent years, casement windows in the UK have become more popular than sliding sash windows because they are less complex (no need for hidden cords, pulleys and weights), more economical, have more compact frames, close more tightly, and are easier to manufacture and assemble. Their popularity has spread in part thanks to the marketing activities of replacement window companies which typically replace sliding sash windows with casements.
Configuration - The frame of a casement window may be divided vertically (with mullions) or horizontally (with transoms) or feature both. The sash or sashes will fit within the frame and be either top-, side or bottom-hinged. Side-hung sashes are usually fitted on butt hinges or easy-clean hinges which allow access to the outside of the glass from the inside. It is quite common to see a central mullion dividing the window frame in two: one half will feature a side-hung sash while the other will have a transom to create a smaller top-hung sash useful for trickle ventilation (see photo).
The frame of a casement window may be divided vertically (with mullions) or horizontally (with transoms) or feature both. The sash or sashes will fit within the frame and be either top-, side or bottom-hinged. Side-hung sashes are usually fitted on butt hinges or easy-clean hinges which allow access to the outside of the glass from the inside. It is quite common to see a central mullion dividing the window frame in two: one half will feature a side-hung sash while the other will have a transom to create a smaller top-hung sash useful for trickle ventilation (see photo).
Top-hung sashes of casement windows are usually secured with a stay while side-hung are secured with a casement stay on the bottom stile which has various adjustable positions and acts to lock the window in the closed position.
Modern sliding sash windows will typically also act as a casement when required so that the glazed part can open inwards for cleaning from the inside.
Casement windows are available in a wide choice of materials and styles and usually come as single- double- or triple-glazed. They are available in timber, PVC, aluminium, steel and composite.
Traditional types such as the Crittall window were made of galvanised mild steel and were popular for apartment blocks. Single-glazed, they often had a 1930s appearance and had a slimmer framework than timber windows. Being made of steel, they were usually very strong but frequently suffered from cold-bridging while the single-glazing resulted more often than not in condensation in winter, especially if a room was poorly ventilated.
Contemporary aluminium casement windows, typically polyester powder-coated, are much-improved when compared to their earlier counterparts of the 1970s and 1980s and are available as replacements for old wooden or traditional windows.
Recent years have seen the introduction of composite materials which combine wood fibre, mostly reclaimed, with thermoplastic polymer. The resulting composite is claimed to be twice as strong as PVC and offers a thermal transmission that is claimed to be superior to aluminium.
PVC casement windows tend to have a chunkier frame and sashes. When viewed from the outside, it is usually possible to discern the opening sash due to its increased thickness (compared to the frame) which can look unsightly in some configurations. However, modern design and manufacturing techniques produce windows that are very often superior both thermally and acoustically when compared to traditional types and can not easily be disitnguished from painted timber windows.
Casement is a term that is also applied to doors.
A casement door is similar in concept to a casement window: a hinged single sash (opening door leaf within a frame) or a dual sash to result in what is usually referred to as a French door. French doors are casement doors which are semi- or fully-glazed and used widely throughout Europe as a means to connect the inside with the outside, often a patio, garden, grounds, deck or balcony.
Casement doors are available in the same materials used for casement windows, i.e wood, PVC, aluminium etc.
A casing is an enclosure or housing which contains another material or component(s) and functions as a case. This is normally to protect the contents of the casing from exposure to, or damage by; heat, water, knocks from handling or human interference. It may also conceal the components if they are of an unsightly nature and/or do nor normally need to be accessed.
Casings can be temporary or permanent. A fuse box is housed in a permanent casing, as is pipework that is boxed-in for purposes of concealment. The delivery of a sensitive item to a construction site such as a boiler or chiller is likely to be in a temporary casing for protection (as opposed to a cardboard box) which is discarded (or recycled) as soon as delivery to site has been completed. The outer casing of a mobile phone can be permanent or temporary.
Casings can be made from various materials, including:
Cardboard. - Plastic.
Plastic. - Metal.
Metal. - Timber.
Timber. - Growing environmental awareness has seen casings being made from more sustainable materials that can be easily recycled, such as cardboard and wood products, as well as biodegradable and compostable materials.
Growing environmental awareness has seen casings being made from more sustainable materials that can be easily recycled, such as cardboard and wood products, as well as biodegradable and compostable materials.
A cassette is typically a flat case or cartridge that can be easily installed or removed. It is derived from the Old North French word casse, meaning box.
In the construction industry the word cassette refers to components of building services systems such as chilled water cassettes, or to modular construction components such as facade cassette panels, floor cassettes, wall cassettes, roof cassettes and so on, which may include timber or metal frame, cladding, insulation and so on in a single unit. Typically cassettes are prefabricated in a factory setting and then installed quickly on site, reducing the need for working at height. They may also be removable without being damaged so they can be re-used.
The term 'cast iron' refers to a range of iron-carbon alloys, with a carbon content that is typically between 2 and 4%. During the Industrial Revolution, before the widespread development of the steel industry, cast iron was commonly used in a wide range of architectural applications because of to its relative affordability.
Cast iron is manufactured by re-melting pig iron along with quantities of limestone, silicon and carbon (and sometimes scrap steel). Traditionally, cast iron is melted in a blast furnace known as a cupola, but it can also melted in electric induction furnaces or arc furnaces. The molten cast iron is then poured into a holding furnace or ladle ready for casting (that is, being poured into a mould, and allowed to cool).
The advantages of using cast iron derive from its relatively low melting temperature, which increases its usability, and its good compression strength. However, it is weak in tension and bending, and will fracture before it bends or distorts. It also loses strength and stiffness when subjected to high heat.
In comparison with wrought iron or steel, cast iron is non-malleable, hard and brittle.
Cast-in-place concrete, also known as poured-in-place, is a concreting technique which is undertaken in situ or in the concrete components finished position. Cast-in-place concrete is the preferred choice for concrete slabs and foundations, as well as components such as beams, columns, walls, roofs, and so on.
The concrete is typically transported to site in an unhardened state, often using a ready mixed concrete truck. A chute extends from the back of the truck to place the concrete either in the required location or into a dumper or pump.
An alternative concreting technique is precast concrete which is prepared, cast and cured off-site, usually in a controlled factory environment, using reusable moulds. For more information, see Precast concrete.
While cast-in-place concrete can allow for greater flexibility and adaptability, it can be difficult to control the mix particularly if weather conditions are not favourable. Cast-in-place concrete will also require a strength test and time for curing, which makes it slower to construct than precast concrete. However, there are fewer joints in the structural system not as much handling equipment is required.
Caulk is filler material commonly used by decorators. Most caulks are more rigid than sealants, but more flexible than other fillers when they dry and can be used where movement or leakage can occur - as long as significant expansion or contraction is not anticipated.
Historically, caulk was made from fibrous materials that could be driven between boards, pipes and so on to make them waterproof. Rope caulks are still available and are primarily used to reduce drafts, and sound transmission, especially around windows.
Modern caulk is also waterproof. It is typically made from acrylics, vinyl or silicone. These materials dry quickly and remain relatively flexible. It can be used to close small gaps and crevices. It prevents air, insects, rodents and dust from compromising the integrity of seals, spaces and structures.
Acrylic caulk can be painted after it has dried completely. However, painted caulk can crack if it is applied in temperatures lower than four degrees Celsius. Silicone caulk cannot be painted.
Caulk is generally sold in cartridges that can be inserted into caulking guns. This technique helps to control the application process. If spills and smears occur during the process, they can be cleaned up with water rather than solvents.
It is possible to caulk over old acrylic caulk, unless the old caulk is oily, dirty or has deteriorated significantly (in which case, the new caulk will not adhere). Caulk should not be applied over old caulk that is wet or has mould or mildew.
Category 5 cable (CAT5 or Cat 5) is the fifth generation of standard, twisted-pair cable used for carrying signals, typically ethernet. It provides performance of up to 100 MHz and is commonly used for wired local area networks (LANs) and can carry data, telephone communications and video. It is possible to carry multiple signals on a single cable.
The standard for CAT 5 was defined by the Electronic Industries Association (EIA) and the Telecommunications Industry Association (TIA).
CAT5 cable usually, although not always, contains four twisted pairs of copper wire. These can be solid or stranded. Solid can be used over longer runs and is best suited to permanent wiring whereas stranded is more flexible and so is better able to withstand bending commonly encountered in temporary uses.
An enhanced specification CAT5e provides improved crosstalk and system noise characteristics. In addition newer, higher performance standards have been developed such as CAT6, CAT6a and CAT7, however CAT5 and CAT5e remain popular as they are relatively economical and provide a reasonably good standard of performance.
Ethernet is a standard for the technologies that make up a wired local area network (LAN). It was first developed in the 1970s by Robert Metcalfe at Xerox and went on to be developed by Xerox, DEC, and Intel. It was standardised by the Institute of Electrical and Electronic Engineers (IEEE) as IEEE 802.3 in 1983.
Ethernet was originally conceived as a way of enabling computers to communicate over a shared cable. Ethernet originally used coaxial cable, but now commonly uses twisted-pair copper cable such as CAT5 or fibre optic cable.
The simplest Ethernet connects a number of devices on a single cable. Streams of data that are transmitted between devices are divided into frames with a source and destination address. If more than one device is transmitting at the same time, and frames collide and are corrupted, then they are re-transmitted. More complex variations allow devices to run with much reduced corruption, and full duplex modes allow devices to communicate simultaneously without collision.
Ethernet is now the most widely used standard for local area networks (LAN). Local area networks are networks used to connect a number of devices together that are located within a relatively small area, typically within a single building. This is as opposed to wide area networks (WAN) which are used to connect devices on a dedicated line across a large distance, such as across a city.
Chipboard (sometimes called particle board or low-density fibreboard (LDF)) is a versatile, material that is relatively cheap and can be used to make furniture (including carcasses for kitchen units), other cabinet applications, floor decking, shelving and general building work. Although the material was originally formulated in late 19th century Germany, it was not until the Second World War that it was produced commercially.
Chipboard comprises small chips and flakes of softwood that are impregnated with adhesive (usually amino formaldehyde-, urea formaldehyde-, or urea melamine-based) and subjected to high temperature (up to 220C) and pressure (2-4MP). When cooled, the boards are cut and sanded, sold either as plain board or faced with laminate. They can be supplied in various densities.
Displaying greater uniformity, chipboard is a more economical, denser and more stable material than solid timber under a variety of conditions, in particular tolerating the dryness induced by central heating systems. However, it can be affected by atmospheric changes and, when damp, is likely to swell. It can also discolour when it absorbs moisture. If moisture exposure is anticipated, the chipboard is usually treated with a sealer or painted. Chipboard is not usually used for external applications.
Although not as strong as solid timber, chipboard can be used as an adequate substitute for most purposes. However, as there are numerous grades of chipboard, it is important to ensure the grade is matched to the application. This applies particularly to flooring.
Grades of chipboard include: -
Moisture-resistant. - Sanded smooth on both sides.
Sanded smooth on both sides. - Ready-faced with timber or melamine veneers.
Ready-faced with timber or melamine veneers. - Ordinary chipboard can also be filled, primed and painted. As such, it forms a good substrate for veneers and other facings.
Ordinary chipboard can also be filled, primed and painted. As such, it forms a good substrate for veneers and other facings.
When specified for flooring, it is important to ensure the board has the requisite strength, usually described by manufacturers as flooring grade in thickness of 18-19mm or 21-22mm, and in sheet sizes usually of 8ft x 4ft (2.4m x 1.2m). Flooring boards can be supplied with tongue and groove edges on all sides to ensure a more monolithic, stronger deck.
Clunch is a form of soft, chalky limestone rock that closely resembles chalk and shares many of its characteristics, but with lower density. It is used mainly in eastern England and Normandy.
The term is also generically applied to soft, inferior building stone that is used in place of stronger, more desirable material.
In its freshly quarried state, clunch is soft and holds water, which makes it easier to cut. Once dry, it hardens and becomes more difficult to cut.
Clunch was used extensively in medieval times as a building material. It was often used for chimneys, property boundary walls and small agricultural buildings.
It was not suitable for large scale use, since it would easily erode when exposed to chemicals or severe weather. Structures made from clunch had to be protected with paint, cement or stucco and could then be finished with a lime wash.
However, even when the surfaces were covered, clunch was not especially durable and could even be damaged by frost. Despite this, it was often used in certain parts of the country, since it was inexpensive and widely available.
Construction Operations Building Information Exchange (COBie) is a non-proprietary data format for the publication of a subset of building information models (BIM) focused on delivering asset data rather than geometric information. It is formally defined as a subset of the Industry Foundation Classes (IFC - the international standard for sharing and exchanging BIM data across different software applications), but can also be conveyed using worksheets or relational databases.
COBie was devised by William East of the United States Army Corps of Engineers, who authored a pilot standard in 2007 to improve the process of handing over information to building owners, occupiers and operators enabling them to manage their asset more efficiently. In 2008 it became COBie when it was revised to comply with international standards for data and classification.
COBie helps capture and record important project data at the point of origin, including equipment lists, product data sheets, warranties, spare parts lists, preventive maintenance schedules and so on. This information is essential to support operations, maintenance and asset management once the built asset is in service.
COBie does not increase the need for information, it simply structures it in a more accessible format, so that it is easier to use and re-purpose. The format is intended to be easy to manage by any organisation, irrespective of size and IT capability. Its simplicity means that all tiers of the supply chain should be able to contribute to the data set, even if just by entering it directly into the spreadsheet. The format also 'insulates' the client from unnecessary complexity, technology changes, interoperability problems and proprietary software issues.
In May 2011 the UK government published the Government Construction Strategy, announcing the government's intention to require Level 2 BIM (collaborative 3D BIM with all project and asset information, documentation and data being electronic) on its projects by 2016. The required submissions of BIM information for Level 2 are in the COBie format. These submissions, or 'data drops' are required at key milestones through the development of projects to ensure they are properly validated and controlled, enabling the client to check the available data in terms of technical compliance, compliance with the brief, cost / price, and so on.
Generally, data drops are aligned to project stages, and the information required reflects the level of development that the project should have reached by that stage. As it develops, the COBie file may contain data from consultants, the contractor, sub-contractors and suppliers, and even the client. Ultimately the data will provide information for the efficient operation and management of the facility.
COBie consists of multiple sheets documenting attributes of the facility, its systems and assets and details of their product types, warranties, maintenance requirements and so on. As the project develops so additional attributes, issues and documentation can be associated to specific items.
The term combustibility refers to the tendency of a substance to burn as a result of fire or chemical reaction. It is can be expressed as a property that is a measure of how easily a substance will ignite or burn, an important consideration when materials are being used or stored for construction purposes.
The term flammable may be used to describe substances that ignite more easily, whilst substances that are harder to ignite or that burn less intensely may be referred to as combustible. For more information see: Flammable.
Less combustible materials may be described as 'materials of limited combustibility'. Approved document B of the building regulations defines limited combustibility as: 'a material performance specification that includes non-combustible materials, and for which the relevant test criteria are set out in Appendix A, paragraph 9.'
Approved document J, Combustion appliances and fuel storage systems defines non-combustible materials as:
the highest level of reaction to fire performance. Non-combustible materials include:
Any material which when tested to BS 476-11:1982 (2007) does not flame nor cause any rise in temperature on either the centre (specimen) or furnace thermocouples.
Products classified as non-combustible in tests following the procedures in BS 476-4:1970 (2007).
Any material classified as class A1 in accordance with BS EN 13501-1:2002 Fire classification of construction products and building elements. Classification using data from reaction to fire tests.
Following the Grenfell Tower Fire, a decision was taken to ban combustible materials in the cladding for buildings over 18m in height. The following change to approved document 7 came into force on 21 December 2018.
The Building Regulations restrict the use of combustible materials in the external walls of certain buildings over 18m in height. Refer to regulation 7(2) of the Building Regulations and to Approved Document B: volume 2, part B4 for details.
The issue was raised again in November 2019 following a fire at The Cube in Bolton. In this case HPL cladding was used, and the building was less than 18m in height, resulting in calls for the ban on combustible cladding materials to be extended. For more information see: The Cube.
On 27th November 2019, after a challenge to the consultation process that introduced the ban, the High Court ruled that the consultation had been inadequate in respect of the inclusion of products intended to reduce heat gain within a building (for example, blinds, shutters and awnings) within the ban. As a result the Court quashed one part of the 2018 regulations which had included within the ban a device for reducing heat gain within a building by deflecting sunlight which is attached to an external wall. The practical effect of the Court judgment is that the regulations now exist as if that section of the regulations had never been included in the ban. Ref https://www.gov.uk/government/publications/building-amendment-regulations-2018-circular-032019
In January 2020, the government launched a review of the ban on the use of combustible materials in the external walls of buildings over 18m that was introduced in 2018.
Computer numerical control (CNC) is the digital manipulation of machines such as drills, lathes and other machine tools by computers and circuitry. Also known as numerical control or computational numerical control, the process comprises a series of numerical values generated by a computer; each of which is assigned to a desired tool or control position to enable the machining of a blank piece of material to precise specifications without requiring a manual operator.
The process dateso back to the first CNC machines built in the 1950s and 60s which relied on punched tape (or perforated paper tape) to communicate the tool position that was controlled by a motor. The process has since been refined and improved by analogue and digital computers.
Under CNC, every object to be manufactured is allocated a G-code (an international standard language) that is stored in the machine and executed by a microcomputer (machine control unit or MCU) attached to the machine. The G-code is a set of instructions such as the positioning or speed of the tools components that the machine will follow to create or part-create the item in question. Typically, this allows the automation of machine tools such as lathes, mills, routers, lasers and grinders.
In sophisticated manufacturing operations, G-codes are typically derived from the automatic translation of engineers CAD drawings into a sequential programme of machine control instructions which are then implemented. A less complex method is writing part-programmes using high-level, part-programming languages.
CNC does not rely on conventional control by cranks, cams and gears. Instead, it allows desired feed rates and cuts to be dialled in, thereby providing precise, repeatable machine movements that can be optimised for speed, feed and machine cycles.
CNC machines give flexibility of manufacture, especially when variable and complex part geometries are required. Parts can be produced in batches of just a few to several thousand.
Automated blinds (or smart blinds) are window treatments that are operated by a motor situated within the roller mechanism. The motors can be wired, battery or solar powered, and the blinds can be adjusted by switch or remote control. They can also be wired directly into an integrated building automation system in large scale applications or controlled by systems such as Amazon Alexa or Google Home voice controls in small scale applications.
Automated blinds can be used in conjunction with daylight systems designed to optimise natural lighting. The automated blinds can be programmed to work with sensors that measure natural lighting levels so the blinds are automatically repositioned as sunlight levels increase or decrease. Automated blinds can coordinate with automated lighting systems that respond to sunlight levels to create an integrated and efficient approach.
The blinds can be programmed to respond to natural temperature fluctuations that occur when excessive levels of sunlight create unwanted solar gain or an increased demand for cooling. When specific temperatures are reached, the blinds can automatically respond in a manner that supports heating and cooling targets. They can also be raised automatically when interior temperatures are low so that warmth from the sun can be allowed to enter.
These capabilities can be particularly valuable in spaces with tall windows, windows positioned well above the floor, or south facing windows.
A conductor is a material that conducts heat or electricity or both.
Conduction is the process whereby heat or electricity diffuses, or move across a material as a result of a difference between its parts. Conductivity is the rate at which conduction occurs.
Thermal conductance - A conductor is a material with a high thermal conductivity, i.e. it allows heat to pass freely through it when there is a temperature difference between it and the ambient environment or between it and another substance with which it is in contact.
A conductor is a material with a high thermal conductivity, i.e. it allows heat to pass freely through it when there is a temperature difference between it and the ambient environment or between it and another substance with which it is in contact.
Materials with high thermal conductivity tend to be poor insulators (e.g metals) as opposed to materials with low thermal conductivities that tend to be good insulators (e.g polystyrene).
In building construction, a material with a low thermal conductivity and hence a good insulator can be used to improve the thermal performance building elements such as wall and roof constructions. Polystyrene, polyurethane and mineral fibre are all excellent insulators that provide good resistance to the passage of heat. They are therefore used to help constructions attain (or exceed) the thermal performance (U-values) required by building regulations. For more information see: Insulation.
All materials conduct heat to a greater or lesser extent. If this were not the case, situations such as cold bridging would not occur. Cold bridging occurs when heat inside a building finds a pathway to the outside (when it is colder) through the layers of construction (and the air spaces) that are in contact with each other. This occurs because even poor heat conductors such as concrete and masonry will allow some heat to pass through when there is a temperature difference across them. Preventing cold bridging requires breaking this path of heat transfer using a material of low thermal conductivity, i.e. an insulator such as polystyrene, but it also means ensuring there are no air spaces on critical paths. For more information see: Cold bridge.
The internal to external thermal transmittance rate of a construction assembly is known as a U-value (i.e. the number of Watts transmitted through 1m2 of construction per degree Kelvin difference in temperature between the air on each side of the construction). For more information see: U Value.
See also Thermal conduction. -
Electrical conductance - In relation to electricity, a conductor is a material which offers low resistance to the flow of electricity (the flow of electrons or electrically-charged particles) and is therefore able to conduct an electric current. Electrical conductivity (also known as specific conductance) is the rate at which a material conducts electricity. It is the reciprocal to electrical resistivity, the measure of how much a material resists the flow of an electrical current.
In relation to electricity, a conductor is a material which offers low resistance to the flow of electricity (the flow of electrons or electrically-charged particles) and is therefore able to conduct an electric current. Electrical conductivity (also known as specific conductance) is the rate at which a material conducts electricity. It is the reciprocal to electrical resistivity, the measure of how much a material resists the flow of an electrical current.
Most metals and plasma have high electrical conductivity, but to different extents. Silver is regarded as the best electrical conductor; copper, gold, aluminium, zinc, nickel and brass follow. Copper is an excellent conductor and is used widely in wiring systems; aluminium is better than iron. Lead is a poor conductor compared to the aforementioned.
Electrical conductivity occurs in various degrees in these metals due to the ease with which electrons in the outer shell of an atom (valence or free electrons) can be separated and are free to travel around, passing on an electric charge. Temperature also plays a part: when the temperature of metallic conductors is decreased, the electrical conductivity increases.
Other materials such as dry wood, glass, paper, rubber, diamond, air and most plastics are poor electrical conductors and are therefore said to be non-conductors or insulators.
Semi-conductors such as silicon and germanium can also conduct electricity but are not particularly efficient at doing so. They must therefore be heated or doped with other elements, after which they can become extremely efficient electrical conductors.
An autonomous vehicle (AV) is a self-driving vehicle which requires little or no human direction, can sense its environment, typically navigates by satellite and detects objects in its path that it must avoid.
AVs are not just cars: they can also be trains, ships, trucks, drones, tractors, lunar vehicles and so on. They are typically equipped with computers, software and sensors which gather information about the external environment, and are connected to satellites.
For road vehicles, there are two main levels of automation:
Fully autonomous, where the AV can complete journeys safely without a driver in normally-encountered traffic conditions, and
Highly automated, where the vehicle can operate in driverless mode but must have a driver on-board to take control if necessary.
Todays cars can commonly offer assisted driving, with automatic braking, cameras to monitor hazards, parking assistance and alarms to alert drivers when they have strayed from designated lanes.
When full autonomy occurs, autonomous cars may:
Drive themselves from door-to-door without a driver, including in city and motorway conditions.
Communicate through the Internet of Things with each other and the road infrastructure and so make decisions about optimal routes, internal temperature etc.
Have no options for drivers to take control of vehicles.
One of the biggest questions around vehicle autonomy is, given the driver is not in control, who will be liable in the event of an accident? If the software goes wrong should the vehicle provider, software developer or the vehicle manufacturer be liable? Questions such as these are still being debated hotly by the industry.
And are current drivers competent enough to be in control of highly automated vehicles (HAVs)? A report by the House of Lords Science & Technology committee suggested that drivers with existing licences should be required to take a special driving test to ensure they can take back control in an autonomous car.
Research showed that driver responses in AV conditions are slower than when they are in full control of a vehicle, taking on average six times longer to respond to emergency braking situations. This could be, the report suggested, because drivers can become complacent under autonomous conditions.
AVs will potentially transform cities due to safer roads, fewer accidents, less congestion and smoother traffic flow, with extensive freeing-up of conventional parking space. They could also bring about changes in car ownership patterns and change the urban landscape.
The term conglomerate may refer to a rock that contains gravel or cobble size material within a finer grained matrix.
Define a conglomerate as: A sedimentary rock, a significant proportion of which is composed of rounded pebbles and boulders, greater than 2 mm in diameter, set in a finer-grained groundmass.
It may also refer a parent company that has subsidiary companies trading in unrelated markets. Conglomerates have a legal identity separate from the subsidiaries, but are generally liable for the debts of subsidiary companies.
Concrete superplasticizers (or concrete superplasticisers) play a vital role in improving the quality and reducing the cost of construction. Superplasticizers are particularly suited to the manufacture high strength concrete for construction. Ready-mix concrete, precast concrete, shotcrete and high-performance concrete are the major applicants of superplasticizers.
They are chemical admixtures that have water-reduction capabilities that range from 5.0% to 40.0% in concrete mixes. They are usually classified according to the raw material used, such as naphthalene, melamine, lignosulfonates, and polycarboxylic acids.
With investment and support from regional governments for construction, the demand for superplasticizers is about to grow aggressively.
The global concrete superplasticizers (CSP) market is expected to reach USD 4.77 Billion by 2020, growing at a CAGR of 8.2% between 2015 and 2020. This growth is fuelled by high demand from emerging economies and because of precieved ecological benefits.
The concrete superplasticizers market is segmented into five types:
Sulfonated naphthalene formaldehydes (SNF). - Sulfonated melamine formaldehydes (SMF).
Sulfonated melamine formaldehydes (SMF). - Modified lignosulfonates (MLS).
Modified lignosulfonates (MLS). - Polycarboxylic acids (PC).
Polycarboxylic acids (PC). - Others.
Others. - The use of these superplasticizers increases the efficiency of their applications. Individual superplasticizers have application-specific demands that are differentiated by placement, cost, and efficiency:
The use of these superplasticizers increases the efficiency of their applications. Individual superplasticizers have application-specific demands that are differentiated by placement, cost, and efficiency:
Naphthalene superplasticizers are useful in ready-mix concrete applications for the construction of buildings and bridges.
Polycarboxylic acids are the latest and expensive superplasticizer, used in high-end constructions such as airports and government infrastructure.
Polycarboxylates are third generation superplasticizers that have revolutionised the market with their ability to reduce the water to cement ratio by 40.0% even at low dosages. Compared to other superplasticizers, polycarboxylates at a dosage rate of 0.15% to 0.3% can achieve 30.0% to 40.0% water reduction. They are also suitable in hot weather conditions and can be transported to long distances. They can be used in all applications, in particular in high-strength and self-compacting concrete applications
The Middle East & Africa and Asia-Pacific accounted for more than 72.7% of the concrete superplasticizers market in 2015
Middle East & Africa is the second largest consumer of superplasticizers, globally. The Asia-Pacific region is the largest, with major developments in China and India. The Middle East & Africa and Asia-Pacific are expected to compete with each other to dominate the market by 2020, with advanced technological developments in superplasticizers for end-users. Asia-Pacific is expected to remain the major market till 2020, with high investment in construction due to growing population.
Major players such as Arkema SA (France), BASF SE (Germany), Kao Corporation (Japan), Sika AG (Switzerland), and W.R. Grace & Co. (U.S.) have adopted development strategies such as expansion, acquisitions, and product development to achieve growth in the market.
Quality control is very important. Pre-material testing takes place at manufacturing laboratories before its used. Choosing a suitable superplasticizers is the most important task for any application.
A conservatory is a structure typically attached to a building such as a house consisting of low level brick walls with framed glazing above. In the UK, a space is considered to be a conservatory if it has glazing for at least 50% of its side wall area and at least 75% of its roof.
Traditionally, European cities built conservatories in the 19th century for horticultural purposes and for entertaining, although as far back as the 16th century wealthy landowners had built similar structures to cultivate citrus fruits. With the onset of the Second World War, there was a halt in the construction of conservatories in Britain, and they were only revived again in the 1970s. Today, conservatories are a popular way of maximizing the size of existing properties as the cost of moving to a new property has increased.
The term banister (or occasionally 'bannister') refers to the assembly of uprights and handrail at the side of a staircase.
The uprights may be referred to as balusters, and collectively, along with the handrail may sometimes be referred to as a balustrade, particularly if they are ornamental.
A banister can act as both guarding and handrail.
A handrail is ..a rail, at hand height or a little higher, for people to hold for support.
Guarding is a barrier that denies pedestrians or vehicles access to another area.
In buildings that might be used by children under 5, guarding should be designed so that a 100 mm sphere cannot pass through, it should prevent children being held fast and should be difficult to climb.
A finial is a small, ornamental, termination piece that can be found at the top of some architectural features such as gables, pinnacles, newel posts and gate posts, as well as on the top of parts of some pieces of furniture, at the end of curtain poles and so on.
They are typically spherical in shape, but may be very ornamented, or even sculptural.
The word 'finial' is derived from the Latin finis meaning end.
It may also be used to refer to a lightning condutor.
A crocket is an architectural element commonly used for ornamental purposes to decorate column capitals and cornices, as well as the inclined edges of spires, finials, pinnacles, and gables.
Crockets are typically stylised carvings of curled leaves, buds or flowers arranged in rows projecting from structural elements in the form of a ball, or hook. They are often found on gothic buildings and medieval cathedrals. They can also be found as an ornamental element on Gothic furniture and metalwork.
They first appeared in the medieval architecture of the late-12th century, and took the form of a ball-like bud with a spiral outline. This form developed into open leaves by the late Gothic period. By the 15th century, crockets had evolved into richly involuted forms.
In the classical architecture of Ancient Greece and Rome, a frieze is a long and narrow sculptural band that runs along the middle of an entablature, used for decorative purposes. It sits on top of the column capitals, in between the architrave on the lowest level and the cornice at the top.
In buildings using the Doric architectural order, the frieze is usually consists of alternate triglyphs (projecting rectangular blocks with three vertical channels), and metopes (spaces). In buildings using the Ionic, Corinthian or Composite orders, the frieze is usually ornamented with relief figures. Friezes seen on Roman buildings are usually decorated with plant motifs. Late Roman and many Renaissance structures feature a pulvinated frieze, in which the friezes profile is a convex curve.
In the Doric order, triglyphs often appear regularly-spaced on the frieze. These are rectangular details, representative of the beams used to post and beam construction. The spaces between triglyphs are called metopes.
The most famous example of a frieze is that carved on the outer wall of the Parthenon temple in Athens, Greece, which is a representation of a ritual festival procession.
In interior design, a frieze can also refer to any long, narrow, horizontal panel or band used for decorative purposes on the walls of a room.
Gargoyles are carvings of grotesque figures, faces or creatures perching along the roofs and battlements of buildings and projecting from roof gutters. The gargoyle is one of the most recognisable characteristics of Gothic architecture.
The etymology of the word derives from the French gargouille meaning throat. The precise purpose of gargoyles was to act as a spout to convey water from the upper part of a building or roof gutter and away from the side of walls or foundations, thereby helping to prevent water from causing damage to masonry and mortar. The gargoyle would have a trough carved into its back down which rainwater would run and exit through the characteristically large open mouth.
While common parlance uses the term gargoyle to mean any fantastical or mythical figure used for ornamental purposes, the strict architectural usage only applies to those serving a waterspout function.
Mouldings, also known as covings, are decorative strips used to cover transitions between surfaces in aesthetically pleasing ways. In classical architecture they are commonly found on columns and entablatures. Traditionally, mouldings were carved in marble or stone, but today, they are also commonly made from timber, plaster and plastics. Mouldings come in a variety of shapes, profiles and forms.
Astragal: A small convex moulding. - Bead: A convex moulding, usually semi-circular. There are a variety of different types of beads, such as angle bead, nosing bead, double bead and so on.
Bead: A convex moulding, usually semi-circular. There are a variety of different types of beads, such as angle bead, nosing bead, double bead and so on.
Beak moulding: A moulding that is shaped into a beak-like form.
Bed-mould: Part of the cornice that appears under the projecting edge.
Cong: A concave moulding. - Cyma: Sometimes called a wave moulding, this is a double curvature that is used as the uppermost element in a cornice.
Cyma: Sometimes called a wave moulding, this is a double curvature that is used as the uppermost element in a cornice.
Echinus: Sits below the abacus and above the necking of a column.
Ovolo: A convex moulding, also known as a quarter round.
Reed: A series of convex mouldings running parallel to each other. Also known as reed moulding or reeding.
Scotia: One of the elements used in the attic base of columns, it is a concave moulding between two fillets.
String course: A horizontal moulding usually made from a series of complex profiles.
Three-quarter hollow: A three-quarter concave profile. - Three-quarter moulding: A three-quarter convex profile.
Three-quarter moulding: A three-quarter convex profile. - Thumb moulding: A thumb-shaped moulding.
Thumb moulding: A thumb-shaped moulding. - Torus: A semi-circular, convex moulding that is one of the distinctive elements in the attic base of columns.
Torus: A semi-circular, convex moulding that is one of the distinctive elements in the attic base of columns.
NB Drawing for Understanding, Creating Interpretive Drawings of Historic Buildings, published by Historic England in 2016 defines mouldings as: 'Continuous projecting or inset architectural embellishment. Mouldings are used to enrich, emphasise and separate architectural components by casting shadows and otherwise making the item they form part of visually distinct from their surroundings. They are to be found on doorways, structural beams and other parts of buildings. Their distinctive style is often used as a means of dating the part of the building on which they are found.'
In classical architecture, an entablature is a horizontal assemblage of moldings, bands and detailing in the upper portion of a building. It is placed along the top of, and therefore supported by, vertical columns. It is usual for the entablature to rise in horizontal layers up to either the roof, triangular pediment or arch.
The term is derived from the Latin word for table. This is appropriate since the entablature resembles a table top resting on the legs of the columns.
The entablature varies corresponding to the distinguishing features of the main architectural orders Doric, Ionic and Corinthian. However, traditionally the entablature includes three main parts:
Architrave at the lowest level. - Frieze in the middle.
Frieze in the middle. - Cornice at the top.
Cornice at the top. - Entablatures can also be found in building interior design. Here, they may be used to frame an entire room, frame a door header, or act as a fireplace mantel. The intention is that they provide aesthetic quality and order to a room and elevate the design.
Entablatures can also be found in building interior design. Here, they may be used to frame an entire room, frame a door header, or act as a fireplace mantel. The intention is that they provide aesthetic quality and order to a room and elevate the design.
In classical architecture, a pedestal is used as a base to support columns, statues or other ornaments. A classical pedestal may be square, octagonal or circular and is usually made up of three elements:
Plinth: This is the lowest part of the base of a column or pedestal. The plinth distributes the columns weight.
Die: This is a rectangular block that separates the base from the cap.
Cap: This is the uppermost element in a pedestal.
Roman architects were the first to introduce pedestals in this form, primarily as a means of giving columns and arches a more imposing appearance. The higher the column, the higher the pedestal.
A concrete pedestal is a compression element provided to carry the loads from supported elements like columns, statues etc. to footing below the ground.
The word fillet comes from the Latin filum, meaning thread
In classical architecture, a fillet is a narrow band with a vertical face. Fillets are often interposed as rectangular or square ribbon-like bands between curved mouldings and ornaments. They may also be found between the flutings of columns.
Types of fillet include: -
Raised: A fillet that is raised in a band from an architectural element.
Scotia: A concave moulding between two fillets. This is also one of the elements used in the attic base of columns.
Sunk: A fillet that is depressed in a band between two other architectural elements.
Tnia: A fillet that is part of the entablature and positioned directly above the architrave.
In modern construction, the term fillet can be used to refer to any thin strip of material, for example a tile fillet, in which roof tiles are set into mortar beneath a parapet to form a flashing, or a mortar fillet, used in place of a flashing at the joint between roof slates and a wall.
In engineering, the term fillet can be used to refer to a round joint between two parts connected at an angle.
A portcullis is a strong grate - commonly made of wood, iron or both - that is typically incorporated into the walls of a castle or other type of fortification. These devices were often used in the middle ages
The word portcullis comes from the French, porte coleice or "sliding gate".A portcullis is situated within vertical grooves that are inset within the jambs of a doorway so the heavy structure can move up and down.
A pitched roof is a roof that slopes downwards, typically in two parts at an angle from a central ridge, but sometimes in one part, from one edge to another. The pitch of a roof is its vertical rise divided by its horizontal span and is a measure of its steepness.
A pitched roof is in contrast to a flat roof which, technically, is any roof with a slope less than 10; however, in practise they tend to be much shallower, commonly being expressed as a gradient and can be anywhere from 1:40 to 1:80. For more information, see Flat roof.
The National Calculation Methodology (NCM) modelling guide (for buildings other than dwellings in England) 2013 edition, published by the Department for Communities and Local Government (DCLG) considers that a pitched roof is a 'Roof with pitch greater than 20 deg and less than or equal to 70 deg if the pitch is greater than 70 deg, it must be considered a wall.'
The two basic construction methods of pitched roofs are:
Cut roof: A traditional method of cutting timber on-site and building up the roof using rafters, joists, purlins, ridge boards, etc.
Truss roof: Prefabricated trusses which are delivered to site and erected.
There are also a number of other framed constructions, such as portal frame roofs.
Types of pitched roof - There are several different types of pitched roof:
There are several different types of pitched roof:
Mono pitch roof - A mono pitch roof is one which slopes from one side of a building (or part of it) to another. The mono pitch roof was commonly used to form extensions in Victorian times and is still used in a similar fashion today. In domestic construction, it typically comprises a series of rafters fixed to walls at either end of the roof span which support battens to which the roof covering is fixed.
A mono pitch roof is one which slopes from one side of a building (or part of it) to another. The mono pitch roof was commonly used to form extensions in Victorian times and is still used in a similar fashion today. In domestic construction, it typically comprises a series of rafters fixed to walls at either end of the roof span which support battens to which the roof covering is fixed.
Couple roof - Often referred to as the simplest form of pitched roof, the couple roof comprises two lengths of timber (rafters) leaning against one another, tied where they meet at the top.
Often referred to as the simplest form of pitched roof, the couple roof comprises two lengths of timber (rafters) leaning against one another, tied where they meet at the top.
Closed couple roof - By adding ceiling joists, a length of timber running horizontally between the rafter feet, to the couple roof form, the structure becomes much more secure. The joist acts as a tie preventing the outward deflection of the wall and increases the potential roof-span. they can also be used to support a flat ceiling.
By adding ceiling joists, a length of timber running horizontally between the rafter feet, to the couple roof form, the structure becomes much more secure. The joist acts as a tie preventing the outward deflection of the wall and increases the potential roof-span. they can also be used to support a flat ceiling.
Collar roof - By raising the height of the ceiling joists higher than the bottom of the rafters, the collar roofa llows upper rooms to be constructed partly in the roof space, leading to some economies by slightly reducing the height of the external walls and therefore the amount of brickwork needed.
By raising the height of the ceiling joists higher than the bottom of the rafters, the collar roofa llows upper rooms to be constructed partly in the roof space, leading to some economies by slightly reducing the height of the external walls and therefore the amount of brickwork needed.
Purlin roof - In order to increase potential roof spans without compromising wall stability, increasing rafter sizes or attracting extra costs, purlins can be introduced. By installing a purlin into the roof structure, rafters are given extra support and no longer needed to be as thick and heavy.
In order to increase potential roof spans without compromising wall stability, increasing rafter sizes or attracting extra costs, purlins can be introduced. By installing a purlin into the roof structure, rafters are given extra support and no longer needed to be as thick and heavy.
On flat roofs, a 'warm roof' is one in which the insulation layer is laid on top of roof structure. This results in the structural deck and its supports being at a temperature closer to that of the buildings interior. This is as opposed to a 'cold roof' in which the insulation is below, or within the roof structure, and so the roof structure is closer to the outside temperature.
An 'inverted roof' is a form of warm roof in which the waterproofing layer is beneath the thermal insulation rather than above it.
On pitched roofs, the definition of warm or cold can relate to the entire space below the pitch of the roof, but above the ceiling. This means that a warm roof might be one in which the insulation is installed in line with the rafters (rather than above the roof structure), so that the space under the pitch, ie a loft, attic or other space is insulated and warm. A cold roof in this case would typically have insulation laid above the ceiling so that the loft space below the pitched roof is cold relative to the rest of the property.
An alcove is a recess that opens into a room or other space, partially enclosed by vertical elements such as walls, pillars, balustrades, and so on.
In medieval architecture, alcoves often featured in halls, separated from the main space by curtains or timber partitions. In Roman and Renaissance architecture, alcoves were adapted to become tall, elegant semi-circular spaces hollowed out of thick walls and used to display statues and sculptures.
In more modern architecture, bed and kitchen alcoves developed as a way of conserving space in constricted buildings such as residential apartments. They now often appear to one side of a chimney breast.
Smaller alcoves can be used to contain ornaments, shelving, and so on. When designed carefully they can create attractive focal points and enhance the character of a particular room.
Alcoves may be designed to blend into their surroundings as architectural features, and may include shelving, concealed lighting, a glass front and so on. Small rectangular or square box alcoves are popular in contemporary architecture, often painted a deeper, or contrasting, colour to the rest of the room. This helps to give a greater impression of depth.
When designing an alcove, or adapting a space to incorporate one, it is important to consider the space that will be 'lost', as often, to achieve the required recess, a wall will need to be brought forward. New runs of skirting or cornicing may also be required, as well as new positions for power sockets.
It should also be borne in mind that there could be services running through the existing wall, which may need to be re-routed, or may need to remain accessible.
Cracking can also be a problem where new plaster meets old plaster. To avoid this, the wall should be properly skimmed to a minimum of 400 mm beyond the point where the two types of plaster meet. Manufacturers offer a wide variety of plaster casts for whole alcoves.
A mansard roof, also known as a French or curb roof, is a roof characterised by that fact that each of its four sides has two pitches, the lower pitches being steeper than the upper pitches. It is similar to a gambrel roof but differs in that it displays the same profile on all sides (whereas a gambrel roof has vertical gables at either end). The lower slope is commonly fitted with dormer windows.
Mansard roofs allow for increased space beneath their steeper sides. They maximise headroom inside the upper storey of the building whilst lowering, what would if it were simply-pitched, be a very tall roof. The mansard form can also help water runoff, as the pitch increases towards the eaves, where the runoff is likely to be at its greatest.
When viewed from near the building at ground level, the upper slope is often not visible.
The commonly-attributed earliest example of a mansard roof is the Louvre, designed by Pierre Lescot around 1550. It was popularised in the French Baroque period by Francois Mansart and became widely used during the Second French Empire (1852-1870) as well as in the United States and Europe. One of the factors attributable for its popularity in France was that houses were taxed by height or the number of storeys below the roof. The design of the mansard enabled the creation of an additional floor without having to pay additional tax.
A gable is a section of wall located at the end of a pitched roof, between the edges of the intersecting pitches. It is usually triangular and extends from the eaves to the ridge, although the shape and detailing depends on the particular structural system used for the roof. The term gable wall (or gable end) is used to refer to the gable and the whole wall below it.
In classical architecture, a gable was referred to as a pediment.
As well as being designed to be aesthetically pleasing, a gable should be capable of preventing water from entering the intersection between wall and roof. This can be done by carrying the roof out over the top of the end walls, or by raising the end walls above roof level to form a parapet capped with a waterproof coping.
The latter design can take several different forms in terms of its outline. Where roofs are of a steep pitch, gables are sometimes decorated with stepped or curved forms, ornamented with grotesques, statues, scrolls, and so on. A common example is a crow-stepped gable, also known as a stepped gable or corbie step, which takes the form of a stair-step pattern at the top of the stone or brick parapet wall which projects above the roofline. They can be designed with integral windows or vents (as in the above image).
Gables tend to be an inappropriate design for buildings located in hurricane regions since the wind pressures exerted on the gable end can cause the roof to fail.
Rather than constructing gables from masonry, they can be formed by prefabricated spandrel panels. These panels can be installed quickly by crane, and mean that roofing contractors can complete the wall elements under the roof rather than having to get brick or block layers to return to site.
The term 'fascia' derives from Latin and means band or ribbon. In classical architecture, a fascia was typically a plain, wide band that ran directly above the columns, across the bottom of the entablature. These fascias were often ornately-carved stone and formed part of a cornice.
In more modern buildings, a fascia, sometimes referred to as a fascia board, is a horizontal band which runs along the lower edge of a roof where it overhangs the buildings outer walls, helping close the gap between the roof and the wall.
Fascia boards are typically fixed to the vertical faces of the rafters that form the roof, while soffit boards will typically be fixed to the underside of the rafters to form a 'soffit'. In combination, these elements help to seal the roof at its edges. The fascia may also be used to support gutters, and often supports the lower edge of the bottom row of roof tiles.
Fascia boards are often made of timber boards, uPVC or a non-corrosive sheet metal. They can be manufactured in a range of shapes and colours to suit the style of the building in question.
The word 'gutter' originates from the Latin 'gutta' meaning 'a drop' which developed to mean a groove cut into something, or a furrow made by running water.
A rain gutter, also known simply as a gutter or guttering, is part of a buildings water discharge system. It is a trough or channel that runs around the perimeter of a roof, and collects rainwater runoff from the roof, discharging it, usually to rainwater downpipes which convey it to a drainage system. This protects the exterior surfaces of the building and its foundations from damp and potentially suffering damage.
The Building Regulations Part H, Drainage and water disposal, requires that adequate provision is made for rainwater to be carried from the roof of buildings. Approved document H suggests that to achieve this, roofs should be designed with a suitable fall towards either a surface water collection channel or gutter that surface water to vertical rainwater downpipes, which in turn connect the discharge to the drainage system.
The size of guttering can be determined from the area of the roof (metres) and the anticipated rainfall intensity (litres/sec/sq. m - the amount of water likely in a 2-minute rainstorm). There are a number of calculators that can be used to size gutters and rainwater downpipes based on this information.
Commonly used gutter designs include: -
Box gutters: These are rectangular and boxed into the roof so as not to be visible.
Fascia (or eaves) gutters: The gutter and fascia are combined so that the gutter appears to be build in to the eaves.
Square gutters: Typically fixed to the outside face of the fascia, square-shaped and preferable in areas of heavy rainfall.
Round gutters: Typically fixed to the outside face of the fascia, and half-circle-shaped.
Quad (or D) gutters: Typically fixed to the outside face of the fascia, they are available in a range of different widths and profiles.
Traditionally, guttering was made out of lead, which was largely replaced from the late-18th century on by cast iron. This enabled gutters to be mass produced. Conservation projects will still specify cast iron gutters for restoration but these can also be replaced with cast aluminium.
Domestic guttering is typically made from uPVC sections, which are easily installed, cost-efficient and lightweight. They require minimal maintenance, apart from ensuring they do not become blocked, and have a good life expectancy. Standard components are available to allow them to be fixed, as well as corner section, connections for downpipes, and so on.
Gutters may also be made from materials such as aluminium alloy, galvanised steel, stainless steel, copper, zinc, and so on.
Sewerage (the sewer system), is the underground networks of pipes that carries sewage (waste water and excrement), waste water and surface water run-off, from buildings to treatment facilities or disposal points.
A sewer is; 'A pipe or channel taking domestic foul and/or surface water from buildings and associated paths and hardstandings from two or more curtilages and having proper outfall' Ref The SuDS Manual (C753), published by CIRIA in 2015.
Types of sewer include: -
Sanitary sewer: Used solely for carrying sewage.
Surface water sewer: Used to drain groundwater and excess water from impervious surfaces.
Combined sewer: Used to carry both sewage and surface water. This type of sewer can lead to water pollution problems when overflow conditions are experienced.
Effluent sewer (sometimes referred to as Septic Tank Effluent Drainage (STED) or Solids-Free Sewers (SFS)) : These collect remaining sewage from septic tanks and carry it to a treatment plant.
Separate sewer: For surface water or foul sewage, but not a combination of both.
There are a number of ways of moving the contents of sewers:
Gravity sewers use differing elevations to facilitate movement.
Force mains use pumps where sewers are at a lower elevation than the destination.
Vacuum sewers use differential atmospheric pressure. - A sewerage undertaker is: 'A collective term relating to the statutory undertaking of water companies that are responsible for sewerage and sewage disposal, including surface water from roofs and yards of premises.' Ref The SuDS Manual.
A sewerage undertaker is: 'A collective term relating to the statutory undertaking of water companies that are responsible for sewerage and sewage disposal, including surface water from roofs and yards of premises.' Ref The SuDS Manual.
In September 2010, the government announced that most private sewers that connected to the public sewer network would be transferred to the ownership of the regulated sewerage companies in England and Wales. Private sewers that were connected to the public sewer network before 1 July 2011 were transferred on 1 October 2011.
NB -
A drain is a pipe that serves only one building, conveying water and waste water to a sewer. A lateral drain is a section of drain positioned outside the boundary of a building, connecting with the drains from other buildings to become a sewer.
Combined Sewer Overflow (CSO) is: A structure on a combined or partially separate sewer system that allows the discharge of flow in excess of that which the sewer is designed to carry, usually to a receiving surface water body. Ref The SuDS Manual.
In classical architecture, anta (plural: antae) are the posts or pillars that project slightly at the end of a wall. They usually flank the doorways of, or entrances to, Greek or Roman temples.
The difference between antae and columns or pillars is that they are directly connected with the temple walls. They evolved from the structural posts made of timber that were used to reinforce the brick walls of more primitive palaces or temples.
They use began with a load-bearing function, but they became more decorative as the wall materials themselves became sufficient to support the structure. Anta are a forerunner of the pilaster.
Temples would often have columns positioned between antae. These were described as being in antis.
In classical architecture, a colonnade is a row of columns spaced at regular intervals in a similar way to a balustrade. They can be used to support a horizontal entablature, an arcade or covered walkway, or as part of a porch or portico. The most iconic example of a portico lined with a colonnade is the Parthenon in Greece. Colonnades can also be used to line open courtyards, and may often be a feature of landscape design.
The use of colonnades dates back to Ancient Greece and Roman architecture where they were used for large public buildings to border open spaces, such as temples and marketplaces.
Colonnades were later used in Baroque and Neoclassical architecture for buildings such as museums and courthouses to create an aesthetic of importance and grandness, such as the Lincoln Memorial in Washington D.C (see image above).
Colonnade size and design can vary. They are usually made from materials such as marble, limestone and painted timber. Larger columns are used for more monumental buildings, while smaller and more slender columns can be found in the Regency architecture of formal homes.
An ancillary area of a building is an area that supports the function/s of the primary areas, that is, it is not part of the primary purpose of the building, but is required in order that the primary purpose can function.
Examples of ancillary areas include: -
Plant rooms. - Cleaners rooms.
Cleaners rooms. - ICT rooms.
ICT rooms. - Building services rooms.
Building services rooms. - Storage rooms.
Storage rooms. - Circulation spaces.
Circulation spaces. - In shared buildings, an ancillary area might support more than one occupant, e.g. a shared kitchen, meeting spaces, utility areas, and so on.
In shared buildings, an ancillary area might support more than one occupant, e.g. a shared kitchen, meeting spaces, utility areas, and so on.
In residential buildings, ancillary areas include spaces which do not form part of the main dwelling directly, but nonetheless add some useful value, e.g. patio area, office, garage, conservatory, porch, utility room, and so on.
A bay window is a multi-panel window that projects outward beyond the external wall of a building. This outward projection forms a bay or interior recess and is supported by a sill height wall. Bay windows are typically rectangular or polygonal, and the most common internal angles are 90, 135 and 150.
Bay windows are a prominent feature of Victorian domestic architecture but were originally incorporated into designs during the English Renaissance period as a means of making a room appear larger, providing better views and admitting more natural light than a window which was flush with the wall line.
The interior recess created by a bay window can be used for storage by enclosing the lower area, or as a window seat with the addition of cushions and other soft furnishings. Alternatively, it can be used as a space to display decorative items, plants, and so on.
However, a bay window can require more heating or cooling to maintain a comfortable internal temperature due to the increased surface area of glazing. Consideration must also be given to the structural stability of the building foundations, as they must be capable of supporting the protruding windows and roof above.
In modern architecture, bay windows underwent a revival to become a characteristic feature of the Chicago School. Today, bay windows can be found in all types of domestic architecture as well as in apartment buildings.
There are several variations, including: -
Canted: A bay window with a flat front and angled sides.
Bow: A bay window which is curved or arc-shaped.
Oriel window: This is a bay window found on an upper floor, typically supported from below by a corbel or bracket. This type of window allows the floor space to be extended without the dimensions of the foundation needing to be changed.
Mashrabiya: Highly decorative enclosed balconies that are characteristic of Arab architecture.
Windows are openings fitted with glass to admit light and allow people to see out. They are often openable to allow ventilation. Rooflights (sometimes described as roof lights or skylights) are windows built into the roof of a building.
Rooflights are effective at allowing natural light deep into the centre of a building, particularly where it is not possible to install windows in perimeter walls or where privacy is needed. Where they are openable, they can also be effective at promoting natural ventilation, as they tend to be at the top of buildings and so can benefit from the stack effect. They may also be used to allow access to roofs or to roof terraces.
Some rooflights however can be seen as a poor design solution, contributing little to the architectural form of a building, and simply creating a hole in a roof because without them there would be insufficient natural light. They can also suffer from ponding, dirt accumulation and staining.
Rooflights must have safety glazing, and if they are out of reach, may need a mechanism or motor to open them.
In some areas, some rooflights may be considered a permitted developments, not requiring planning permission. However, it is sensible to consult with the local planning authority to check this.
BS EN 14351-1 (Windows and doors. Product standard, performance characteristics. Windows and external pedestrian doorsets) suggests that the term roof window refers to a window that is in the same plane as the surrounding roof, and has a minimum pitch of 15 degrees. This is as opposed to 'rooflights' which by this definition are installed on an upstand, and so are not in the same plane as the surrounding roof.
dormer is a small roofed structure that projects outwards from the main pitched roof of a building. Dormers can be included in the original construction of a building or added on subsequently.
Dormers are becoming more common in homes as they can help create extra headroom in spaces that may otherwise be too small or too low for habitation. They enable the creation of rooms in the roof or loft without needing to construct a new storey. Dormers will typically have dormer windows set into them to allow light and ventilation.
There are a number of different types of dormers including:
Box roof/flat roof: The plane of the roof is horizontal. This type of dormer provides the most space and floor area inside the building.
Gable: These have a gable roof, with the front of the dormer being flat with a pitched roof and vertical sides.
Hip roof: The roof comprises of three sloping panels that meet at the ridge.
Arched/eyebrow: This is similar to the hipped dormer but has an arch or curve which allows it to blend in to the existing roof.
The insertion of dormer windows as part of a loft conversion does not normally require planning permission. However, If the roof space is altered or extended and it exceeds specified limits and conditions, permission may be necessary. It may also be necessary to obtain permission within conservation areas, National Parks, Areas of Outstanding Natural Beauty or the Broads, or if the building is listed.
The term 'glazing' refers to the glass component of a building's faade or internal surfaces.
Historically, the external windows of buildings were generally single glazed, consisting of just one layer of glass, however, a substantial amount of heat is lost through single glazing, and it also transmits a significant amount of noise, so mulit-layerd glazing systems were developed such as double glazing and triple glazing.
Double glazing comprises two layers of glass separated by a spacer bar (also known as a profile); a continuous hollow frame typically made of aluminium or a low heat-conductive material. The spacer bar is bonded to the panes using a primary and secondary seal which creates an airtight cavity, typically with 6-20 mm between the two layers of glass. This space is filled with air or with a gas such as argon, which improves the thermal properties of the window. Larger cavities may be provided to achieve greater sound reduction.
A desiccant in the spacer bar absorbs any residual moisture within the cavity, preventing internal misting as a result of condensation.
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are used to measure how effective elements of a buildings fabric are as insulators. That is, how effective they are at preventing heat from transmitting between the inside and the outside of a building. Typically, the U-value of single glazing is around 4.8 to 5.8 W/mK, whilst double glazing is around 1.2 to 3.7 W/mK. NB Triple can achieve a U-value below 1 W/mK.
Thermal performance is affected by the quality of the installation, the inclusion of thermal breaks in the frame, suitable weather seals, the gas used to fill the units, and the type of glass used. Low-e glass has a coating added to one or more of its surfaces to reduce its emissivity so that it reflects, rather than absorbs, a higher proportion of long-wave infra-red radiation..
The sound reduction achieved by single glazing (6 mm thick) is typically around 27 dB, whilst double glazing (100 mm air space) is around 42 dB.
The sound reduction achieved by double glazing is affected by:
Good installation to ensure airtightness - Sound absorbent linings to the reveals within the air space.
Sound absorbent linings to the reveals within the air space.
The weight of glass used the heavier the glass, the better the sound insulation.
The size of air space between layers - up to 300 mm.
A glazier is a tradesperson whose job is to measure, cut, fit, instal, repair - and sometimes remove - glass within structures. A glazier may also be referred to as a glass installer or a fenestration installer.
Responsibilities - Glaziers deal with glass in windows, partitions and doors in most types of buildings. They work with plate glass, sheet glass, structural glass, mirrors, mirror frames, leaded glass and other types of speciality glass.
Glaziers deal with glass in windows, partitions and doors in most types of buildings. They work with plate glass, sheet glass, structural glass, mirrors, mirror frames, leaded glass and other types of speciality glass.
The responsibilities of being a glazier can be split into two areas - physical requirements and strategic skills.
In terms of physical requirements, candidates must be able to lift, bend and carry. They will often benefit from being able to work well with their hands. Typical physical tasks might include:
Removing old or broken panes, beading and putty from frames.
Fitting new glass and ensuring seals are watertight.
Shaping glass with appropriate tools. - Building the framework for the glass.
Building the framework for the glass. - Lifting glass and fitting it into place
Lifting glass and fitting it into place - Working with materials such as films that can that can alter the safety, transparency, reflectance, emissivity and so on of glass.
Working with materials such as films that can that can alter the safety, transparency, reflectance, emissivity and so on of glass.
Strategic skills might include: -
Assessing risks. - Choosing the appropriate glass.
Choosing the appropriate glass. - Estimating and measuring new glass.
Estimating and measuring new glass. - Making decorative glass panels or double glazing units.
Making decorative glass panels or double glazing units.
Following diagrams and measurements to cut glass to size.
Knowing about construction materials and techniques. - Having customer service and communication skills.
Having customer service and communication skills. - Paying attention to detail.
Paying attention to detail. - Working well with others.
Working well with others. - Glazier tools
Glazier tools - Glaziers use manual tools (such as glass cutters, suction cups and glazing knives) and machines (such as saws, drills, cutters and grinders). Some glaziers also use computers to assist with measurements so they can reduce waste.
Glaziers use manual tools (such as glass cutters, suction cups and glazing knives) and machines (such as saws, drills, cutters and grinders). Some glaziers also use computers to assist with measurements so they can reduce waste.
Their work may include shower and tub enclosures as well as rooflights, automatic glass doors and so on. In certain instances (such as those that involve work at height), they must have an understanding of scaffolding and ladders in order to comply with Work at Height Regulations (2005) requirements. Glaziers are also required to wear the appropriate safety clothing and use proper safety equipment.
Becoming a glazier - Careers in the construction industry generally require on the job experience of some kind. However, it may be necessary to acquire a Construction Skills Certification Scheme (CSCS) card before being considered for a job on a construction site.
Careers in the construction industry generally require on the job experience of some kind. However, it may be necessary to acquire a Construction Skills Certification Scheme (CSCS) card before being considered for a job on a construction site.
The glazier career path includes two main routes: apprenticeships or direct application based on past work within the construction industry.
Apprenticeship - Fenestration installation companies sometimes offer apprenticeships, typically to people older than 16 years old. Apprentices act as employees and generally gain experience by working on the job for 30 hours per week. They will also be expected to attend college or training programmes.
Fenestration installation companies sometimes offer apprenticeships, typically to people older than 16 years old. Apprentices act as employees and generally gain experience by working on the job for 30 hours per week. They will also be expected to attend college or training programmes.
The standard requirement for an intermediate apprenticeship includes GCSEs (most often including English and maths) or an equivalent. Its also possible to start as a glazier's assistant and then train on the job.
Direct application - It is possible to apply directly for a job as a glazier at a construction or fenestration company. New glaziers generally start out as assistants. Experience in construction and maths skills are generally required. Some employers may ask for two or more GCSEs (including English and maths) at grades 9 to 4 (A* to C) or an equivalent. On the job experience in carpentry, joinery or window manufacturing may also be advantageous.
It is possible to apply directly for a job as a glazier at a construction or fenestration company. New glaziers generally start out as assistants. Experience in construction and maths skills are generally required. Some employers may ask for two or more GCSEs (including English and maths) at grades 9 to 4 (A* to C) or an equivalent. On the job experience in carpentry, joinery or window manufacturing may also be advantageous.
Career development - Over time, an experienced glazier may focus on speciality projects such as renovations or restorations of historic buildings. Some also become involved in the automotive industry and work on windscreen replacement and repair.
Over time, an experienced glazier may focus on speciality projects such as renovations or restorations of historic buildings. Some also become involved in the automotive industry and work on windscreen replacement and repair.
Being a glazier may mean working at commercial and residential sites. It may also involve a significant amount of customer interaction, particularly if there is the need for speciality design work.
The term low-e glass is used to describe glass that has a coating added to one or more of its surfaces to reduce its emissivity.
Emissivity is an indicator of the amount of long-wave infra-red radiation which a surface (such as the faade of a building) will emit to its surroundings. According to Kirchoff's law the emissivity of a surface is equal to its radiant absorptivity at a given temperature and wavelength. It is expressed as a proportion of 1, so if a surface absorbs 40% of the long-wave infra-red radiation incident on its surface, it has an emissivity of 0.4.
All bodies which are hotter than 0K emit thermal radiation and absorb thermal radiation. In general, the higher the temperature of a body, the lower the average wavelength of the radiation it emits. The range of terrestrial temperatures experienced within the built environment is comparatively cold compared to the sun and so they are radiating at a much longer wavelength. This anomaly allows us to distinguish between short-wave solar radiation and long-wave infra-red radiation (terrestrial radiation).
Typically, glass is relatively transparent to short-wave solar radiation, but opaque to long-wave infra-red radiation. This is said to produce a greenhouse effect, where solar radiation enters a space, and heats it up, but the resulting long-wave infra-red radiation emitted by the hot internal surfaces is unable to escape.
However, glass has a relatively high emissivity. This means that although it does not transmit long-wave infra-red radiation incident on its surface, it does absorb it. This absorbed heat is then re-radiated.
Low-e coatings can be used to reduce the effective emissivity of the surface of glass so that it reflects, rather than absorbs, a higher proportion of long-wave infra-red radiation.
In cooler climates this means that long-wave infra-red radiation that builds up inside a building is reflected by the glass back into the space, rather than being absorbed by the glass and then partially re-radiated to the outside. This reduces heat loss and so the need for artificial heating.
In hotter climates, a low-e coating means that long-wave infra-red radiation outside the building is reflected back out of the building, rather than being absorbed by the glass and then partially re-radiated to the inside. This reduces the heat build-up inside the building and so the need for cooling. In hotter climates, a low-e coating might be used in conjunction with solar-control glass to reduce the amount of short-wave solar radiation entering the building.
Low-e coatings can reduce the emissivity of glazing from more than 0.8 to 0.2 or even as low as 0.04. Coatings tend to be either hard pyrolytic coatings which are applied to molten glass, or soft sputtered coatings, which generally need to be protected within the sealed unit.
A thermal bridge (sometimes referred to as thermal bridging, a cold bridge or thermal bypass) describes a situation in a building where there is a direct connection between the inside and outside through one or more elements that are more thermally conductive than the rest of the building envelope.
As a result, there will be wasteful heat transfer across this element, its internal surface temperature will be different from other, better insulated internal surfaces and there may be condensation where warm, moist internal air comes into contact with the, potentially cold, surface. This condensation can result in mould growth.
Thermal bridges are common in older buildings, which may be poorly constructed, poorly insulated, with single skin construction and single glazing.
In modern buildings, thermal bridging can occur because of poor design, or poor workmanship. This is common where elements of the building penetrate through its insulated fabric, for example around glazing, or where the structure penetrates the building envelope, such as at balconies.
However, as buildings have become better insulated, with increasingly strict regulation, so thermal bridges that might previously have been considered insignificant in terms of the overall thermal performance of a building, can actually be the cause of considerable thermal inefficiency. There is the potential for such inefficiency at every opening and every junction (even in party walls).
Thermal bridges can be categorised as 'repeating' for example where wall ties regularly bridge the cavity, or 'non-repeating' such as a wall junction or lintel.
The Approved Documents to Part L of the building regulations (Conservation of fuel and power) state that 'The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps within the various elements, at the joints between elements and at the edges of elements such as those around window and door openings.'
They require that where unaccredited construction details are used, generic linear thermal bridge values must be increased by levels (depending on the building type) set out in the Approved Documents for the calculations of building emission rates (BER) or dwelling emission rates (DER).
Thermal bridges in completed buildings can be revealed with thermal imaging cameras (see Thermographic survey), but they can be very difficult to rectify, particularly if they are repeated throughout a building.
The term damp proofing refers to types of moisture control that are applied to walls and floors to prevent damp from setting in or spreading in a building.
Damp problems are among the most frequent problems encountered in buildings, particularly older buildings which may have been constructed without a damp-proof membrane.
Damp may be apparent from: -
Damp patches. - Mould growth.
Mould growth. - Mildew, salts, staining and 'tide marks'.
Mildew, salts, staining and 'tide marks'.
Damage to surface finishes, such as blistering paint and bulging plaster.
Corrosion and decay of the building fabric. - Slip hazards.
Slip hazards. - Frost damage.
Frost damage. - Poor performance of insulation.
Poor performance of insulation. - Damage to equipment, or electrical failure.
Damage to equipment, or electrical failure. - The most common causes of persistent damp in buildings are:
The most common causes of persistent damp in buildings are:
Condensation (surface or interstitial). - Rising damp.
Rising damp. - Penetrating damp.
Penetrating damp. - The two most common damp proofing techniques are:
The two most common damp proofing techniques are:
Installation of a damp-proof course. A damp-proof course is a barrier, usually formed by a membrane built into the walls of a property, typically 150 mm above ground level, to prevent damp rising through the walls. Damp-proof courses are now required in the construction of new buildings to prevent rising damp and in some situations to prevent penetrating damp.
Damp proof courses can also be retrofitted to existing buildings by the injection of water-repellent chemicals. Treatment generally also involves remedial work to any corroded or decayed elements of the building fabric, as well as hacking off and replacing existing plaster to a height of 1 m.
For more information, see Damp proof course.
Installation of a damp-proof membrane (DPM). Typically, a DPM is a polyethylene sheet laid under a concrete slab to prevent the concrete from transmitting moisture through capillary action.
For more information, see Damp proof membrane.
Other damp proofing techniques include: -
Integral damp proofing: Concrete production can involve the addition of materials to make it more impermeable.
Surface coating: Waterproof surface materials can be used internally or externally, such as render or waterproof plaster.
Cavity wall systems: A cavity separates the interior walls from the exterior walls.
Pressure grouting: This can fill in cracks and joints in masonry.
Colourless water-repellent treatments. - However, it is important to note that damp is often just a symptom of another problem in a building, such as a lack of ventilation, drainage problems, cracks in walls, missing tiles or leaking pipework. It is important therefore that the underlying problem is rectified before other treatments are applied.
However, it is important to note that damp is often just a symptom of another problem in a building, such as a lack of ventilation, drainage problems, cracks in walls, missing tiles or leaking pipework. It is important therefore that the underlying problem is rectified before other treatments are applied.
A stain, or staining, is the visible discolouration of a surface caused by the interaction of two dissimilar materials.
Stains can be accidental, intentional, or can be the result of the deterioration of materials, such as the rust which forms on iron or the patina that develops on bronze.
Stained glass is a type of glazing material that is intentionally coloured (stained), either by the addition of metallic salts during the manufacturing process, or by having colour applied to its surface and then being fired in a kiln to fuse the colour to the glass. For more information, see Stained glass. Timber can also be stained to alter its appearance.
The severity of unintentional stains depends on the type of material affected. For example, even small stains can cause serious damage to sensitive furnishings such as carpets, curtains and upholstery.
In relation to buildings and structures, some types of staining can be seen as adding character, however it may be an indication of an underlying problem:
'Tide marks on walls can be indicators of damp problems, particularly in older buildings which may have been constructed without a damp-proof membrane.
Pattern staining occurs when a substance settles or emerges on the internal or external surface of a material. There are various causes of pattern staining, such as pollution deposition, salt expulsion, staining from other materials, and so on.
Algae soiling is a growth on buildings that is caused by organic biological deposition, such as moss and lichens. Usually, these cause damage to building surfaces, and should be rectified.
In some instances, the appearance of bricks is affected by the development of stains. These may originate from materials in the brick or mortar, from adjacent materials or from outside sources such as cleaning agents. Each has a particular chemical composition and a unique means of removal. Identification of the origin of the stain is the first step in returning brickwork to its proper appearance.
Stains are often misidentified or mistaken for efflorescence. When correctly identified, efflorescence and stains can generally be removed, whereas inappropriate correction methods may result in further staining or damage to the brickwork.
Lime staining [see top image], also known as lime run-off, describes an effect that can come about when excess water flows through cementatious material. This water can dissolve calcium hydroxide (free lime) which is then deposited on the brick face. The calcium hydroxide is a soluble form of lime which is created as Portland cement hydrates. The initial staining can be removed with water and brushing before it carbonates. Once reaction has taken place, an acid solution will be necessary because the hard crust that forms when the lime has started to carbonate is much harder to remove.
Vanadium stains: These occur when vanadium oxide and sulfates are dissolved and result in a solution that may be quite acidic.
Iron staining: Usually appears as a stain to the mortar joint and can come from metal imbedded in the structure.
Manganese staining: Manifests itself as a dark brown or black staining concentrated along mortar joints.
White scum: Silicate deposits which appear as uneven white or grey stain on the brick face or mortar joints.
Acid burn: Unsightly and uneven yellow/gold staining caused by cleaning brickwork with muriatic acid.
Stains from external sources: Such as pollution, organic growth or runoff. Usually, the source and composition of these stains is obvious. Organic stains can include algae, mould or other organisms.
Stain removal is a type of maintenance procedure, and a common technique is jet washing with chemical cleaning agents.
Furnishings, sometimes referred to as soft furnishings or upholstery, are components that incorporate soft material and help create a pleasant and comfortable environment, and complement the furniture and fittings inside buildings. Furnishings can be made of fabric, chenille, velvet, silk, fur, faux-fur, cloth, foam, rubber, and so on.
Common types of furnishings include: -
Curtains. - Cushions.
Cushions. - Bedding and mattresses.
Bedding and mattresses. - Wall hangings and tapestries.
Wall hangings and tapestries. - Rugs.
Rugs. - Chair coverings.
Chair coverings. - Sofas.
Sofas. - Bean bags.
Bean bags. - Carpets.
Carpets. - Doormats.
Doormats. - Window Coverings.
Window Coverings. - Furnishings should be carefully selected and designed to enhance the quality of a room, often adding colour, texture and elegance to furniture. The soft material of some furnishings can also enhance the energy efficiency of a room by retaining heat and keeping it warm. They may also improve the sound insulation properties as soft materials absorb sound waves more effectively than hard surfaces which reflect sound back into the space and can result in echoes (or a longer reverberation time).
Furnishings should be carefully selected and designed to enhance the quality of a room, often adding colour, texture and elegance to furniture. The soft material of some furnishings can also enhance the energy efficiency of a room by retaining heat and keeping it warm. They may also improve the sound insulation properties as soft materials absorb sound waves more effectively than hard surfaces which reflect sound back into the space and can result in echoes (or a longer reverberation time).
The Furniture and Furnishings (Fire Safety) Regulations define requirements for the fire resistance for domestic upholstered furniture, furnishings and other products containing upholstery. These Regulations are enforced by Trading Standards.
According to HMRC, a fixture is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land in law (for example, a boiler).
This is as opposed to a chattel, which is, an asset, which is tangible and moveable (such as furniture). For example, a bath may be a fixture, but a fridge a chattel.
HMRC suggest that, a chattel may become a fixture if it is fixed to a building or land. For example, before it is installed in a building as part of a central heating system, a central heating radiator is a chattel. Once installed, it becomes a fixture.
This can be particularly important in the sale of property or in leasehold agreements, where the distinction between fixtures and chattels can determine ownership.
There are two key tests for identifying whether something is a fixture or a chattel:
The degree of physical affixation. This is not a conclusive test, but generally, the greater the degree of affixation (i.e. the damage that would be caused by removal), the more likely it is that an object is a fixture. The easier it is to remove, the more likely it is to be a chattel.
More conclusively, if the object is intended to be permanent and effect a lasting improvement to the property, it is a fixture. However, if any attachment is intended to be temporary and no more than is necessary for the object to be used and enjoyed, then it is a chattel.
However, these tests are not always used as the basis for determining the right to remove an object. Leasehold agreements will generally distinguish between the landlords fixtures and tenants fixtures which they may remove at the end of the lease (as long as they make good any damage). Similarly, conveyancing reports for the sale of property may state that certain fixtures are not being sold as part of the land.
Disputes can arise in particular in relation to expensive items such as paintings that may to a greater or lesser extent be a part of the building in which they are housed. Where there is doubt, it may be advisable to seek legal advice, and ensure that the position is set out in writing before signing any agreement.
In addition, the distinction between fixtures and chattels is important when calculating stamp duty land tax. Fixtures form part of the taxable value of the purchase, whereas chattels do not. The inclusion of fixtures can move the saleable price for tax purposes to the next stamp duty threshold, resulting in a much larger tax liability for the purchaser than had been expected. (Ref. HMRC, SDLTM04010 - Scope: How much is chargeable: Fixtures and fittings.)
HMRC suggest that: -
The following items are, however, confirmed as being assets that will normally be regarded as chattels:
Carpets (fitted or otherwise). - Curtains and blinds.
Curtains and blinds. - Free standing furniture.
Free standing furniture. - Kitchen white goods.
Kitchen white goods. - Electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property).
Electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property).
Light shades and fittings (unless recessed).
On the other hand, the following items will not normally be regarded as chattels:
Fitted kitchen units, cupboards and sinks. - Aga and wall-mounted ovens.
Aga and wall-mounted ovens. - Fitted bathroom sanitary ware.
Fitted bathroom sanitary ware. - Central heating systems.
Central heating systems. - Intruder alarm systems.
Intruder alarm systems. - Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
A deduction would, however, be appropriate for amounts properly apportioned to any plants growing in pots or containers.
According to HMRC, a chattel is an asset, which is tangible and moveable (such as furniture). This is as opposed to a fixture, which is an asset that is installed or otherwise fixed in or to a building or land so as to become part of that building or land... (such as a boiler). For example, a bath may be a fixture, but a fridge a chattel.
HMRC suggest that a chattel may become a fixture if it is fixed to a building or land. For example, before it is installed in a building as part of a central heating system, a central heating radiator is a chattel. Once installed, it becomes a fixture.
This can be particularly important in the sale of property or in leasehold agreements, where the distinction between fixtures and chattels can determine ownership.
There are two key tests for identifying whether something is a fixture or a chattel:
The degree of physical affixation. This is not a conclusive test, but generally, the greater the degree of affixation (ie the damage that would be caused by removal) the more likely it is that an object is a fixture. The easier it is to remove, the more likely it is to be a chattel.
More conclusively, if the object is intended to be permanent and effect a lasting improvement to the property, it is a fixture. However, if any attachment is intended to be temporary and no more than is necessary for the object to be used and enjoyed, then it is a chattel.
However, these tests are not always used as the basis for determining the right to remove an object. Leasehold agreements will generally distinguish between the landlords fixtures and tenants fixtures which they may remove at the end of the lease (as long as they make good any damage). Similarly, conveyancing reports for the sale of property may state that certain fixtures are not being sold as part of the land.
Disputes can arise in particular in relation to expensive items such as paintings that may to a greater or lesser extent be a part of the building in which they are housed. Where there is doubt, it may be advisable to seek legal advice, and ensure that the position is set out in writing before signing any agreement.
In addition, the distinction between fixtures and chattels is important when calculating stamp duty land tax. Fixtures form part of the taxable value of the purchase, whereas chattels do not. The inclusion of fixtures can move the saleable price for tax purposes to the next stamp duty threshold, resulting in a much larger tax liability for the purchaser than had been expected.
(Ref. HMRC, SDLTM04010 - Scope: How much is chargeable: Fixtures and fittings.)
HMRC suggest that: -
The following items are, however, confirmed as being assets that will normally be regarded as chattels
carpets (fitted or otherwise) - curtains and blinds
curtains and blinds - free standing furniture
free standing furniture - kitchen white goods
kitchen white goods - electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property)
electric and gas fires (provided that they can be removed by disconnection from the power supply without causing damage to the property)
light shades and fittings (unless recessed).
On the other hand, the following items will not normally be regarded as chattels
fitted kitchen units, cupboards and sinks - agas and wall mounted ovens
agas and wall mounted ovens - fitted bathroom sanitary ware
fitted bathroom sanitary ware - central heating systems
central heating systems - intruder alarm systems.
intruder alarm systems. - Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
Externally, any plants, shrubs or trees growing in the soil which forms part of the land, are not to be regarded as chattels.
A deduction would, however, be appropriate for amounts properly apportioned to any plants growing in pots or containers.
Specifications describe the products, materials, and work required by a construction contract. They do not include cost, quantity, or drawn information, and so need to be read alongside other information such as quantities, schedules, and drawings.
Specifications vary considerably depending on the stage to which the design has been developed, ranging from performance specifications (open specifications) that require further design work to be carried out, to prescriptive specifications (closed specifications) where the design is already complete.
Having a prescriptive specification when a contract is tendered gives the client more certainty about the end product, whereas a performance specification gives suppliers more scope to innovate and adopt cost-effective methods of work, potentially offering better value for money.
Typically, performance specifications are written on projects that are straight-forward and are well-known building types. For more information, see Performance specification.
Whereas prescriptive specifications are written for more complex buildings. For more information see: Prescriptive specifications.
They can also be used in combination. Items crucial to the design may be specified prescriptively (such as external cladding) whilst less critical items may be specified only by performance (such as service lifts).
Key to deciding whether to specify a building component prescriptively or not, is considering who is most likely to achieve best value, the client, the designers or the contractor:
Large clients may be able to procure certain products at competitive rates themselves (for example the government).
Some designers may have particular experience of using a specific product (although some clients may not allow designers to specify particular products as they believe it restricts competition and innovation and may relieve the contractor of their liability for 'fitness for purpose').
The contractor may be best placed to specify products that affect buildability.
Specifications should be developed alongside the design, increasing in level of detail as the design progresses.They should not be left until the preparation of production information. By tender, they should describe every aspect of the building in such a way that there is no uncertainty about what the contractor is pricing.
Aspects of the works are generally specified by:
Products (by standard, a description of attributes, naming (perhaps allowing equivalent alternatives) or by nominating suppliers).
Workmanship (by compliance with manufacturers requirements, reference to a code of practice or standards, or by approval of samples or by testing).
It should be possible to verify standards of products and workmanship by testing, inspection, mock-ups and samples, and documentation such as manufacturer's certificates.
Specifications should be structured according to work packages mirroring the separation of the works into sub-contracts. This makes it easier for the contractor to price and so may result in a more accurate tender. A standard classification system should be followed, such as Uniclass.
A bas-relief is a form of sculpture that is carved from a flat two-dimensional plane creating a three-dimensional appearance. The backgrounds are kept shallow from the raised features, usually between a fraction of an inch to a few inches deep. It was predominately used as a decorative feature in the ancient architecture of countries such as Egypt, Greece and Italy.
The term is French and is derived from the Italian basso-relievo (low relief).
A bas-relief is created in one of two ways:
By carving away material such as wood, stone, ivory, and so on.
By applying material, such as strips of clay, to the top of an otherwise smooth surface.
The natural contours and shape of that being represented should be retained, which means that the bas-relief can be viewed from different angles without undue visual distortion.
Alto-relievo (high relief) is where the technique is applied to much deeper backgrounds, usually of between a foot and several feet in depth.
In classical architecture, the tympanum is the triangular or segmental area enclosed by a pediment on the exterior of a building. The area of a triangular pediment is defined by the horizontal cornice along the bottom and the raking cornice that slopes along the sides. The area of a segmental pediment is defined by the segmental cornices along the sides. It is usual for the tympanum to be decorated with religious imagery or intricate bas-relief sculpture.
Tympana (plural) developed in Roman architecture as the semi-circular shape between the lintel of a doorway and the arch constructed above.
In European Gothic architecture, tympana were included over church portals and had a more vertical shape, meeting at a point at the top.
A mantel, also known as a fireplace mantel or mantelpiece, frames the opening of a fireplace and often covers part of the chimney breast.
It was originally developed in the medieval period for functional purposes, to serve as a hood that would prevent smoke from entering the room, diverting it back into the chimney. Since then it has generally become a decorative component, sometimes performing a function similar to a shelf. As a result of this change, use of the term mantel has expanded to include the jambs, mantel shelf and external accessories of a fireplace.
As fireplaces have become less common in new houses, in favour of modern heating methods, mantels have become less prominent, however, for many centuries they were frequently the most ornamental and artistic feature of the main room of a house. The mantel became the focus of decoration and was an opportunity for a sculptor or artisan to demonstrate their carving/craftwork skill, and for the architect or interior designer to use their creative flair to full effect depending on the style of the interior dcor, such as Classic, Renaissance, Italian, French, Victorian, Gothic, and so on.
In England, early-17th century mantelpieces were very simple and followed the Italian style, sometimes only consisting of the mantelpiece with classic architraves and shelf. In the late-17th century the architrave was omitted in favour of more decorative moulding.
In the 18th century, mantelpiece design was more influenced by French styles and became more elaborately decorative, often featuring carved wood.
Mantels can be made from a variety of materials such as marble, limestone, granite, or fine timber. They are often flat on top so that ornaments such as candlesticks, clocks or framed pictures can be arranged on them.
A car park is a designated area or building where cars and other vehicles can be parked and left temporarily. In the United States, it is referred to as a parking lot. Car parks are a common feature of the built environment, and often adjoin shopping centres, public buildings, schools, sports and entertainment venues, and so on.
There are different types of car park, and the design will be dependent on the required use, location, available space, potential revenue, security requirements, and so on. Some of the most common types of car park include:
Surface-level car park. - Multi-storey car park.
Multi-storey car park. - Underground car park.
Underground car park. - Typically, car parks are an area with a durable or semi-durable surface. As the surface is often impervious, car parks can result in water pollution due to limited or no facilities that are capable of handling water run-off.
Typically, car parks are an area with a durable or semi-durable surface. As the surface is often impervious, car parks can result in water pollution due to limited or no facilities that are capable of handling water run-off.
Depending on the floor area of the relevant building or facility requiring a car park, or the number of occupants, there may be a minimum number of parking spaces required by the planning permission.
Parking space measurements will differ according to layouts, e.g. parallel, herringbone, in-line, but standard specifications are as follows:
Car: 2.4 m x 4.8 m. - Light vans: 2.4 m x 5.5 m.
Light vans: 2.4 m x 5.5 m.
Rigid vehicles: 3.5 m x 14.0 m.
Articulated vehicles: 3.5 m x 18.5 m.
Coaches (60 seats): 3.5 m x 14.0 m.
Car parks should be designed with a boundary that is clearly-defined so that members of the public know that it is a private space. Clear demarcation, i.e. painted lines and signs, should be used to direct drivers and pedestrians to designated routes and to make them aware of any conditions of use, such as charges and penalties.
Boundary features that can be incorporated include: -
Hedges, dense vegetation, grass verge, flower beds, ditches.
High or low retaining walls. - Fencing or railings.
Fencing or railings. - Barriers.
Barriers. - Bollards.
Bollards. - Natural features, e.g. river, trees.
Natural features, e.g. river, trees.
Other buildings or structures. - Many car parks use boom gates to allow or prevent access which are activated either manually by a cashier in a booth, or by the car driver presenting or taking a ticket. More modern car parks can feature technology that checks the duration of stay, allows the location of vehicles, finds empty spaces, and so on.
Many car parks use boom gates to allow or prevent access which are activated either manually by a cashier in a booth, or by the car driver presenting or taking a ticket. More modern car parks can feature technology that checks the duration of stay, allows the location of vehicles, finds empty spaces, and so on.
Some car parks operate on a pay-and-display system, in which a ticket is purchased from a cashier or ticket machine and displayed in the vehicles front window. Parking enforcement officers then check for compliance.
It is common for entry and exit routes to a car park to be situated close together, although larger car parks may require more than one point of entry/exit. Height restrictors may be necessary to control the type of vehicles that use the facility. Where there is open access at ground floor level, security measures should be designed to prevent unauthorised access.
Vehicular flow around a car park can be controlled by techniques such as; staffed control points, CCTV, barrier access, flow points, passive or active signage and so on. Signage should be designed so that it is clearly visible and used to control, instruct or warn users. Signs are typically used to indicate entry and exit routes, one-way lane directions, the location of pay booths/machines, toilet facilities, lift/staircases, emergency help points, and so on.
Urban Design Guidelines for Victoria, published by the State of Victoria (Australia) in 2016, states: Car parking structures are buildings used solely for car parking or mixed with other uses, and may provide parking for residents, commercial tenants, shoppers and visitors. They can be constructed above or below ground. Car parking structures cater for both vehicle and pedestrian movement, however pedestrians may be required to share paths with vehicles to reach a lift or stairwell, which can be a safety hazard.
Traffic engineering is the use of engineering techniques to enable easy and safe movement on roadways. It involves the assessment of, and design of, optimal flows of traffic, encompassing factors such as road geometry, pavements, cycling infrastructure, road signs, road markings, traffic lights, and so on.
Traffic engineering forms part of the larger discipline of transport engineering, which also includes plane, boat, train and pedestrian traffic systems as well as roadways.
Traffic engineers ensure traffic volumes, lighting, signals, markings and signs work together to allow the most efficient and safest traffic flow, as well as making sure that speed limits are appropriate. On new road projects, they will project the traffic loads and patterns that will have to be accommodated, and ensure they are properly integrated with existing roads. On existing road projects, they may design alterations to accommodate changing traffic patterns or new developments.
A smart motorway is defined as a concept that utilises technologies and procedures to monitor and respond to fluctuating traffic conditions on our motorways. Smart motorways which are being currently designed and installed have evolved from several years of feedback, lessons learnt and improvements since their first deployment on the M42 motorway in 2006.
According to several studies the financial impacts of congestion on the strategic road network is estimated to cost 2 billion per year, an amount likely to increase further due to the predicted traffic growth up to 2035. The key aim of smart motorways is to reduce congestion and improve journey times by better managing the traffic using roadside technology infrastructure, associated control centres, systems and operational regimes.
Smart motorways support the economy by providing much needed capacity on the busiest motorways, while maintaining safety for motorists and those who work on the roads.
Other benefits of differing types of smart motorway operational regimes have included reductions in accidents and reduced impacts on the environment associated with emissions from stationary or slow moving vehicles.
Smart motorways function by adopting various operational regimes to meet scheme operational requirements including:
Controlled motorway - Variable mandatory speed limits are applied to all types of smart motorways. A mandatory speed restriction refers to the uses of a red ring speed restriction which is legally enforceable.
Variable mandatory speed limits are applied to all types of smart motorways. A mandatory speed restriction refers to the uses of a red ring speed restriction which is legally enforceable.
Traffic conditions are monitored using vehicle detection equipment installed in or adjacent to the motorway at strategic locations. The vehicle detection equipment is linked to a Motorway Incident Detection and Automatic Signalling (MIDAS) system which analyses the data and recognises two differing traffic conditions queuing traffic or congestion.
Queue protection and congestion monitoring algorithms within the MIDAS system recognise differing traffic conditions and automatically set appropriate signs and mandatory speed restrictions on signals to actively manage traffic conditions. Safety specific intervention is provided by the Queue Protection algorithm which protects the back of queuing traffic and congestion is managed by introducing reduced speed limits to increase traffic throughput.
Hard Shoulder Running (HSR) - Hard Shoulder Running uses the same systems, algorithms and mandatory signal settings as the controlled motorway operational regime in addition to actively managing the hard shoulder. This operational regime dynamically opens and closes the hard shoulder at peak periods to reduce congestion and increase capacity. This operational regime allows differing levels of automatic and manual intervention dependent on the traffic conditions.
Hard Shoulder Running uses the same systems, algorithms and mandatory signal settings as the controlled motorway operational regime in addition to actively managing the hard shoulder. This operational regime dynamically opens and closes the hard shoulder at peak periods to reduce congestion and increase capacity. This operational regime allows differing levels of automatic and manual intervention dependent on the traffic conditions.
All Lane Running (ALR) - Following lessons learnt, feedback, driver surveys and simulations, the Smart Motorways All Lanes Running concept was introduced. All Lanes Running schemes permanently convert the hard shoulder into an additional running lane whilst operating with all of the features, systems and signalling associated with controlled motorway schemes.
Following lessons learnt, feedback, driver surveys and simulations, the Smart Motorways All Lanes Running concept was introduced. All Lanes Running schemes permanently convert the hard shoulder into an additional running lane whilst operating with all of the features, systems and signalling associated with controlled motorway schemes.
The term kiss-and-ride refers to a drop-off point for car users at stations, airports and interchanges. Ie it is a place where car drivers can drop someone off so that they can take another form of transport.
Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
Road traffic management is a field of logistics that concerns the planning and control of traffic from one location to another. One of the main challenges of road traffic management is accommodating traffic in a safe and efficient way to reduce or eliminate accidents.
Most roadways include devices intended for traffic control, most of them involving direct communication with the road-user, such as signs, signals and pavement markings. These assist with navigation, assign right-of-way, areas of safe passage, indicate speed limits, provide instructions, advise of hazards, and so on. Other forms of traffic control include kerbs, rumble strips, median barriers, speed humps, and so on.
Intelligent transportation systems (ITS) are advanced applications that provide services relating to different modes of traffic management and the smarter use of transport networks. They are based on the transfer of information between transport systems to improved safety and performance, including traffic management systems, information systems, warning systems, vehicle-to-infrastructure communication and vehicle-to-vehicle communication.
Traffic signal controllers are electronic devices located at intersections that control the sequence of the lights. Along with computers, communications equipment, and detectors to count and measure traffic, these controllers are frequently grouped into one system allowing the control of large numbers of traffic signals at intersections approaches to expressways and motorways, and so on.
Within the field of ITS, advanced traffic management systems (ATMS) integrate technology with a top-down management perspective that improves vehicle traffic flow and safety. The top-down perspective is achieved from a Transportation Management Centre (TMC) which receives real-time data from cameras, speed sensors, and so on. This data is processed and may inform actions such as traffic re-routing or using dynamic message signs (DMS).
Active traffic management is a method of increasing peak capacity and making traffic flows more efficient and smooth-flowing on busy roadways. Common techniques include DMS, variable speed limits, hard-shoulder running, ramp-metering, and so on.
In the event of incidents occurring, the control centre operator and automatic systems can change signs to alert road users, inform emergency services, and open and close lanes to keep traffic flowing and minimise delays.
Traffic restraint, or calming uses traffic control devices to create impediments for traffic rather than increasing efficiency of movement. Devices often used include speed bumps, barricades, turning prohibitions, stop signs and raised pavement markers. It can also be used in conjunction with initiatives to increase bicycle and pedestrian traffic, such as lower speed limits, wider pavements, bike lanes, and so on.
The Traffic Management Act (2004) provides powers to reduce road traffic congestion in urban areas.
A cycle path (or cycling lane) is a section of roadway reserved for cyclists. These paths can also be used by electrically assisted pedal cycles (EAPCs) that comply with the electric bikes section of the Highway Code.
Cycle paths are designed to improve access for cyclists. Ideally, they can also promote cycling by providing a safe and pleasant experience.
Guidance - Guidance on cycle infrastructure design was published in October 2008, produced through a partnership of the Department for Transport, Scottish Executive and the Welsh Assembly. It includes detailed explanations of the suggested parameters for cycle path planning across the country.
Guidance on cycle infrastructure design was published in October 2008, produced through a partnership of the Department for Transport, Scottish Executive and the Welsh Assembly. It includes detailed explanations of the suggested parameters for cycle path planning across the country.
Before incorporating cycle lanes into urban plans, it is important to consider whether or not a cycle lane is truly beneficial. It is essential to take things like bus lanes, narrow roads and complex junctions into consideration during this planning stage.
Specifications - The recommended width of a cycle path between two lanes of traffic is at least 2 metres if traffic is moving at speeds higher than 40 mph. This width allows cyclists to overtake each other when caution is exercised. Two-way cycle paths do exist, although they are not common.
The recommended width of a cycle path between two lanes of traffic is at least 2 metres if traffic is moving at speeds higher than 40 mph. This width allows cyclists to overtake each other when caution is exercised. Two-way cycle paths do exist, although they are not common.
On roads with 30 mph speed limits, the path must be at least 1.5 metres wide. When lanes are less than 1.2 metres wide, cyclists should not use child-carrying trailers or ride tricycles.
If possible, cycle paths should be made more obvious through the use of coloured surface treatments in addition to distinct road markings (such as white lines and pictograms) and signage.
Cycle path identification - Cycle paths are designated by markings to restrict motorised vehicles and inform pedestrians. Cyclists are not required to use these paths, although use of the paths is recommended.
Cycle paths are designated by markings to restrict motorised vehicles and inform pedestrians. Cyclists are not required to use these paths, although use of the paths is recommended.
Unless pavements are marked as shared spaces, they should not be used by cyclists. In this instance, pedestrians have right of way and cyclists must yield to them.
Off-road paths and other path types - Off-road cycle paths are typically shared by cyclists and pedestrians. Bridleways can also be used by cyclists, but cyclists must give way to users on foot or on horseback.
Off-road cycle paths are typically shared by cyclists and pedestrians. Bridleways can also be used by cyclists, but cyclists must give way to users on foot or on horseback.
London cycling initiatives - In London, Cycleways (formerly known as Cycle Superhighways and Quietways) are being developed to connect communities, businesses and destinations across London in one cycle network. The goal of this initiative is to create 450 kilometres of Cycleways by 2024.
In London, Cycleways (formerly known as Cycle Superhighways and Quietways) are being developed to connect communities, businesses and destinations across London in one cycle network. The goal of this initiative is to create 450 kilometres of Cycleways by 2024.
Three London boroughs, Enfield, Kingston and Waltham Forest, have been given additional funding to improve cycle access by 2021.
On 19 March 2020, the London Cycling Campaign released its Climate Safe Streets report. This report outlines the city's plans to improve access for cyclists by creating 'a high-quality cycling network' and reducing carbon emissions caused by traditional motorised vehicles.
Cycling to combat obesity initiative - On 27 July 2020, the Government announced plans to tackle obesity, which has been linked with complications that can occur in people who contract COVID-19. The Government's strategy includes encouraging exercise by making it safer and easier to cycle and walk in areas there are no suitable paths or facilities.
On 27 July 2020, the Government announced plans to tackle obesity, which has been linked with complications that can occur in people who contract COVID-19. The Government's strategy includes encouraging exercise by making it safer and easier to cycle and walk in areas there are no suitable paths or facilities.
The initiative, which will cost 2bn, will include:
Installing more cycle racks and storage hangars. - Appointing a new inspectorate to oversee cycling infrastructure.
Appointing a new inspectorate to oversee cycling infrastructure.
Investing in long term cycling programmes. - Changing the Highway Code to improve safety for cyclists and pedestrians.
Changing the Highway Code to improve safety for cyclists and pedestrians.
Creating additional low traffic neighbourhoods and a zero-emission transport city centre.
Giving people access to bikes through GP prescriptions.
Setting up a national e-bike programme for cyclists who may require assistance.
Bike repair vouchers worth 50. -
The term 'bearing capacity' refers to the capacity of soil to support applied loads that are acting on it. In the construction industry, this typically relates to the capacity of soil to support building foundations, in which case, the bearing capacity can be calculated from the maximum average contact pressure between the foundation and the soil that would not produce shear failure.
Three modes of failure limit bearing capacity: -
General shear failure. - Local shear failure.
Local shear failure. - Punching shear failure.
Punching shear failure. - The ultimate bearing capacity of soil (qu) is the maximum pressure which can be supported without failure occurring.
The ultimate bearing capacity of soil (qu) is the maximum pressure which can be supported without failure occurring.
The net ultimate bearing capacity (qnu) does not take into consideration the over-burden pressure and can be calculated as:
qnu = qu - Ydf -
Where: -
Y = unit weight of soil - Df = foundation depth
Df = foundation depth - The net safe bearing capacity (qns) considers only shear failure, and can be calculated as:
The net safe bearing capacity (qns) considers only shear failure, and can be calculated as:
qns = qnu / F -
Where -
F = factor of safety. - The allowable bearing capacity (qs) is the ultimate bearing capacity divided by a factor of safety, and can be written as:
The allowable bearing capacity (qs) is the ultimate bearing capacity divided by a factor of safety, and can be written as:
qs = qu / F -
On particularly soft soil, significant settlement can occur without shear failure. In such instances, the maximum allowable settlement is used as the allowable capacity.
Karl von Terzaghi developed a theory for evaluating the ultimate bearing capacity of shallow foundations. His theory states that a shallow foundation is one where the depth is less than or equal to its width.
In structural engineering, the term 'stiffness' refers to the rigidity of a structural element. In general terms, this means the extent to which the element is able to resist deformation or deflection under the action of an applied force. In contrast, flexibility or pliability is a measure of how flexible a component is, i.e. the less stiff it is, the more flexible it is.
Youngs modulus (E - elastic modulus) is a measure of the stiffness of a material. This is a material constant, independent of the amount of material.
Increasing the stiffness or rigidity of a structural element reduces its deflection under load. This can be done by strengthening its section or increasing its size, but this will generally also increase its cost.
In a structure that is made up of many different structural elements, those elements will carry load proportionate to their relative stiffness. Therefore, the load an element will attract increases the stiffer it is.
In terms of physics, a moment is the product of a physical quantity and a certain distance, and is usually defined with respect to a fixed reference point. Generally, a moment can be produced by any physical quantity that is multiplied by distance, with commonly-used quantities including force, mass, electric charge, and so on.
The moment of force that acts on an object, known as torque, is a measure of its tendency to cause the object to rotate about a specific point or axis, and is the product of the force and its distance from the point or axis.
Moment (M) = force (F) x distance (d)
For a moment to develop, the force must act in such a manner that the object begins (or would begin) to twist; in other words, when the force does not have an equal and opposite force directly along the line of action. For example, if two people are stood on opposite sides of a door and both are pushing on it with an equal force then there is equilibrium. If one person stops pushing then there would be no opposing force and the person still pushing would have created a moment of force.
The fixed reference point is also known as the centre of moments. This can be the actual point about which rotation occurs due to the force, or the axis about which the force may be considered as causing rotation.
A bending moment (BM) is a measure of the bending effect that can occur when an external force is applied to a structural element. This concept is important in structural engineering as it is can be used to calculate where, and how much bending may occur when forces are applied.
Torsion is the state of strain in a material that has been twisted by an applied torque. It will occur whenever a structural element is subject to a twisting force.
Torsion can be seen in a circular-section rubber bar inscribed with rectangles and which is held at each end, with one hand twisting in relation to the other: the rectangles become skewed or distorted. The state of strain that has distorted the rectangles is called torsion and consists of pure shear. The torsion that exists in the rubber bar will try to make it revert to its original shape.
Torsion develops shear stresses and is equivalent to tension and compression at right angles. This can be seen when wringing a wet towel the water is squeezed out by torsion-induced compression.
Torsion is expressed in: - Pascal (Pa) the SI Unit for newtons/m2, or
Pascal (Pa) the SI Unit for newtons/m2, or
Pounds per square inch (psi). -
Racking is the term used for when buildings tilt as their structural components are forced out of plumb. This is most commonly caused by wind forces exerting horizontal pressure, but it can also be caused by seismic stress, thermal expansion or contraction, and so on.
A buildings resistance to racking is dependent on the general construction of the building as well as its size, shape and orientation to the prevailing winds.
To be able to resist the forces of high winds and safeguard against racking, a continuous load path is a construction method that secures a building from the roof to the foundation. This involves shear walls, fasteners (i.e. nails and screws), metal connectors, and framing materials. This method helps to redistribute the wind pressure from the exterior of the building to the frame and then down to the foundation.
NB Safety in the storage and handling of steel and other metal stock, second edition, published by the Health and Safety Executive (HSE) in August 2016, defines racking as: A skeleton framework of supports, of fixed or adjustable design, to support loads without the use of shelves.
In a beam that is flexing (or bending), the point where there is zero bending moment is called the point of contraflexure. At that point, the direction of bending changes its sign from positive to negative or from negative to positive. (It may also be thought of as a change from compression to tension or vice versa).
For this change to happen, it must pass through zero the point of contraflexure. On a bending moment diagram, it is the point at which the bending moment curve intersects with the zero line.
An analogy may be made with a speeding train travelling west on a single track. In order to reverse direction and travel east, it must decelerate, stop then accelerate in the opposite direction. The point it stops, even if momentary, is zero the neutral point, where it is not travelling.
Theoretically, when considering a structural member under load, such as a reinforced concrete beam, the point of zero bending moment would seem to suggest no reinforcement would be required. However, omitting reinforcement at that point is considered inadvisable as, in a real-life situation, it may be difficult to locate the exact point of contraflexure.
Lateral loads are live loads that are applied parallel to the ground; that is, they are horizontal forces acting on a structure. They are different to gravity loads for example which are vertical, downward forces.
The most common types are: -
Wind load. - Seismic load.
Seismic load. - Water and earth pressure.
Water and earth pressure. - Wind load may not be a significant concern for small, massive, low-level buildings, but becomes more importance with height, the use of lighter materials and the use of shapes that may affect the flow of air, typically roof forms.
Wind load may not be a significant concern for small, massive, low-level buildings, but becomes more importance with height, the use of lighter materials and the use of shapes that may affect the flow of air, typically roof forms.
Significant seismic loads can be imposed on a structure during an earthquake. They are likely to be relatively instantaneous loads compared to wind loads. Buildings in areas of seismic activity need to be carefully designed to ensure they do not fail if an earthquake should occur.
Water pressure tends to exert a lateral load which increases linearly with depth and is proportional to the liquid density. Similarly, earth pressure (such as settlement) can be applied against below-ground structures such as basement walls, retaining walls, and so on.
Lateral loads such as wind load, water and earth pressure have the potential to become an uplift force (an upward pressure applied to a structure that has the potential to raise it relative to its surroundings). For more information, see Uplift force.
Structures should be designed carefully with likely lateral loads in mind. A structural element that is typically used to resist lateral loads is a shear wall. In simple terms, lateral forces could push over parallel structural panels of a building were it not for perpendicular shear walls keeping them upright.
Similarly, bracing can be used to resist lateral loads. The beams and columns of a braced frame structure carry vertical loads, whilst the bracing carries the lateral loads.
Vibrations are the oscillatory motions that can be experienced by a building, usually through its floors. Vibrations are regular cyclic motions of a given frequency and amplitude, typically being vertical vibrations, although horizontal vibrations are possible.
The length of a wave vibration is measured from the beginning of one point on a wave to the same point on the next wave and is known as the frequency. This is expressed as Hertz (Hz). The height of a wave vibration is measured from the centre line and is known as the amplitude. This is expressed in metres. The larger the amplitude, the slower the wave is as it moves from peak to trough (oscillation).
The consequences of building vibrations are determined by the source of the motion, its duration, and the buildings construction and layout. They may include:
Presenting a nuisance to occupants. - Disturbing sensitive equipment.
Disturbing sensitive equipment. - Causing fixture and fittings damage
Causing fixture and fittings damage - Damaging structural integrity.
Damaging structural integrity. - The consequences will be .
The consequences will be . - Vibrations that affect buildings can be produced by a variety of sources and most are felt through the floor system. Vibrations can originate directly in the floor and then travel out from the source, or can be propagated through building members from other sorces that originate in the ground or outside the building.
Vibrations that affect buildings can be produced by a variety of sources and most are felt through the floor system. Vibrations can originate directly in the floor and then travel out from the source, or can be propagated through building members from other sorces that originate in the ground or outside the building.
Internal sources include: -
HVAC equipment. - Lift and conveyance systems.
Lift and conveyance systems. - Fluid pumping equipment.
Fluid pumping equipment. - Human activity, e.g. walking, dancing, aerobic exercises, etc.
Human activity, e.g. walking, dancing, aerobic exercises, etc.
External sources include: -
Seismic activity. - Road, rail, subway systems.
Road, rail, subway systems. - Industrial activities.
Industrial activities. - Construction activities, e.g. demolition works.
Construction activities, e.g. demolition works.
Wind buffeting. - As even very low amplitudes of vibration can be perceived by occupants, building designers must consider how to avoid nuisance being caused through vibration. They should also consider the structural strength to ensure it is enough to resist the peak dynamic forces acting on it. Structural members and their connections must be designed to resist such forces, and connections must be designed to ensure that fatigue does not occur due to repeated cyclic loading.
As even very low amplitudes of vibration can be perceived by occupants, building designers must consider how to avoid nuisance being caused through vibration. They should also consider the structural strength to ensure it is enough to resist the peak dynamic forces acting on it. Structural members and their connections must be designed to resist such forces, and connections must be designed to ensure that fatigue does not occur due to repeated cyclic loading.
Frequency and amplitude are taken into building designers calculations to determine where extra stiffness is required to dampen the vibration. Damping refers to the minimising of amplitude in a vibration or mechanical energy loss.
Anticipated usage of the floors is a critical consideration that should inform the concept design. Similarly, if a building is being constructed near a busy road or above a subway system, the foundations should be carefully detailed to accommodate the likely vibrations.
During the initial design of a building, the likelihood of perceptible vibration in sensitive spaces should be carefully assessed. This is particularly important for buildings that are designed with an unusual geometry or complicated structural systems. As the complexity of a structure increases, the impact of vibration becomes more difficult to accurately predict and effectively minimise.
It is important that building designers properly consider levels of acceptable vibration at the concept design stage as it can be very difficult, and costly, to modify an existing floor to reduce its susceptibility to vibration. Remediation may require major changes to the mass, stiffness or damping of the floor system.
Vibrations are sometimes dealt with most effectively at source. For instance, machinery-induced vibrations can be minimised by using isolating mounts or motion-arresting pads. An inexpensive approach is to increase the floor loading within the building. Weight can be placed under a raised floor to minimise movement from foot traffic for instance, and dissipate vibration.
NB A vibration dose value is defined in BS6472-1(2008) as a relationship that yields a consistent assessment of vibration which correlates well with subjective response. It is used to estimate the probability of adverse comment which might be expected from human beings experiencing vibration in buildings. Consideration is given to the time of day and use made of occupied space in buildings, whether residential, office or workshop.
A lintel is a structural horizontal support used to span an opening in a wall or between two vertical supports. It is frequently used over windows and doors, both of which represent vulnerable points in a building's structure. Lintels are generally used for load-bearing purposes, but they can also be decorative.
The most common materials for lintels are timber, steel and concrete.
Timber is low cost, readily available and can be easily cut to size on site. However, it is generally only suited to small openings with low loadings.
Precast concrete lintels are economical and provide robust support for structures such as masonry over door and window openings. They are able to accept a wide range of surface finishes.
Steel lintels are generally made from pre-galvanised steel which is cut and either roll-formed or pressed into the required shape. Steel has the advantage over concrete in that the lintels are usually lighter and are easier to handle on site. The lintel can be shaped so that it is not visible above the opening. Steel is also versatile and can be custom-produced according to the specific building requirement, whether arched, in a corner, forming a bay window, and so on.
In order to specify the type of lintel required, the nature of the load to be supported must be calculated. This includes both dead and imposed loads. Dead loads refer to the static mass of the building components such as floor coverings, roof tiles, masonry, and so on, whereas, imposed loads refer to the weight of furniture, fittings, people and so on.
Lintels must have adequate support at each end, and typically, the length of lintel for a masonry wall is calculated by measuring the total width of the structural opening, and adding 150 mm for end-bearings at each end. If lintels or end-bearings are inadequate specified, they can cause cracking in decorations, or in the structure itself, and ultimately can cause structural failure and collapse.
Lintels are also important in terms of their role in reducing heat loss from a building and the occurrence of damp and condensation. Lintels must be designed and constructed carefully to avoid thermal bridging (a direct connection between the inside and outside through elements that are more thermally conductive than the rest of the building envelope). This may include the creation of a cavity within the wall above the lintel, and the insertion of insulation.
Lintels may also need to incorporate a cavity tray or damp proof membrane to direct water within the wall or cavity to the outside through weep holes. Stop ends at either end of lintels prevent water flowing off the end of the lintel back into the cavity where it may dampen the inside wall.
Mullions are members that form vertical divisions between units of a window, door, screen or glass curtain wall. Together with horizontal members known as transoms they provide rigid support to glazing.
A mullion wall is a structural system whereby the load of the floor slab is taken by prefabricated panels around the perimeter.
They can be used for decorative purposes, or to allow the combination of smaller window units into larger compositions, or to provide structural support to an arch or lintel. They can also be used as an element in door frames to divide an opening and allow two separate doors to be accommodated by a single frame.
The use of mullions dates back to before the 10th century. As the use of glass for windows became widespread, so did the use of mullions, as they allow larger openings to be sub-divided into smaller windows which are technically easier to manufacture and less expensive.
They can be found in Armenian, Saxon and Islamic architecture. They became more commonly used to divide paired windows in Romanesque architecture, as well as open arcades. The use of stone mullions in Gothic architecture increased both in terms of size and complexity, as they were used both structurally and ornamentally, particularly in churches for stained glass windows.
Modern mullions are commonly made from materials such as timber, aluminium, steel and UPVC.
The word 'mullion' is also commonly used to describe vertical members between panes of glass within a window assembly (rather than between window units). These smaller members are sometimes referred to as 'muntins'.
The term perpend refers to the vertical joints between blocks or bricks that have been laid in a horizontal course to form a wall. Perpends are normally filled and sealed with mortar. The horizontal mortar joint in a wall construction is typically referred to as the bed joint.
Rather than being filled with mortar, perpends may also be left open to form weep holes or cavity ventilators. These provide openings that allow the drainage of moisture from within a wall construction and allow ventilating air to the back of a wall to help prevent mildew, dry rot and damp. They are generally formed by plastic inserts into the perpends, as these form a more uniform opening compared to simply leaving a void. See weep holes for more information.
A perpend stone is a long stone that extends between the inner and outer layers of a stone wall, tying the two layers together. The stone is dressed at both ends.
The term perpend may also be used more generally to refer to any brick or stone the longest dimension of which is perpendicular to the face of the wall. See bond stone.
The expression keeping the perpends is a term used to describe what happens when cross joints or transverse joints in brickwork are maintained in a perpendicular line.
A bollard is an item of street furniture comprising a vertical post fixed into the ground at intervals to prevent vehicle access or to keep vehicles from using the pavement. Bollards can be up to a 1m high but are usually shorter. The intervals between bollards usually allow the passage of pedestrians, prams, cyclists and so on, although they may prevent the passage of trolleys at airports, supermarkets and so on. They can also be used as traffic calming measures to narrow the available space for vehicles to pass through, thereby slowing them down.
With the rise of terrorism in recent years, bollards are more frequently used in city centres to prevent vehicle ramming attacks and ram-raiding.
Bollards are available in various materials (cast iron, steel, concrete, timber, plastic etc), styles and colours and they can also be decorated. Cast iron was a traditional favourite, often with the crest of the city or local authority emblazoned near the top. Plastic bollards (usually red) which sit on the surface are frequently used by highway contractors during road works to separate the worksite from the road. Illuminated bollards can also be seen on traffic islands to provide pedestrian protection and to direct traffic in the desired direction.
The bollard has maritime origins from the time when old cannons were secured (open ends facing upwards and two-thirds buried) into the quaysides to provide a mooring point for ships. When bollards were subsequently purpose-made in the 19th century, they were often designed to have a cannon shape to reference their origins.
Recent years have seen the use of hydraulically-operated rise-and-fall bollards which allow entry at certain times or to certain vehicles e.g fire engines or police cars. When not required, the bollard can be made to descend into a buried housing, leaving its top surface flush with the ground. It is raised as easily when required. A more simple version, often found in car parks, involves a hinged bollard that can be locked in the upright position to prevent access to a parking space, or laid flat on the ground to allow authorised vehicles to park.
A corridor is a form of hallway or gallery which is typically narrow in comparison to its lenght and acts as a passage connecting different parts of a building. A corridor often has entry points to rooms along it.
Despite being a normal feature of many modern buildings, corridors did not become common until the late-17th century, and were only first used widely in the 19th century. Prior to the use of corridors as a means of circulation, people would simply flow from one room into the next.
It has been theorised that the proliferation of corridors was driven to a certain extent by socio-economic factors and evolving moral attitudes. Corridors were a means of separating the occupants of a building, such as servants from those they served, inmates from the prison guards, workers from supervisors, and so on. They created privacy, in that it was no longer necessary to go through rooms, it was only necessary to go in to them.
Corridors also helped increase the efficiency with which people could move through buildings, while also turning rooms into a series of dead ends by separating circulation from destination.
The design of corridors is largely determined by the functions of the building. Hospital corridors will need to be wide enough to allow bi-directional flow of traffic, including beds and wheelchairs. Hotel corridors need to be robust enough for suitcase wheels, trolleys, and so on. Corridors may need access to natural light from windows, or be lit well artificially so as to avoid dark corners and allow easy circulation.
However, they can sometimes be soulless 'between' spaces, with no particular character or function, anonymous decoration, poor-quality artificial light and the feel of a prison offering nothing but a series of locked cell doors.
The worlds longest corridor is in RAF Mount Pleasant on the Falkland Islands. Nicknamed the Death Star Corridor, it is half a mile (800 m) long, and links the barracks, messes, and recreational/welfare areas of the station.
There are a number of statutory requirements for the design of corridors. Part M of the building regulations sets standards for circulation spaces so as to make them accessible, this includes required widths to allow circulation by people in wheelchairs. Part B of the building regulations sets standards for fire safety; corridors may form part of escape routes, with required minimum widths, and may be protected corridors, that is, corridors which are protected from fire in adjoining accommodation by fire-resisting construction.
Deflection in engineering terms is the degree to which an element of structure changes shape when a load is applied. The change may be a distance or an angle and can be either visible or invisible, depending on the load intensity, the shape of the component and the material from which it is made.
Deflection is a crucial consideration in the design of a structure and failure to apply due attention to it can be catastrophic.
Different types of load can cause deflections. These include point loads, uniformly distributed loads, wind loads, shear loads as well as ground pressure and earthquakes, to name but a few. When a load produces a deflection that is too great, the component may fail.
Components and structures that suffer deflection include, beams, columns, floors, walls, bridge decks, tunnel walls, dams and so on. San Franciscos Golden Gate Bridge can sway by as much as 4m laterally under strong winds.
Non-structural components can also deflect, for example cladding panels on a building may deflect inwards when subject to intense wind loading.
Given the possibility of structural failure, building codes usually determine what the maximum allowable deflection should be to ensure the safety of a buildings users and overall structural integrity. For a beam, this is usually expressed as a fraction of the span, eg the beams deflection should not be greater than 1/360th of the span; so, if the span is 5m, the deflection should not be greater than 13.9mm. This will usually be measured at the mid-point of the beam.
A structural element will deflect less under load if its stiffness or rigidity is increased. This can usually be achieved by strengthening its section or increasing its size; the latter may also increase its cost.
The material itself must also be considered. For example, because aluminium is around three times more flexible than steel, it is often designed for deflection rather than strength. In contrast, glass is relatively inflexible: even slight deflections in a steel frame could cause the glass to fracture.
A drain is a pipe that serves only one building as a means of conveying water and waste water away to a sewer.
A lateral drain is a section of pipe that is positioned outside the boundary of a building. It may be located under a public pavement or road and either connects to a neighbour's drain or connects directly to a public sewer. It can also be placed under a property in situations where the sewer is shared between neighbours.
A lateral drain is a length of public drain that connects with the drains from other buildings to become a sewer. A public lateral drain carries wastewater and excrement away from a multi-occupant property such as a caravan site or a block of flats.
In England and Wales, the arrangement for lateral drains changed on 1 October 2011. Lateral drains that had been previously connected to the public sewer before 1 July 2011 were transferred to the ownership of the local sewerage companies (generally water companies). According to the regulation (referred to as The private sewers transfer regulations), Lateral drains situated upstream of lengths of sewer which are on or under land opted-out of transfer by a Crown body, or which are owned by a railway undertaker (and therefore specifically excluded in the transfer regulations) are also transferred.
If a private pipe becomes blocked before it joins the public infrastructure, it is the owners responsibility - not the sewerage authority - to pay for repairs or replacements of the pipe. It is generally not the responsibility of the building occupant or owner to maintain a lateral drain. Sewerage companies are typically responsible for public lateral drains since they are usually connected to a sewer network that is maintained by a local water company. This company is permitted to enter a property if it is necessary to inspect or service the public lateral drain.
New or existing lateral drains can be adopted by a sewerage company under Section 102 of the Water Industry Act 1991 (for existing structures) or section 104 of the Water Industry Act 1991 (for new structures).
Those responsible for maintaining the lateral drain must agree to having this responsibility transferred to the sewerage company. Once an agreement has been reached, the sewerage company will then maintain the lateral drains at their own expense.
In its broadest sense, the term soffit can be used to refer to the underside of any construction element, such as an arch, architrave, or projecting cornice. However, most commonly it refers to the underside of the eaves, that is, the underside of the part of the roof that projects beyond the external wall of a building.
Typically soffit boards will be fixed to the underside of projecting rafters to form the soffit, whilst fascia boards are fixed along the vertical faces of the rafters forming a fascia. In combination, these elements help to seal the roof at its edges. However, they may include small openings to allow ventilation of the roof void, helping prevent the accumulation of moisture which could result in condensation and cause the roof to decay.
Soffits are traditionally constructed from timber, however, a wide range of other materials may also be used, including metal cladding, UPVC, vinyl and composite materials.
Inside buildings, the term soffit may refer to any portion of a ceiling that is lower than the rest of the ceiling. This can be used as an accent in rooms for decorative reasons, or in rooms with high ceilings to make the room feel smaller. They can also be required to conceal structural beams, plumbing elements, heating/cooling ducts or light fixtures.
In classical architecture, the soffit can be decorated with tooth-like blocks used in a close repeating pattern, known as dentils. In the Doric order, rectangular blocks were commonly hung from the soffit of the cornice over the triglyphs, known as mutules.
Whether in a house or apartment, a bedroom is usually a place reserved for sleeping (among other activities). Key furniture items usually found there include beds and bedding, chests of drawers, wardrobes and bedside tables.
The majority of bedrooms from the humble to the lavish tend to be simple affairs, a throwback perhaps to Victorian attitudes to sleeping accommodation which was widely thought should be kept simple for both hygienic and aesthetic reasons.
Today, most adults bedrooms contain a double bed whereas a childs bedroom will have one or more single beds, or perhaps even a bunk-bed if space is at a premium. Many adults and childrens bedrooms will also contain a TV.
The young persons bedroom is typically a multi-functional space that is more than just for sleeping: it also doubles up as a place for study and play. Given that most youngsters bedrooms will have a PC or laptop, the space may also function as a living room for the young person and their friends.
Historical development - The bedroom as it is known today developed from its early beginnings in Tudor times and resulted from the interplay of two key factors. The first was the introduction of brick-built chimneys brought about by the availability of locally produced bricks at a fraction of the price of stone. This in turn hastened the demise of the large, open-hearthed hall which had originated in medieval times. Introducing a brick chimney rising through the upper regions of the hall allowed short spans between external walls and the chimney. This allowed the creation of accommodation on the upper floor which could be carved up into sleeping quarters. The second prevailing factor at this time was the increasing taste for privacy. Therefore, bedrooms as we know them today have their origins in the late 14th century.
The bedroom as it is known today developed from its early beginnings in Tudor times and resulted from the interplay of two key factors. The first was the introduction of brick-built chimneys brought about by the availability of locally produced bricks at a fraction of the price of stone. This in turn hastened the demise of the large, open-hearthed hall which had originated in medieval times. Introducing a brick chimney rising through the upper regions of the hall allowed short spans between external walls and the chimney. This allowed the creation of accommodation on the upper floor which could be carved up into sleeping quarters. The second prevailing factor at this time was the increasing taste for privacy. Therefore, bedrooms as we know them today have their origins in the late 14th century.
The tradition of having bedrooms on the upper floors of houses continued right through Georgian, Victorian and Edwardian periods, through to the modern day.
Bedroom design - There are a few key rules to bear in mind when designing bedrooms, if they are to be fit for purpose.
There are a few key rules to bear in mind when designing bedrooms, if they are to be fit for purpose.
A double-bedroom needs to be able to accommodate either a double bed or, as an alternative arrangement, two single beds. There must also be space for a wardrobe (freestanding or in the form of a built-in cupboard) that is a minimum of 550mm deep, with 600mm of running space per person. There should also be a chest of drawers and a bedside table. For multiple-occupancy bedrooms, there should be sufficient space for a single bed and a bedside table for each occupant.
Beds require space around them for making: for a 900mm-wide single bed, a minimum width of 350-400mm should be allowed for on one side at least. Whereas for a 1500mm-wide double bed it is advisable to ensure a 700mm-wide minimum access on either side of the bed.
Given the plethora of available electrical goods that can be used in a bedroom bedside lamp, clock radio, hairdryer, vacuum cleaners etc, it is advisable to ensure the correct provision of electrical outlets. Currently, it is considered that a main bedroom should have three double-socket outlets, with two seen as the minimum. Single bedrooms are usually provided with two double outlets. Study bedrooms should have a minimum of two while single bedsit rooms ideally should have three double-sockets to accommodate the additional requirements of cooking, washing etc.
In the UK, the provision of bedrooms in a dwelling is the main indicator of size and is thus an important yardstick of measurement and the available space. A one-bedroom home is more likely to be a flat than a house, while a four-, five- or six-bedroomed dwelling is almost certainly likely to be a house. In continental Europe, the yardstick of a dwellings size is usually given by square metres of floorspace rather than number of bedrooms.
Culvert, screen and outfall manual, (CIRIA C786)published byCIRIAin 2019, definesair draughtas the: Vertical gap between thewatersurface and theroof(soffit) of aculvertoroutfallto allow forfloatingdebris (also known asheadroom).
Anaqueductis a channel that has beenconstructedfor the specific purpose of carryingwaterfrom onepointto another. The source and distributionpointmay be a significant distance apart, and thewateris often transported over an elevatedmasonryorbrickstructure- often in theformof abridge- supported onarches. It can also be carried through a series oftunnelsor otherundergroundsystems.
Before being adopted by engineers of the Roman empire, this ancient water delivery system had already appeared on a small scale in many different parts of the world including Greece, Egypt, Jordan, Persia, Oman, India and the Americas. These aqueducts were primarily used to supply irrigation systems for farming purposes, but the waterways also provided bathing and drinking water to some parts of the population.
With the rise of the Roman empire, cities expanded rapidly, triggering a need for suitable infrastructure to support the population. This included the reliable delivery of water.
Some of the earliest Roman aqueducts date back to the fourth century BC. The first of these structures, the Aqua Appia, was used to supply water from approximately 10 miles outside of the city. This aqueduct was mostly underground until it reached the edge of the city. At this point, it emptied into a series of reservoirs that distributed water to different parts of the city.
The need for fresh water drove the construction of complex aqueducts. These used the basic properties of gravity and the construction of a series of channels that gradually declined over significant distances (sometimes of 50 miles or more). A steeper gradient allows a smaller channel to carry the same amount of water as a larger channel with a lower gradient, but it must start from a higher point to reach the same distance.
Attenuation refers to a reduction inforce, effect, orvalue. Attenuation may be achieved by anattenuator.
The SuDS Manual published by CIRIA in 2015 defines attenuation as: Reduction of peak flow rate and increased duration of a flow event. It defines attenuation storage as: Volume in which runoff is stored when the inflow to the storage is greater than the controlled outflow.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines attenuation as the: Reduction in the peak discharge of a flood as it passes down river due to storage or constrictions.
The term attenuation is also used in the construction industry to refer to the reduction of the transmission of sound, typically in ductwork, doors or other elements that pass from one area to another. It can also refer to wave attenuators, pressure attenuators in ventilation piping and so on.
Culvert, screen and outfall manual, (CIRIA C786)published byCIRIAin 2019, definesbankfullas: A situation where thewaterlevelin thewatercourseequates to the top of the river-bank, at theleveljust beforeoverflowingoccurs.
Culvert, screen and outfall manual, (CIRIA C786)published byCIRIAin 2019, definesbackflowas: Flow in aculvertordrainin the opposite direction to the normal flow direction as a result of a high downstreamwaterlevel(most often experienced in tidalwaters.
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published byBSRIAinpartnershipwith theClosed Systems Control Association(CSCA) in March 2021, defines abiocideas: A chemicalagentwhich either kills or prevents the multiplication of organisms inwatersystems.
TheSuDS Manualpublished byCIRIAin 2015 defines abermas: A shelf or raisedbarrierseparating twoareas.
Groynes in coastal engineering (CIRIA C793), published by CIRIA in 2020, defines a berm as: A ridge located to the rear of a beach, immediately above mean high water. It is marked by a break of slope at the seaward edge.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines bedload as: Sediment load in a channel that travels by rolling, sliding or bouncing along the bed.
Ablue roofis aroofdesigned for theretentionofrainwaterabove thewaterproofingelementof theroof. This is as opposed to more conventionalroofswhich allow forrainwatertodrainfrom theroof.Blue roofsare typicallyflat, without any fall, with control devices regulatedrainageoutlets that enablewaterto be retained or drained.
The SuDS Manual published by CIRIA in 2015 suggests that a blue roof is: A roof construction that stores water, can include open water surfaces, storage within or beneath a porous media or modular surface or below a raised decking surface or cover.
Some of the reasons for incorporating a blue roof into a building, include:
As a form of Sustainable Urban Drainage System (SuDS) to try and alleviate urban flooding caused by stormwater run-off.
In areas of urban density, the space created by a blue roof can avoid having to provide attenuation for rainwater at ground level.
Rainwater harvesting for use, independent from, or supplemental to the mains water supply, such as wc flushing or green roof irrigation
Cooling solar panels, or reducing load on mechanical refrigeration or cooling equipment.
For recreational purposes, such as rooftop swimming pools or water features.
Unlike some other forms of SuDS, blue roofs make use of spaces that might otherwise be redundant without extending beyond the footprint of the building or into ground space which, depending on the density of the location, may be expensive.
TheSuDS Manualpublished byCIRIAin 2015 suggests that ablue spaceis: Similar togreen space, but it is anareaofwaterrather than vegetation.
Where a green space is: An area of grass, trees or other vegetation set apart for recreational or aesthetic purposes in an otherwise urban environment.'
Culvert, screen and outfall manual, (CIRIA C786)published byCIRIAin 2019, defines aboulder trapas: Acourse screenwith widely-spaced bars or settlingbasindesigned to trap largesedimentrolling along thewatercourseasbed load, and to allow the remainingwaterandfloatingdebris tooverflow.
Technical paper 35: Moisture measurement in the historic environment, published byHistoric EnvironmentScotlandin 2021, definesbound wateras: Atype of waterwhich is not easily mobilised, since it is an intrinsiccomponentof a molecule such as a mineral.'
Culvert, screen and outfall manual, (CIRIA C786)published byCIRIAin 2019, definesbracingas: Additional strengthening provided for longscreen barsthat might otherwise be bentin useor as a result of vandalism.Bracingshould be recessed so that it does not interfere with movement of cleaning rake.
Groynes in coastal engineering (CIRIA C793), published byCIRIAin 2020, defines abreakwateras: Astructureprojecting into the sea thatsheltersvessels from waves and currents, prevents siltation of navigation channel, protects a shorearea, prevents thermal mixing (for example,cooling waterintakes) or has a recreational purpose. Inbeach management,breakwatersare generallystructuresprotectingareasfrom the full effect of breaking waves.Breakwatersmay be shore attached and extended seawards from thebeach, or may bedetachedand sitedoffshore, generally parallel to thebeach, to provide shelteredconditions.
Waterproofingis a process that ensures astructureor object is able to keep out 100% of anywaterthat comes into contact with it. Inconstruction,waterproofingcan increase thelifeofcommonmaterialslikeconcrete,iron,paintand more. Although it is notcommonto refer to abuildingas being 'waterproof' (although it would not be wrong and would be understood by most), it is morecommonto use the term watertight or 'weatherproof'.
It defines shore-parallel breakwaters as: Shoreline erosion control structures placed parallel to the coast to reduce the wave energy attacking the coastline.
A caisson is a box-like structure commonly used in civil engineering projects where work is being carried out in areas submerged in water.
The SuDS Manual published by CIRIA in 2015 defines a 'catchment' as: 'The area contributing surface water flow to a point on a drainage or river system. Can be divided into sub-catchments.'
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines catchment as: The area of land that drains to a given point on a river, drainage system or other body of water.
It defines a flashy catchment as: A catchment with a watercourse that rises immediately following a period of rain.
NB In relation to human geography, a catchment area is the area from which a city, service, institution etc. attracts the population that it serves.
The SuDS Manual published by CIRIA in 2015 defines a catchpit as: A small chamber incorporating a sediment collection sump that the runoff flows through.
A cesspool is an underground tank used to collect wastewater and sewage. It will typically have a manhole for access, but does not have an outlet and does not discharge any of its contents. Unlike a septic tank, a cesspool does not process or treat wastewater and sewage it simply stores it.
Cesspools are sometimes referred to as cesspits, although both terms can also be used to refer to a underground chamber that is not sealed at the bottom so as to allow liquid to seep into the surrounding ground (commonly referred to as a soak pit). This has not been permitted since the introduction of the Public Health Act 1936.
Cesspools should be inspected fortnightly and the level checked (an automatic alarm may be installed). The contents of the cesspool must be removed regularly (typically every month depending on size and usage much more frequently than an equivalent septic tank) by a licensed waste handler using a vacuum tanker. This can be a significant expense.
Cesspools are generally only installed at properties that are not connected to the public sewer network and that do not have suitable ground to provide a septic drain field (required for the installation of a septic tank), or at locations such as campsites where chemical toilets are emptied that might prevent a septic tank from functioning correctly.
Permits are not required for cesspools, and they do not have to comply with the general binding rules that apply to septic tanks. However, planning permission and building regulations approval is needed to install a cesspool.
Requirements for the design, construction and maintenance of cesspools are set out in Approved Document H of the building regulations, which permits cesspools were the installation of a septic tank is not reasonably practicable.
Cesspools should be at least 7m from habitable parts of a building, preferably downslope, and must be adequately ventilated. They should be within 30m of vehiclular access. They should have a capacity of at least 18,000 litres for two users and a further 6,800 litres for each additional user. A filling rate of 150 litres per person per day is assumed when estimating filling rates.
A durable notice must be fixed in the building associated with the cesspool, providing information about its maintenance.
Cesspools are generally manufactured from glass reinforced plastic, polyethylene or steel, or constructed from brickwork or concrete. Older cesspools of masonry construction may have deteriorated over time, resulting in leaks or weaknesses that can lead to collapse. Cesspools should be inspected periodically by a suitably qualified engineer to ensure they remain sound.
If a cesspool does not fill as quickly as expected, or if the level suddenly drops, it should be inspected for possible leaks. Allowing a cesspool to overflow or leak is an offence under the Public Health Act 1936, and allowing a cesspool to pollute a watercourse is an offence under the Water Recourses Act 1991.
Biodiversity in new housing developments: creating wildlife-friendly communities, published by the NHBC Foundation in April 2021 defines a check dam as: A small barrier within a swale or rill to slow flows, control erosion and trap sediment. They may be constructed from large stones or logs or other material.
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published by BSRIA in partnership with the Closed Systems Control Association (CSCA) in March 2021, defines a chelant or chelating agent as: An organic compound causing a substance which would normally be insoluble to be held in solution or to pass into solution.
Chilled water is commonly used in buildings to provide cooling.
Typically, water is cooled in chiller units, and is then distributed by pipework to air handling units where it is used to cool air that is ducted through the building for ventilation. It can also be used for the dehumidification of ventilation air. As the temperature of air falls, it is less able to 'hold' moisture, that is, its saturation water vapour density falls, and moisture will begin to condense, dehumidifying the air. See Air conditioning for more information.
Chilled water may also be used to provide cooling to integrated service modules, chilled beams, chilled ceilings, underfloor cooling, for industrial processes and so on. The use of chilled water to cool the building fabric (rather than ventilation air) is sometimes described as 'active thermal mass'.
The 2018 International Residential Code (IRC), published by the International Code Council (ICC) defines a cleanout as. An opening in the drainage system used for the removal of possible obstruction and located to allow for access.
Despite occupying less than 15% of the Earths land surface,
coastal zones accommodate more than 40% of the worlds population. Historically, this is due to the increased commercial and industrial potential of areas that are near the coast, such as shipping, fishing and tourism industries.
Coastal defences are a key part of coastal management, in which the land-sea boundary is protected from flooding and erosion, categorised as hard engineering and soft engineering.
Cofferdams are temporary structures used where construction is being carried out in areas submerged in water. They are most commonly used to facilitate the construction or repair of dams, piers and bridges. The aim of a cofferdam is to be as watertight as possible to create a dry area in which to complete the required building works, or at least to limit water ingress to a safe level that can be pumped away.
Cofferdams must be able to withstand very high pressures and can create a hazardous situation if they are installed incorrectly. They are usually constructed using steel sheet piles driven into the ground and supported by internal braces and cross braces. Timber sheet piles, concrete or a combination of materials can also be used.
A cofferdam can be any shape. Its design will be depend on the depth required, the required working area, soil conditions, fluctuations in the water level, and so on.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines a conduit as: A channel or pipe for conveying water or other fluid. A culvert would normally be a buried conduit and a channel an open channel conduit.
The word conduit may also refer to electrical conduits, which are tubes or pipes used to protect and route electrical wiring as it passes around buildings or other structures. This is generally made from either metal or plastic, and may be rigid or flexible.
Firestopping of service penetrations, Best practice in design and installation, published by FIS (Finishes and Interiors Sector) in 2020, defines a conduit as: A metal or plastic casing designed to accommodate cables, normally circular in section.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines a control structure as: A hydraulic structure with a known relationship between water level (stage) and discharge (or flow rate).
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines cutwater (or bullnose) as a: Shaped projection on a pier or dividing wall between culverts to help division of flow and to deflect debris.
Dams are barriers, usually constructed across rivers, to hold back and contain water in a lake or reservoir. Dams are usually built using concrete, or natural materials such as earth and rock, and in cases such as the Hoover Dam and the Three Gorges, are major engineering projects with a construction programme lasting many years.
For centuries, dams have been a vital part of the water infrastructure, serving many different purposes, including:
Water supply: Reservoirs store rainwater before it is filtered and processed for human use.
Hydroelectric power: Reservoirs store rainwater to be used in hydroelectric power stations to generate electricity.
Flood control: Reservoirs control water flow into rivers after heavy rain.
Irrigation: Water can be stored in reservoirs for irrigating land during dry periods.
Navigation: Dams can be used to raise the upstream water level to improve navigation conditions.
A culvert is: 'A covered channel or pipe which prevents the obstruction of a watercourse or drainage path by an artificial construction.' The term 'de-culverting, sometimes referred to as 'daylighting' refers to: 'The removal of a culvert to restore a watercourse to a more natural state.' Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
A culvert is a closed conduit or tunnel used to convey water from one area to another, normally from one side of a road to the other side.
Typically culverts are box shaped, round or elliptical in cross section. They are often pre-fabricated and can be made from pipes, reinforced concrete or other materials that are embedded within the surrounding landscape to create a bridge-like structure that permits the stable and proper flow of water under an obstacle such as a road, and can help alleviate flooding and reduce erosion.
Culverts can also be used to move rainwater runoff along, under or away from highways.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines design flood as: The discharge or flow adopted for design, usually defined in terms of return period or annual exceedance probability.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines desilting as: Removal of sediment accumulated on the natural or design bed level of a channel or culvert, generally as a maintenance activity.
'Detention ponds are used to attenuate the flow from a drainage system, to limit the peak rate of flow into a sewer system or watercourse. Further information on design may be found in the references given in paragraph 3.36 and in Sustainable Urban Drainage Systems A Design Manual for England and Wales published by CIRIA.' (This has been superseded by The SUDS manual (2011 reprint with errata), 2007).
Drainage is the artificial removal of water, both surface and sub-surface. Drainage is often a major element of civil engineering and construction projects and is necessary to avoid flooding and other damage.
A drain is a pipe that serves only one building as a means of conveying water and waste water away to a sewer.
A lateral drain is a section of drain positioned outside the boundary of a building, connecting with the drains from other buildings to become a sewer.
Drains within the boundary of a building are the responsibility of the owner (unless the drains of other properties run through their property), including liability for any maintenance and repairs. Insurance can be taken out to cover work on private drains.
Dredging is the process of excavating and removing sediments and debris from below water level, typically from the bottom of lakes, rivers, harbours, and so on. Dredging is generally necessary because of sedimentation which is the process in which sand and silt washes downstream and accumulates over time in channels and harbours.
Dredging may be carried out for a number of reasons:
To increase the depth of the bed to allow boats and ships to pass through.
To obtain aggregates for manufacturing concrete. - To obtain other materials for use in civil engineering projects.
To obtain other materials for use in civil engineering projects.
To excavate trenches for laying pipelines, cables, and so on.
To increase channel capacity, thereby helping with flood prevention.
To prevent the spread of contaminated sediments to other areas of the water body.
For land reclamation. This is the process of forming areas of land by depositing dredged materials and building them up. One of the most famous projects of this kind was the construction of the Kansai International Airport in Japan, which involved the building of an artificial island in the middle of Osaka Bay.
As an engineering term, a dyke is a form of flood protection designed to keep seawater or river water from overrunning land that is adjacent to it. Dykes are usually permanent structures that are built in areas that are located below sea level and are thus uninhabitable. Their placement reclaims land to make it fit for use.
In certain situations, temporary dykes can be built to divert water from areas that have been disturbed as a result of natural or human activity. These structures direct water to a more suitable location. They can also help to reduce the flow of water to control issues associated with erosion.
The word emulsify refers to: The mixing of two or more liquids that are normally immiscible (non-mixable or un-blendable). Ref Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014.
This produces an emulsion, which is a fine dispersion of droplets of one liquid in the other. Emulsions are used to manufacture polymer dispersions which can be used to produce paints, glues, synthetic rubber and synthetic latex.
An elevated building, with regards to flooding, is a building that is raised on columns (or stilts) so that the floor level is higher than the potential level of the flood water. This is a simple and logical way to protect a property from flooding but it is reliant on accurate predictions of flood levels.
Elevated buildings maybe constructed from many different materials, such as brick, concrete, steel and wood. The actual construction materials used may be influenced by the local vernacular or may be determined by the flood hazard. Deep and/or fast flowing water can be a hazard to buildings. In some cases the structure required to resist the hydrostatic pressure can be considerable.
Electrical resistance meters measure dampness either on the surface, or within the building fabric itself. Generally, if the meter reading indicates that the fabric is dry, then it is dry.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines erosion as: Removal of particles from the substrate by wind, flowing water or wave action (opposite is accretion).
Groynes in coastal engineering (CIRIA C793), published by CIRIA in 2020, defines erosion as the: Removal of the land or beach by the combined action of the motion of water and sediment. For the beach this can lead to beach retreat and/or beach lowering.
Evaporation is: Vaporisation of a liquid that occurs from the surface of a liquid into the gaseous phase.
Biodiversity in new housing developments: creating wildlife-friendly communities, published by the NHBC Foundation in April 2021 defines evapotranspiration as: The combined effect of evaporation and transpiration by the foliage of plants. Assists in cooling the local atmosphere.
Biodiversity in new housing developments: creating wildlife-friendly communities, published by theNHBCFoundationin April 2021 defines afilter stripas: A strip of grass collectingsiltandsedimentsand slowingrun-offflow from hard surfaces. They are often used in conjunction withswales.
Firefighting water is: Water used to cool, extinguish or prevent the spread of fire during an incident. It is likely to become contaminated with product and firefighting foam as a consequence of its use in firefighting activities. Water that is used solely to cool storage tanks water sprays or deluge systems (often described as cooling water) is less likely to become contaminated with product.
Guidance on the code of practice for property flood resilience, published by CIRIA in 2021, defines a flash flood as: Rapid flooding of an area of land because of intense or extreme rainfall events or failure of infrastructure designed to store or carry water or protect against flooding (distinguished from general flooding by the sudden onset).
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published by BSRIA in partnership with the Closed Systems Control Association (CSCA) in March 2021, defines a flocculant or flocculating agent as a: High molecular weight polymer that encourages particles to agglomerate. Sometimes used as an aid for cleaning and flushing.
Code of practice for property flood resilience, Edition 2, published by CIRIA in 2020, defines a flood map for planning as: A map for land-use planning and development purposes, showing what flood zone (under National Planning Policy Framework (MHCLG, 2019) definitions) a proposed development is in.
Guidance on the code of practice for property flood resilience, published by CIRIA in 2021, defines flood resilience as: The combination of flood resistance and flood recoverability.
It defines flood resilience technologies as: practical devices and techniques which improve the resilience of buildings to flooding.
Code of practice for property flood resilience, Edition 2, published by CIRIA in 2020, defines property flood resilience as: Flood resilience related to buildings within the curtilage of a property.
A floodplain is land adjacent to a watercourse over which water flows or would flow in times of flood, if defences were not in place.
The flood zone area classification system devised by the Environment Agency refers to:
Flood Zone 1: Land outside the floodplain. There is little or no risk of flooding in this zone.
Flood Zone 2: The area of the floodplain where there is a low to medium flood risk.
Flood Zone 3: The area of the floodplain where there is a high risk of flooding.
Floodscapes, Contemporary Landscape Strategies in Times of Climate Change, was published by nai010 publishers in March 2021. It was written by Frdric Rossano with support from the French Ministry of Culture and Communication, Bureau of Architectural, Urban and Landscape Research (BRAUP) and AMUP Research Laboratory.
It defines a floodscape as the visible, tangible, and acceptable changes that occur to topography when a flood temporarily erases previously established forms and features from the visible landscape. Acknowledging the inevitability of floodscapes and embracing their impact is seen by Rossano as a more practical method of adapting to nature rather than fighting against it as long as safety is maintained and risk is minimised.
A fountain is an architectural feature which involves water and is often used as part of landscaping. A fountain can either pour water into a basin to create a waterfall effect or spray water into the air to create a jet effect. Fountains are often used as decorative features in public spaces and gardens.
Drinking fountains are used to provide drinking water public spaces, and special musical fountains combine lights, music and moving water jets for purposes of entertainment. Splash fountains are often used in public spaces and intended for interaction.
The earliest fountains, in Ancient Rome, were functional and used for providing water for drinking and washing. For a water flow to be consistent it required a source (e.g. reservoir or aqueduct) that was higher than the fountain and so was reliant on gravity.
By the end of the 19th century, fountains had been replaced as the main source of drinking water by domestic plumbing and so became primarily decorative. At around this time, gravity was replaced by mechanical pumps which enabled fountains to recycle water and project it into the air. At the start of the 20th century, fountains began to adopt steam pumps and then later on electric pumps to receive water from the source.
Modern fountains rely on a closed recirculating system to recycle water. An electric pump is used to provide the power to push water through the pipes. The pump is typically submerged in the water reservoir and consists of a spinning impellor to draw water in and force it out by centrifugal force. The most appropriate pumping rate will need to be found as the fountain can splash and waste water if it is set too high and will not circulate at all if it is set too low.
Water is delivered to the fountain head and then sprayed into the air through a nozzle or left to flow outside the fountain. In both cases the water will fall back onto the fountain and drain back into the reservoir. Larger fountains will often be fitted with multiple nozzles and pumps.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines freeboard as: An allowance for uncertainty in design water level and any other physical processes that may affect the ability of an asset to withstand the design water level such as wave action or superelevation.
Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014 defines freeboard as: An allowance in the form of increased height of a containment wall for additional capacity over and above the minimum design requirement.
Geomorphology is: The scientific study of the evolution and configuration of landforms. Also known as fluvial geomorphology.
A geomorpholocial assessment, sometimes referred to as a fluvial audit is: The establishment of baseline hydromorphological form and behaviour for a river reach in the context of conditions prevailing in the wider river network and catchment as a whole.'
Green roofs are roofs that are purposely fitted or cultivated with vegetation. They are also be known as living roofs, eco-roofs or vegetated roofs (CIBSE 2007).
It is generally accepted that there are two main types of green roof which are described by Kibert (2008) as:
'Extensive: Extensive landscaped roofs are defined as low maintenance, drought-tolerant, self-seeding vegetated roof covers that incorporate colourful sedums, grasses, mosses, and meadow flowers that require little or no irrigation, fertilisation, or maintenance Extensive systems can be placed on low-slope and pitched roofs with up to a 40% slope.
Intensive: If there is adequate load-bearing capacity, it is possible to create actual roof gardens on many buildings. This type of eco-roof system may include lawns, meadows, bushes, trees, ponds, and terraced surfaces. Intensive systems are far more complex and heavy than extensive eco-roof systems and hence require far more maintenance.'
Some authors also describe a third type of green roof as 'simple intensive' which usually comprise grasses, herbaceous plants and shrubs. Simple intensive green roofs can be constructed using varying depths of substrate, thus combining elements of extensive and intensive roofs (Newton, Gedge et al. 2007).
Extensive green roofs are the most popularly deployed forms of green roofs as they are generally light weight and low cost.
Hard landscape (also referred to as hardscape) is a term used to describe the non-plant material used in landscaping, such as a park or garden. The term is most commonly used by landscape architects and other professional garden designers who have been hired to enhance a landscape.
A headwall is: The retaining wall at a culvert inlet or outlet that provides support to the embankment. The headwall is normally at right angles to the culvert barrel, but may be skewed. The headwall may have wingwalls at an angle to the headwall that provide support to the channel sides and form part of the transition from channel to culvert and vice-versa.
The term hydraulic jump refers to an: Abrupt rise in water level when flow changes from supercritical to subcritical, accompanied by surface disturbance and air entrainment and an associated dissipation of energy.
The term hydraulic pressure refers to: The pressure exerted by water (whether at rest or moving) on a surface or structure. Hydraulic pressure has the units of force per unit area and is calculated for water at rest as the product of the depth of water and its density. The pressure can differ for water in motion. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
Hydraulic pressure can also refer to the pressure exerted by other liquids, such as those used in mechanical equipment sometimes referred to as hydraulic fluids.
The term hydraulics refers to the technology and science relating to the mechanical properties and use of liquids.
Hydromorphology relates to: The shape and physical characteristics of rivers, estuaries and open coastlines.
Hydromorphological is a: Term used in Directive 2000/60/EC (Water Framework Directive, WFD) for elements describing the form (morphology) and functioning (flow and sediment regime) of surface waters including rivers. Elements include width, depth, variability and connectivity. These elements drive habitat availability and quality.
The term hydrostatic pressure refers to: The pressure exerted by water at rest. Ref Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019.
The hyphoreic zone is the: Region of sediment and porous space beneath and alongside a stream bed, where there is mixing of shallow groundwater and surface water.
A lagoon is: An excavated area able to retain liquids as a consequence of the excavated area being below the level of the surrounding area, rather than being retained within a raised area.'
A lateral drain is a section of pipe that is positioned outside the boundary of a building. It may be located under a public pavement or road and either connects to a neighbour's drain or connects directly to a public sewer. It can also be placed under a property in situations where the sewer is shared between neighbours.
A lateral drain is a length of public drain that connects with the drains from other buildings to become a sewer. A public lateral drain carries wastewater and excrement away from a multi-occupant property such as a caravan site or a block of flats.
Leaching is: The removal of soluble or other constituents from a substance by the action of a percolating liquid.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines overtopping is: The passage of water over a component such as a floodbank or seawall, due to wave action. Overtopping does not necessarily represent failure of a flood defence to perform its function.
Groynes in coastal engineering (CIRIA C793), published by CIRIA in 2020, defines overtopping as: Water carried over the top of a coastal defence due to wave run-up exceeding the crest height.
It defines overwashing as: 'The effect of waves overtopping a coastal defence, often carrying sediment landwards which is then lost to the beach system.'
A manhole, also known as an inspection chamber, provides access to underground utilities, most commonly sewer systems. This enables operatives to undertake inspections, make modifications, and carry out cleaning and maintenance.
A manhole usually consists of a chamber or ring a vertical circular pipe of varying sizes and depths, which is used to access inspection points.
Manholes are generally constructed where there is a change of direction and/or a change in gradient of the utilities, or where access is required for a specific maintenance purpose. They are typically positioned 0.5 m away from curb lines, preferably with the manhole cover positioned away from the wheel line of traffic.
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published by BSRIA in partnership with the Closed Systems Control Association (CSCA) in March 2021, defines millscale as: A surface layer of iron oxides (mostly Fe3O4) formed during the manufacture of mild steel pipes.
A measure of the ease with which a fluid can flow through a porous medium. It depends on the physical properties of the medium, for example grain size, porosity and pore shape.
Bradford City Centre Design Guide, Supplementary Planning Document, published in 2006, suggests that permeability is: 'The ease with which people can move around an urban area. A permeable neighbourhood has plenty of streets and it is possible to move through the area by a variety of routes.'
Urban Design Guidelines for Victoria, published by The State of Victoria Department of Environment, Land, Water and Planning in 2017, suggest that permeability is: The extent to which the urban structure permits, or restricts, movement of people or vehicles through an area, and the capacity of the area network to carry people or vehicles.
The SuDS Manual (C753) published by CIRIA in 2015, defines a photolysis as: The breakdown of surface-held organic pollutants by exposure to ultraviolet light.
The SuDS Manual (C753) published by CIRIA in 2015, defines a phytoremediation as: The breakdown of pollutants in soil, water or air through the use of plants.
Pipework, also known as piping, is a system of pipes that is used to convey fluids. Careful design must ensure the integrity of pipework, with adherence to various considerations and principles.
Approved document B of the building regulations suggest that pipes: '...includes pipe fittings and accessories. The definition of pipe excludes a flue pipe and a pipe used for ventilating purposes, other than a ventilating pipe for an above-ground drainage
system.' -
National standards such as ASME B31 Code for Pressure Piping or BS 1560 Circular Flanges for Pipes, Valves and Fittings are used as requirements for the manufacture of pipes and piping components.
Many different components comprise pipework, including pipes, supports, gaskets, flanges, bolts, valves, strainers, flexible and expansion joints. These are used to sense and control the pressure, flow rate and temperature of the conveyed fluid and the system is usually documented in piping and instrumentation diagrams (P&IDs).
The term 'plumbing' refers to any system that allows the movement of fluids, typically involving pipes, valves, plumbing fixtures, tanks and other apparatus. Modern plumbing may also involve the movement of gases such as fuel gas.
The etymology of the term plumbing comes from plumbum, the Latin word for lead. This is because the first effective pipes used for the movement of water were lead pipes used by the Romans. After the Second World War, increased awareness of lead poisoning resulted in copper piping taking precedence over lead.
Although ancient Greek, Persian and Indian cities had used primitive forms of plumbing, the Romans were the first to pioneer expansive systems of plumbing, such as aqueducts, the removal of wastewater, and other sanitary features.
Today, plumbing systems might be used for:
Heating and cooling. - Waste removal.
Waste removal. - Potable cold and hot water supply.
Potable cold and hot water supply. - Water recovery and treatment systems.
Water recovery and treatment systems. - Rainwater, surface and subsurface water drainage.
Rainwater, surface and subsurface water drainage. - Fuel gas piping.
Fuel gas piping. - A plumber is a person that fits and repairs plumbing and associated fixtures. Plumbers may also take on roles involving design, management, consultancy, teaching, and so on.
A plumber is a person that fits and repairs plumbing and associated fixtures. Plumbers may also take on roles involving design, management, consultancy, teaching, and so on.
Biodiversity in new housing developments: creating wildlife-friendly communities, published by the NHBC Foundation in April 2021 suggests that residential planting: Refers to formal landscape around house and street frontage, local centres, meeting places and play areas. Mixed palettes of native and non-native plants are usually used.
The SuDS Manual (C753) published by CIRIA in 2015, defines a rhyne as: A drainage ditch or canal used to turn areas of wetland at around sea level into useful pasture.
See full history - Sanitary pipework
Sanitary pipework - Bathroom 2016 Sept 1.JPG
Bathroom 2016 Sept 1.JPG -
Sanitary pipework is above-ground pipework that is used to carry water from toilets, sinks, basins, baths, showers, bidets, dishwashers, washing machines, and so on, out of a building to the sewage system. The equivalent underground pipework is referred to as foul drainage and sewers.
According to the Building Regulations Approved Document G, every modern home must have a WC fitted that is connected direct to the drainage system, with a basin fitted next to the WC with a supply of hot and cold water. In addition, every home must have a fixed bath or shower with a hot and cold water supply, and all appliance connections that are connected to the drainage system must have a trap to prevent odours and dangerous gases building up inside.
Sanitary pipework system should be designed according to the Building Regulations Approved Document G and H, and should conform with BS EN 12056:2:2000, 'Gravity drainage systems inside buildings. Sanitary pipework, layout and calculation'.
Traditionally, sanitary pipework was manufactured using metals such as cast iron, copper or lead; however, modern designs predominantly use plastics such as uPVC, high-density polyethylene (HDPE), polypropylene and so on. They are generally connected by some form of welding (such as solvent welding) or using push-fit fittings.
The pipes are designed to different diameters depending on the appliance which they are connected. For example, a WC typically uses a 110 mm diameter pipe; baths, showers, sinks, washing machines use 40 mm diameter pipes; a bidet uses a 32 mm diameter pipe, and so on. The pipes are laid out to a slope or fall which allows wastewater to drain away without leaving debris behind and avoiding blockages.
Sanitary pipework is typically connected to a soil vent pipe (SVP) which is a vertical pipe often attached to the exterior of a building that connects the drainage system to a point just above the level of the roof gutter allowing odours to be released. Venting the stack prevents water seals in traps from being broken by pressure build ups in the system.
Technical paper 35: Moisture measurement in the historic environment, published by Historic Environment Scotland in 2021, defines saturation as: The state attained by a material when the addition of further water does not result in any further absorption.
Groynes in coastal engineering (CIRIA C793), published by CIRIA in 2020, defines sea defences as: Measures referenced under the Water Resources Act (1991) aimed at protecting lowlying coast and coastal hinterland against flooding caused by the combined effect of storm surge and extreme astronomical tides.
Sealing is the process of prevent fluids and other substances from passing through material surfaces, joints, or openings. It can also prevent the passage of air, sound, dust, insects, and so on, as well firestopping.
NB Guidance on the code of practice for property flood resilience, published by CIRIA in 2021, defines sealing as: a dry proofing technique where the floodwater does not reach the interior of the building as the external walls, floors and openings are sealed and used to hold back the floodwater.
Groynes in coastal engineering (CIRIA C793), published by CIRIA in 2020, defines a seawall as a: Structure built along the shore to prevent erosion and damage by wave action.
Septic tanks are generally installed at properties that are not connected to the public sewer network. They are typically fabricated from concrete, fiberglass or plastic and installed below ground where they collect and then to naturally treat sewage (a mixture of waste water and excrement) so that it can be drained safely to the surrounding environment.
They generally consist of two chambers. Sewage enters the first chamber via a drain. The solids within the sewage slowly settle to the bottom, and grease and oil remains at the top. These layers are slowly broken down by bacteria. This leaves a layer of clarified water in the middle that is then drained to a second chamber and then out to sub-soils in a septic drain field (also referred to as seepage field or leach field) which disperses the discharge to ensure it does not cause pollution. Drain fields should remain free from trees or hard landscaping and should not be used by traffic.
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published by BSRIA in partnership with the Closed Systems Control Association (CSCA) in March 2021, defines a sequestrant or sequestering agent as: A substance that removes a metal ion from a solution by forming a complex ion that does not have the chemical reactions of the ion that is removed. A sequestrant may be a chelating or complexing agent.
Sewers are expensive to construct and if not built correctly remedial works can be disruptive, time consuming, costly and, in some circumstances, have adverse effects on a companys reputation. In many instances, a lot of mistakes can be avoided by considering the specification and requirements before and during construction. This is an on-site guide for contractors and operatives constructing sewers, with advice notes provided to avoid some of the common on site errors.
Sewers for Adoption (7th ed.) contains guidance for the design and construction of sewers that will be adopted by Sewerage Undertakers in England and Wales in accordance with Section 104 of the Water Industry Act 1991.
Sewerage (the sewer system), is the underground networks of pipes that carries sewage (waste water and excrement), waste water and surface water run-off, from buildings to treatment facilities or disposal points.
A sewer is; 'A pipe or channel taking domestic foul and/or surface water from buildings and associated paths and hardstandings from two or more curtilages and having proper outfall' Ref The SuDS Manual (C753), published by CIRIA in 2015.
Types of sewer include: -
Sanitary sewer: Used solely for carrying sewage.
Surface water sewer: Used to drain groundwater and excess water from impervious surfaces.
Combined sewer: Used to carry both sewage and surface water. This type of sewer can lead to water pollution problems when overflow conditions are experienced.
Effluent sewer (sometimes referred to as Septic Tank Effluent Drainage (STED) or Solids-Free Sewers (SFS)) : These collect remaining sewage from septic tanks and carry it to a treatment plant.
The term sludge (or slurry) refers to a range of semi-solid/semi-liquid substances or deposits. In the United States, sewage sludge is sometimes referred to as septage (when associated with sludge from septic tanks).
n the construction industry, sludge is often produced during the excavation process as a type of mud with a high water content.
Sludge can also be generated by activities such as industrial wastewater treatment using biological or chemical processes. Industrial sludge can sometimes be produced in solid form, such as sewage sludge from wastewater treatment or faecal sludge from pit latrines and septic tanks.
A smart pump is a pump that functions in a specific way under certain conditions. When connected through a network (as other devices operate by way of the Internet of Things) smart pumps communicate with each other and with those who operate them.
Smart pumps can be used to prevent flooding. These devices are designed to respond to rising water conditions. When the water reaches a predetermined level, it completes a circuit. This causes the smart pump to operate. When the water level drops, the circuit is broken and the pump stops.
In domestic applications, a smart sump pumping system is one that uses WiFi technology to send alert messages when flood conditions are possible. They can also relay messages about the condition of the pump if it malfunctions.
According to BRE Digest 365 Soakaway design: Soakaways are used to store the immediate surface water run-off from hard surfaced areas, such as roofs or car parks, and allow for efficient infiltration into the adjacent soil. They discharge their stored water sufficiently quickly to provide the necessary capacity to receive run-off from a subsequent storm.
Traditionally they have been used as a way of disposing of surface water in areas that are remote from public sewers or watercourses, instead allowing rainwater to infiltrate directly into the ground. However, recently they have also been used in fully-sewered areas to limit the impact of new building works and to avoid the cost of upgrading sewers.
They can be square, circular, or trench excavations and can be filled with rubble, or lined with brickwork, plastic cells, perforated pre-cast concrete ring units or similar structures. They can also be deep bored.
NB The SuDS Manual (C753) published by CIRIA in 2015, defines a soakaway as: A subsurface structure into which surface water is conveyed, designed to promote infiltration.
A soil vent pipe (SVP), also known as a soil stack pipe, drain-waste-vent or ventilated discharge pipe, is typically a vertical pipe that removes sewage and greywater from a building. It is often attached to the exterior of a building (although it may be fitted internally) and connects the subterranean drainage system to a point just above the level of the roof gutter.
Soil vent pipes allow the removal of waste from toilets, showers, baths and sinks, while also allowing odours to be released above the building, via a stack vent, at a level that will not cause a nuisance. The pipes vents also allow air into the internal drainage system so as to facilitate the process of aerobic sewage digestion, preventing a siphoning affect from occurring, and allowing free flow by gravity.
SVPs must maintain sufficient downward slope along their length to keep liquids and entrained solids flowing freely towards the drain. If a downward slope is not possible, a collection pit with a sewage ejector pump can be installed.
Traditionally, soil vent pipes were made from cast iron; however, today they are most commonly made from uPVC.
Approved document H: Drainage and waste disposal requires that the foot of a discharge stack should have as large a radius as possible, and not less than 200 mm at the centre line. Offsets should be avoided in the wet section of the stack. Ventilating pipes should finish at least 900 mm above any opening within 3 m and should be finished with a wire cage or other perforated cover.
Biodiversity in new housing developments: creating wildlife-friendly communities, published by the NHBC Foundation in April 2021 defines source control as a: SuDS feature that manages run-off close to where it lands on hard surfaces. These include green roofs, rain gardens and filter strips that replace the need for gully drains and pots.
Stink pipes (or stench pipes) are Victorian era stack vents placed above drain waste vents (or DWVs). Their purpose is to provide ventilation for pipe networks that handle sewage and greywater.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines submergence ratio as: The ratio between downstream water depth above weir crest level and the upstream water depth above weir crest level
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines superelevation as an: Increase in water level due to a bend in a channel or culvert.
BG 29/2021 Pre-Commission Cleaning of Pipework Systems, Amended 6th edition, written by Chris Parsloe and Martin Ronceray, published by BSRIA in partnership with the Closed Systems Control Association (CSCA) in March 2021, defines a surfactant, or surface-active agent as: A soluble compound that reduces the surface tension of liquids, or reduces interfacial tension between two liquids or a liquid and a solid. Commonly used during the de-greasing stage of the clean. Also used to increase the effectiveness of inhibitor formulations (by improving contact) and may themselves be inhibitors.
Swales are natural or man-made linear depressions (or ditches), usually grass covered, with shallow-sloping sides. They are becoming more common as components in the drainage strategies of residential, commercial and municipal schemes.
Approved Document H - Drainage and Waste Disposal, describes swales as:
grass-lined channels which transport rainwater from a site as well as controlling flow and quality of surface runoff. Some of the flow infiltrates into the ground. There may be an overflow at the end into another form of infiltration device or a watercourse. They are particularly suitable for treatment of runoff from small residential developments, parking areas and roads.
Their function is to: -
Slow the movement of water through the landscape after heavy rainfall;
Reduce peak flows; - Form a temporary reservoir;
Form a temporary reservoir; - Direct water to a storage or discharge system and
Direct water to a storage or discharge system and
Facilitate the absorption of water into the ground.
Swales are frequently located alongside road verges, near the source of water run-off and can form a network linking storage ponds and wetlands. They can offer an efficient way of capturing rainwater and may form part of a sustainable urban drainage system (SuDS).
They can be both sustainable and economic because they are relatively easy to construct and can obviate the need for costly kerbs, gullies and gratings, as well as requiring little maintenance, other than mowing during the growing season. A grass length of around 150mm is considered optimal. Furthermore, swales can form good habitats for toads, newts and other amphibians which might have lower survival rates in conventional manufactured gullies.
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines washland as: Lowland near to a river or other channel used for the temporary storage of floodwater. Often developed for use of the erection of bunds and control structures.
Building evacuation is the process of making sure everyone inside a building gets out safely and in a timely and controlled manner in the event of an emergency, such as fire. Buildings commonly use equipment such as fire alarms, exit signage, emergency lighting and emergency escape routes to facilitate evacuations.
A simultaneous evacuation is where building occupants react to the alarm and follow the designated means of escape to the place of safety away from the building. This may not be suitable or practicable for larger or more complex buildings due to the risks of congestion at escape routes. These buildings may be designed so that evacuation is initially limited to those nearest the hazard, before being extended if necessary to others. This type of phased evacuation strategy requires different alarm signals a warning and an evacuation signal.
Cohousing is a method of living that has become established in several countries around the world. Created and run by residents, cohousing developments are communities where people not only know their neighbours but actively manage their neighbourhood alongside them.
Small enough that everyone can be familiar with each other, but large enough not to force them to be, cohousing communities are built around a shared desire for a sense of belonging, neighbourliness and mutual support that many people feel is missing from modern life and contemporary housing developments.
In cohousing communities, just as in conventional neighbourhoods, residents own or rent their own private homes. But everyone also benefits from extra shared facilities and spaces that allow members to do things together. Shared outdoor spaces provide opportunities to grow food, play and be close to nature, and a shared Common House provides additional indoor space for residents to meet, eat and socialise together. Car parking tends to be kept to a minimum and located at the periphery, allowing the central spaces close to homes to be used for other things.
Crown build projects are new-build construction projects or refurbishment projects that are funded directly by the government through the government's capital expenditure budget. The completed development remains in public ownership.
Mobilisation refers to the activities that should be carried out after the client has committed funds for construction, but before work commences on site. It is a preparatory stage during which the majority of activities are managed by the integrated supply team.
Depending on how experienced the client is, they may appoint external consultants such as independent client advisers or a project manager to assist them. This means that some of the tasks attributed to the client below might actually be carried out by independent client advisers, a project manager or a contract administrator (employer's agent on design and build projects) and vice versa.
Business justification takes place once a business need has been identified which might result in a building project. It involves assessing whether there is justification for the project, preparing a preliminary business case and creating an organisational structure for the project.
The Government Construction Strategy proposes that publicly-funded projects adopt either a design and build, private finance initiative (PFI) or prime contract procurement route. These routes involve contracting an integrated supply team (including designers, contractors and suppliers) to design, construct and sometimes finance, operate and maintain the development. Traditional procurement routes that separate design and construction should not be used unless it can be demonstrated that they offer better value.
Depending on how experienced the client is, they may appoint external consultants such as independent client advisers or a project manager to assist them. This means that some of the tasks attributed to the client below might actually be carried out by independent client advisers or a project manager and vice versa.
Publicly-funded projects are expected to commission independent peer reviews called 'gateway reviews' at key points during their development. This project plan follows the OGC (Office of Government Commerce) Gateway Review procedure. The OGC has now been absorbed into the Efficiency and Reform Group and its guidance archived, however, the OGC Gateway Review procedure is still cited by the Government Construction Strategy and remains the only complete reviewing system.
The feasibility studies stage considers the options for satisfying the client's needs, enabling them to prepare a business case for the preferred option and deciding whether to proceed with the project. It is possible to make an outline planning application during this stage if the risk to the project of not receiving planning permission is very high, or if delays in receiving planning permission would be problematic.
Depending on how experienced the client is, they may appoint external consultants such as independent client advisers or a project manager to assist them. This means that some of the tasks attributed to the client below might actually be carried out by independent client advisers or a project manager and vice versa.
Tendering is the process of selecting and appointing an integrated supply team for the main contract.
The Government Construction Strategy proposes that publicly-funded projects adopt either a design and build, private finance initiative (PFI) or prime contract procurement route. These routes involve contracting an integrated supply team to design, construct and sometimes finance, operate and maintain the development. Traditional procurement routes that separate design and construction should not be used unless it can be demonstrated they offer better value.
Depending on how experienced the client is, they may appoint external consultants such as independent client advisers or a project manager to assist them.
In physics or geometry, a cable or a chain hanging freely and acting under its own weight, supported only at its end points (not in a vertical line) and with no other load, takes the form of a catenary. This is different to the loaded cables supporting a suspension bridge, which take the form of a parabola.
The National Planning Policy Framework (NPPF) defines previously developed land (PDL, or brownfield land) as:
'Land which is or was occupied by a permanent structure, including the curtilage of the developed land (although it should not be assumed that the whole of the curtilage should be developed) and any associated fixed surface infrastructure.
'This excludes: land that is or has been occupied by agricultural or forestry buildings; land that has been developed for minerals extraction or waste disposal by landfill purposes where provision for restoration has been made through development control procedures; land in built-up areas such as private residential gardens, parks, recreation grounds and allotments; and land that was previously-developed but where the remains of the permanent structure or fixed surface structure have blended into the landscape in the process of time.'
Building pathology is a holistic approach to studying and understanding buildings, and in particular, building defects and associated remedial action.
In a medical context, pathology is the study of diseases in order to determine their causes and prescribe treatment. Similarly, building pathology involves the methodical study of buildings, their components, and environment, to address failures.
Building defects are aspects of the building that were not completed in accordance with the contract or that have failed. Defects can be 'patent' or 'latent'. Patent defects are those which can be discovered by reasonable inspection. Latent defects are those which cannot be discovered by reasonable inspection, for example problems with foundations which may not be apparent.
Defects may occur because of wide a range of issues, such as:
Design deficiencies. - Material deficiencies.
Material deficiencies. - Specification problems.
Specification problems. - Workmanship deficiencies.
Workmanship deficiencies. - Deterioration.
Deterioration. - Maintenance and repair deficiencies.
Maintenance and repair deficiencies. - Improper use.
Improper use. - Environmental and other external factors.
Environmental and other external factors. - Defects may be:
Defects may be: -
Fundamental. For example, requiring demolition, making the building unsafe or being in breach of a permission.
Functional. Affecting the clients beneficial occupancy of the building.
Cosmetic. Not affecting the clients beneficial occupancy of the building.
Building surveys are a means of providing a detailed evaluation of a property's condition and involve an extensive inspection. Whilst not being the only type of survey available to property owners, a building survey is the most common, particularly for domestic clients.
The surveys are generally undertaken to help property owners understand the condition of a property, recording risks and potential expenditure that may be required, enabling them develop the appropriate remedial or maintenance plans. They may also be prepared for individual homeowners, home buyers, or for investors in property portfolios to help inform future investments.
While some aspects may differ, building surveys are also known as condition surveys. Other types of survey might include:
Valuation. - Structural survey.
Structural survey. - Habitat survey.
Habitat survey. - Thermographic survey.
Thermographic survey. - Ecological survey.
Ecological survey. - Tree hazard survey.
Tree hazard survey. - Soil survey.
Soil survey. - Site survey.
Site survey. - 3D laser survey.
3D laser survey. -
Building wraps are large-scale printed sheet materials that can be fixed to scaffolding structures and used to conceal building work. They are commonly digitally printed with a CGI rendering or photographic image of the building faade, attempting in some way to blend in better with its context than traditional debris netting would.
It is a technique that is sometimes used on important buildings, or in sensitive locations, to hide unsightly scaffolding while providing a tantalising representation of what the building looks, or will look, like.
The benefits of building wraps are that they can help to reduce the spread of dust and other debris, conceal construction work from the public, and mean that views of the under-construction building is minimised.
Bungalow is an Anglo-derived term used to describe a style of house that originated in India and Bengal. Bungalows are characterised by their single-storey height, and were first identified by British sailors of the East India Company in the late-17th century.
However, the term refers to different specific types of building depending on the country. Ironically, in India, a bungalow is a general term that refers to any single-family building, regardless of the number of storeys. In Canada and the UK, a bungalow is typically a one-storey building. In Australia and the United States, bungalows are usually built with a half-second storey and a sloping roof.
In the construction industry, decoration refers to the dressing of a room or interior space. It can be referred to as interior decoration or 'decor' and relates to the aesthetics of a space and its furniture, furnishings, surface finishes, lighting, and so on. It generally does not include the shape of the space, position of walls, and so on.
The purpose of decoration is to make the space more aesthetically pleasing and functionally useful for the occupants, but this may include consideration of wider contextual issues such as fashion, culture, and so on.
A disbursement is a type of payment which is made from a bank account or other funds, or a payment that a third party such as a solicitor makes on behalf of their client for which they are entitled to reimbursement.
Common examples of disbursements include money paid out for the running of a business, cash expenditures, dividend payments, and payments made by an organisations solicitor to third parties for certain fees (e.g. court, medical, courier fees, expert reports, etc.).
During the conveyancing process, a disbursement is a type of payment made when property ownership is transferred from one party to another. Disbursements are not part of a solicitors basic fee, nor are they additional charges for which the solicitor receives a commission; instead they relate to various fees and taxes that must be paid.
The term exurb, exurbia or exurbian is a US reference to the residential areas well beyond the suburbs. This term is comparable to the UK term, stockbroker belt.
Garden suburbs were introduced in the late 19th century. The concept can be considered the predecessor to the exurb, which emerged in the US in the 1950s. Both were dependent on the development of improved methods of transportation.
Garden suburbs are residential areas well beyond the suburbs. They are the opposite of garden cities, which were introduced in Ebenezer Howards 1898 publication To-morrow: A Peaceful Path to Real Reform. While garden cities offered strong local job opportunities within easy commuting distance of homes, many garden suburb communities did not include commercial and industrial components.
Bournville is a noteworthy exception. Referred to as the factory in a garden", Bournville is a model village on the south side of Birmingham. It is best known for its connections with the Cadbury family and chocolate. The Cadburys named the area "Bournville" after the Bourn Brook (now known as The Bourn); with "ville" being French for "town".
Cadbury moved the factory to Bournville in 1879 and built a community for its workforce. The village is made up of hundreds of small cottages and houses with large gardens. Small developments were added over several decades. Bournville has become a model for other communities (sometimes referred to as villages or village estates) throughout the UK.
The Town and Country Planning Association (TCPA) suggests that a garden city is a ...holistically planned new settlement which enhances the natural environment, tackles climate change and provides high quality housing and locally accessible jobs in beautiful, healthy and sociable communities.
They were described in Ebenezer Howards 1898 publication To-morrow: A Peaceful Path to Real Reform as having, ...the advantages of the most energetic and active town life, with all the beauty and delight of the country...'
Howard went on to become founder of the Garden City Association (now the Town and Country Planning Association) and by 1903, land had been purchased for the first Garden City at Letchworth. This was followed in 1919 by land acquisition for the creation of Welwyn Garden City. These projects were followed by the New Towns programme in the aftermath of the Second World War, which promoted the development of larger, 'new towns' such as Milton Keynes.
The Garden City idea has remained popular, and the TCPA suggests that 21st century Garden City principles include:
Land value capture for the benefit of the community.
Strong vision, leadership and community engagement. - Community ownership of land and long-term stewardship of assets.
Community ownership of land and long-term stewardship of assets.
Mixed-tenure homes and housing types that are affordable for ordinary people.
A strong local jobs offering within the garden city, with a variety of employment opportunities within easy commuting distance of homes.
Beautifully and imaginatively designed homes with gardens, combining the very best of town and country living to create healthy homes in vibrant communities.
Generous green space linked to the wider natural environment, including a surrounding belt of countryside to prevent sprawl, well connected and biodiversity-rich public parks, and a mix of public and private networks of well-managed, high-quality gardens, tree-lined streets and open spaces.
Opportunities for residents to grow their own food, including generous allotments.
Strong local cultural, recreational and shopping facilities in walkable neighbourhoods.
Integrated and accessible transport systems with a series of settlements linked by rapid transport providing a full range of employment opportunities (as set out in Howards vision of the Social City).
Healthy Streets and its 10 Indicators are concepts that first appeared in Transport for London policy in 2014. The programme was developed by Lucy Saunders, a specialist in public health and transport, and the term was officially introduced by London Mayor Sadiq Khan in October 2016. This approach to urban development puts the emphasis on streets that promote active pedestrian and public transport travel, have clean air and are safe.
The goal of Healthy Streets is to design a long-term plan that encourages people to walk and cycle throughout London. While this concept will be applied differently based on location, examples such as the pedestrianisation of Oxford Street and the Rotherhithe to Canary Wharf cycle bridge are part of the plan.
The term housing tenure refers to the legal status under which people have the right to occupyaccommodation.
The term 'leaseback' (also known as sale-and-leaseback) refers to a financial arrangement in which the party selling an asset (usually property) leases it back from the purchaser. This is generally a long-term arrangement, allowing them to use the asset but no longer owning it. The seller of the asset becomes the lessee, and the purchaser becomes the lessor.
Companies often raise capital by taking up debt and giving up equity, in order to grow the business. Leaseback is neither debt nor equity; the company doesnt increase its debt load but gains access to capital through the sale of assets, while not having capital tied up in the asset. Tax benefits can sometimes be gained through the use of leasebacks.
The arrangement is rather like that of a pawnshop in that a company exchanges a valuable asset for a certain amount of money. The difference is that there is no expectation that the asset will be bought back by the company.
Land value is the amount of money that a piece of land, along with the property contained on it, is priced at. This includes any improvements that have been made to the land. Land values increase when demand exceeds the supply, or if the land has intrinsic value greater than neighbouring areas, for example, if it has an oil supply or fresh water.
Maintenance is the process of ensuring that buildings and other assets retain a good appearance and operate at optimum efficiency. Inadequate maintenance can result in decay, degradation and reduced performance and can affect heath and threaten the safety of users, occupants and others in the vicinity.
Depending on its design, quality of materials and workmanship, function and location, buildings deteriorate at different rates and require different levels of attention. No building will ever be maintenance-free, but the quality of the design and workmanship can minimise the level required.
Maintenance can help: -
Prevent the process of decay and degradation. - Maintain structural stability and safety.
Maintain structural stability and safety. - Prevent unnecessary damage from the weather or from general usage.
Prevent unnecessary damage from the weather or from general usage.
Optimise performance. - Help inform plans for renovation, refurbishment, retrofitting or new buildings.
Help inform plans for renovation, refurbishment, retrofitting or new buildings.
Determine the causes of defects and so help prevent re-occurrence or repetition.
Ensure continued compliance with statutory requirements. - For maintenance to be most effective, it should be organised through a programme of cyclical maintenance. At the most basic level this includes daily routines, and works upwards to periodic programmes of weekly, monthly, semi-annual, annual, quinquennial and so on routines.
For maintenance to be most effective, it should be organised through a programme of cyclical maintenance. At the most basic level this includes daily routines, and works upwards to periodic programmes of weekly, monthly, semi-annual, annual, quinquennial and so on routines.
At the quinquennial point and beyond, architects, engineers and surveyors may become involved to inspect for structural and other serious defects (in particular for historic buildings), and the long-term maintenance plan may be revised and updated.
A masterplan is a framework within which a location is encouraged to develop or change.
Great provinces and historic cities are often held up as prime examples of masterplanning, however current masterplanning practice is a relatively recent development.
Great provinces and historic cities are often held up as prime examples of masterplanning, however current masterplanning practice is a relatively recent development.
Micro dwellings are single residential units that tend to range from 14 to 46 square metres. They can be built a foundations or other platforms or sometimes on wheels and typically have living quarters (kitchen, bathroom, sleeping accommodations), utilities (water, electricity, sewer connections) and are suitable for full time occupancy.
A multi-storey car park (MSCP) is a stacked car park that has multiple storeys, may be enclosed and can be an independent building.
Vehicles flow between floors by means of interior or exterior ramps, vehicle lifts or automated robot systems.
MSCPs must be designed with regard to the heavy and varying loads and other physical stresses that are imposed by moving vehicles. The most common structural system for MSCPs is a precast concrete frame or post-tensioned cast-in-place concrete frame. This involves structural wall panels, floors, beams, slabs, stairs, and columns. The design aim is to achieve as large a floor span as possible without requiring supporting columns as these restrict the available area for parking. The frame may be kept open to the elements or a faade can be installed to enclose or partially enclose the interior.
For facilities managers, move management relates to the process of moving staff members from one location to another.
Small moves are usually associated with the term 'move, add, change' (also referred to as MAC). MACs take place, for example, when an existing employee changes jobs and needs a new workspace that reflects their new position, or when a new staff member joins a team and requires a workspace that is in close proximity to other members of the same department.
Larger moves (sometimes referred to as project moves) may occur, for example, when an entire department moves to a new location. The location can be on the same site or it can be in a different location entirely. Due to their scope, project moves can be much more complicated to coordinate.
Whether large or small, staff moves typically involve working to standards that can be logged and tracked, set out in procedures that have been agreed by the decision makers in charge of the move.
Overbuild is a relatively recent term that has come to mean achieving better land use by building over existing public assets to create new residential accommodation without the need to find greenfield sites. Thus, new apartments could be created above a library, university building or other building type.
More recently, an off-shoot of general overbuild is rail overbuild decking over railway lines and/or railway land to create new residential accommodation. Given the shortfall in UK housing, especially in London, the technique received significant national and international attention during 2018, primarily due to a study entitled Out of Thin Air by global engineering consultancy WSP.
The term 'penthouse' is used to describe an apartment on the top floor of a high-rise building. According to the New York City building code, a penthouse is ...an enclosed structure on or above the roof of any part of a building, which is designed or used for human occupancy. Penthouses are frequently the largest, most luxurious, and therefore the most expensive, apartments in a building.
In architectural terms, a penthouse is a single-occupancy living space built onto the rooftop as an additional floor, set back from the outer walls. These setbacks act as terraces and allow for significantly larger open spaces than cantilevered balconies. Some penthouses may have two or more levels. These might be referred to as a 'duplex', 'triplex' and so on.
Penthouse apartments became popular in New York during the Roaring Twenties', as economic growth created many of the first skyscraper developments. Wealthy Americans equated luxury and prestige with having the best view from a building, and so favoured the top floor apartments.
The term pepper-potting is a form mixed tenure development. It describes an urban planning strategy in which poorer and more affluent residents live in a mixed community through the sprinkling of social housing amongst privately-owned housing. Other forms of mixed-tenure development may provide a more structured, less random mix, perhaps clustering different types of resident in different streets, or parts of a development.
It is thought by some that this mixing of people from different socio-economic backgrounds creates more diverse, socially cohesive and interesting communities and helps to improve social mobility. The alternative system of uniform estates or mono-tenure' developments can lead to segregation of different socio-economic groups and to the creation of deprived ghettos.
Pepper-potting can also be used as a policy to compel developers of private housing to make some provision of social housing.
The term leasehold in property law describes a lease from the freeholder of a property that enables the leaseholder to use the property for a specified period subject to conditions set out in the lease in return for the payment of rent. At the end of the lease, the premises revert to the freeholder. Leaseholders are sometimes referred to as tenants.
A leaseholder may be able to purchase the freehold (this process is known as leasehold enfranchisement). This can be either by agreement with the freeholder, or for houses or flats, can be by right. A leaseholder may be able to purchase a freehold by right if they have owned the lease to a house for at least two years, or if they own a flat, they may be able to buy it collectively with other leaseholders (see Shelter, Buying the freehold of a house for more information). Leaseholders of flats and houses may also have the right to extend their lease, but this can be expensive.
Public Private Partnerships (PPPs) are a very broad range of partnership where the public and private sectors collaborate for some mutual benefit.
PPPs were first developed in the UK in the 1990s in the belief that private sector companies might be more efficient at providing certain services than public authorities and so could deliver better value for money for taxpayers.
PPPs can cover a range of partnerships to deliver policies, services, buildings or infrastructure, from hospital catering to maintenance and renewal of London Underground. Partnerships can be with either central or local government.
The three main categories of PPP are: -
Concession contracts, where a private sector company provides a concession on behalf of a public authority, for which the public pays them (such as a toll road).
Private Finance Initiatives (PFI), where a private sector company finances and provides a public service that might include construction, maintenance and operation, for which they are paid by a public authority.
Institutional PPP where a joint venture company is established jointly by a public authority and a private company to provide a public service.
In 1992 Chancellor of the Exchequer Norman Lamont made an announcement relating to "ways to increase the scope for private financing of capital projects", this became the Private Finance Initiative (PFI).
Private Finance Initiatives are a form of Public Private Partnerships (PPP), one of the procurement routes preferred by the Government Construction Strategy for central civil government projects. Traditional procurement routes that separate design from construction are not preferred unless it can be demonstrated they offer better value for money.
On PFI projects, a single integrated supply team is appointed with design, construction and facilities management expertise to design and build a development and then to operate it for a period of time. A special purpose vehicle (SPV), of which the integrated supply team is a part, finances the project and leases it to the government for an agreed period (perhaps 30 years) after which the development reverts to government ownership.
As this is a very long-term relationship, entered into before any design work has been undertaken, it is extremely important that the client defines their requirements properly, in particular the quality that is required and how it will be judged.
A porch is a covered, single-storey structure that can be enclosed, and projects out from a house or other building. It is a particularly popular option for extending a domestic building, typically at the front entrance, where it can provide additional space, allow the creation of a draft lobby and create an architectural focus. It can also be relatively inexpensive to construct.
A porch can help reduce heat loss from the building, improve energy efficiency and create useful storage space for coats and shoes.
Generally, a porch consists simply of low-level brick dwarf walls, columns, windows and a door. It will require foundations, and the junctions between the walls of the porch and those of the existing building will need to be properly sealed.
Internally, they can be left as open brick or plastered and painted. They will often have a light fitting and an electric socket and a door bell, intruder alarm or other entry system.
Pocket homes are a type of flat developed by Pocket Living. They were created by chief executive Marc Vlessing as a solution to the problems faced by London's Generation Rent. His answer was to make them smaller.
Pocket homes are 38 sq. m but are designed with the psychology of space in mind, appearing to be larger than they are. They incorporate underfloor heating rather than radiators, showers rather than baths, and high ceilings to maximise natural light. Each flat has a hallway with utility cupboard and storage space, open plan kitchen and dining area, living space, and a separate bedroom. To maximise land use, the flats do not come with car parking.
The average Pocket home is 20% cheaper than a conventional flat.
Potential purchasers must be first-time buyers earning less than the Mayor of Londons affordable housing limit (up to 90,000 per household as of 2018), and must be living or working in the relevant borough. When the buyer comes to sell the Pocket home, they must also sell to someone earning below the limit, which effectively caps the property value by aligning it to wage increases rather than property prices.
The term premises refers to a building together with the land on which it is situated and any outbuildings. It comprises property which may be occupied by a business or person(s). Property can be defined as something that a person or business has legal title over. Having legal title over property provides the owner with certain enforceable rights.
Use of the term premises originated from a Latin phrase included in the title deeds of property owners, which translated as the aforementioned; what this document is about.
See full history - Property chain
Property chain - The term property chain, sometimes referred to as a housing or real estate chain, describes a sequence of homebuyers and sellers whose transactions are dependent on one another.
The term property chain, sometimes referred to as a housing or real estate chain, describes a sequence of homebuyers and sellers whose transactions are dependent on one another.
Each member of the chain is both selling and buying a property, other than those at the beginning, who are only buying, and those at the end, who are only selling. There can many people involved in a property chain, each with an estate agent, solicitor, surveyor, mortgage lender, and so on.
Property chains develop because a homebuyer will generally need to sell their current home in order to finance the purchase of a new home. The seller of the home they are buying will generally require the sale to finance their own new house purchase, and so on.
A property chain can be a slow and complicated process and can frequently collapse. If one particular party is delaying the process, it will impact upon the entire chain, therefore, the chain will only progress at the pace of the slowest link. It is the responsibility of the respective solicitors to ensure that the chain progresses towards its conclusion.
Property can be defined as something that a person or business has legal title over. Having legal title over property provides the owner with certain enforceable rights.
Property may be categorised as tangible (real) or intangible. In the built environment, tangible property refers to real estate or land, whereas personal property, or chattel, is all that which is not real property.
In English common law, property includes all structures integrated with or affixed to the land, such as; buildings, dams, ponds, canals, roads, and so on. Property tends to have a monetary value attached to it and is therefore treated as an asset. However, it can also be seen as a liability, for example, if there is contamination on land or if someone is injured while on land and a court holds the property owner responsible for not preventing their injury.
Property can also be viewed as: -
A means to an end, providing space for a business to establish a working environment.
An investment. - A corporate asset that can be used as collateral to raise money.
A corporate asset that can be used as collateral to raise money.
A development opportunity in which profit can be generated by adding value.
Property ownership is one of the key tenets of the capitalist socio-economic system. Adam Smith, one of the foremost capitalist thinkers, wrote that one of the sacred laws of justice is to guard a persons property and possessions.
Start-up technology companies are seeking to challenge the construction, real estate, and property management sectors, and the proliferation of mobile technology has drastically changed consumer behaviour, creating a culture of always online users.
In conjunction with this move towards technology, the term PropTech was introduced in the 1990s during the tech bubble. It is derived from the words property and technology and is used to describe emerging start-up technology companies that are influencing and disrupting the property market.
PropTech is relatively well established in the real estate lexicon and is generally considered the umbrella concept for the terms associated with tech and other aspects of property management and construction. Initially, PropTech referred to buying, renting, selling, managing, designing and constructing residential and commercial properties. Now it is primarily associated with pre-construction activities (such as property sales and leasing issues) along with post-construction tasks (such as operations and maintenance).
PropTech is often used in conjunction with ConTech, a term that broadly describes the intersection of construction and technology. ConTech identifies advanced construction technology.
Start-up technology companies are seeking to challenge the construction, real estate, and property management sectors, and the proliferation of mobile technology has drastically changed consumer behaviour, creating a culture of always online users.
ConTech is a phrase that has been coined to identify advanced construction technology. It broadly describes the intersection of construction and technology. ConTech is often used in conjunction with the term PropTech, which is derived from the words property and technology. This refers to emerging technology companies that are influencing and disrupting the property market.
A property valuation is an inspection carried out to help determine the current market value of a property.
It is usually undertaken by an estate agent or an independent valuer, typically acting on the instructions of the vendor or a lending institution who are considering funding its purchase. Buyers may also request a property valuation if they are considering purchasing a property, in addition to structural surveys that assess its physical condition.
Before providing a mortgage or refinancing, a lending institution (such as a bank) may request a valuation to ensure the loan can be covered by the security value of the property. This is gives them with the confidence to lend the capital, knowing that if the mortgage goes unpaid, they can recover any outstanding amount by re-selling the property.
BAMB (Buildings As Material Banks) is a EU Horizon 2020 research and innovation project enabling a shift to a circular building sector. The purpose of the BAMB project is to reduce waste and the use of virgin materials in the building industry.
A number of of concepts have been developed within the project:
Buildings levels - Material(s) Bank
Material(s) Bank - Circular business models
Circular business models - Materials Passport
Materials Passport - Reuse potential
Reuse potential - Transformation capacity
Transformation capacity - Reversible Building, ~ Building Design
Reversible Building, ~ Building Design - Circular Building Assessment
Circular Building Assessment -
Defining different building levels is a way to analyse buildings by breaking them down into successively smaller or simpler units, e.g. into elements, components and materials.
However, depending on the purpose of the analysis, buildings can be broken down in various ways, e.g. by functional, physical, legal or economic characteristics. Accordingly, a common terminology could not be developed.
Material(s) banks are repositories or stockpiles of valuable materials that might be recovered. If those materials replace primary resources used during the construction, operation or refurbishment of buildings and their parts, the need for primary resource mining, for example, of rare earth elements, can be eliminated.
This idea of urban mining implies effective material reuse and thus the realisation of material loops. Nevertheless, to enable and facilitate the harvesting of materials or building parts, it is necessary to design them in a reversible way.
Materials passports are electronic and interoperable data sets that collect characteristics of materials and assemblies, enabling suppliers, designers and users to give them the highest possible value and guide all towards material loops.
The availability and relevance of this data, in particular of the use history and reuse potential of a component, facilitates reuse, recycling and biodegradation of that component. Moreover, it is crucial for choosing components that can be reused in the future. Accordingly, the development of materials passports is seen as a mechanism to encourage innovative product design and the implementation of circular business models.
The reuse potential of an assembly is a measure that expresses the likelihood that the parts of that assembly can be disassembled simply, fast and without damage, and thus reused.
Reuse potential can be calculated for a smaller assembly or for a whole building. It relies on aspects such as the compatibility and independence of its parts, and evaluates criteria such as functional and technical autonomy, assembly sequence, connection reversibility and component geometry.
A circular business model describes how companies can generate revenue or make profit, including the way it operates and finances its activities, within a circular economy.
Uncommon to the business models typical of a linear economy, circular business models describe how, for example, offering services, leasing components and taking back materials are profitable activities. Therefore, the models should identify, in the idea of a circular economy, the cost of those activities and the (market) value of the involved components and materials.
Transformation capacity is a measure that expresses the effectiveness and efficiency of altering the functional and physical characteristics of a building or its parts to meet changing needs and requirements.
At building level, transformation capacity reflects both technical and spatial aspects determining, for example, the feasibility and impact of functional building re-conversions. At assembly level, transformation capacity expresses the effectiveness and efficiency of reconfiguring to meet new performance standards.
Circular Building Assessment is an assessment approach and method that aims to provide a holistic evaluation and interpretation of multiple sustainability aspects of buildings and their parts.
Taking a life cycle approach, aspects that are included are the environmental impact, financial costs, health consequences and social value of the object under study. Developed within the BAMB-project, Circular Building Assessment fosters better informed decision-making about circular alternatives compared to linear, business as usual options.
Building design is the process of taking a client's requirements for a new building or changes to an existing building and translating them into an agreed design that a contractor is then able to construct.
The term 'base year' refers to the year that is the startingpointfor a series of years in an economic or financial index. It can be used for comparingbusinessactivities, economic growth,measuringinflationand so on across a number of years.
Block planning is an industrial planning system used for in-house production. A product type can be produced in different variations using the same resources and following the same basic process plan. Block planning supports the production planning and scheduling for this type of system. A block represents a pre-defined sequence of production orders of variable size.
Block planning enables the planning or pre-assignment of resource capacities in the production process for products with specific attributes. It enables a more rational and efficient use of those capacities. Blocks are defined with specific duration and attributes, for example, three days per block on which products are manufactured in various colours.
A construction consolidation centre (CCC) is a distribution facility that can be used in the process of managing project logistics, channelling material deliveries to a large, single construction site or a number of different sites. It facilitates the efficient flow of materials through the supply chain, reducing waste and other issues such as congestion.
Construction materials are delivered from suppliers to the CCC where they are stored until call-off from the site, at which point the CCC operator makes up and delivers a consolidated load. This is done on a just in time basis, for enhanced efficiency.
Usually, the main contractor takes the decision to use a CCC and so carries the cost. However, subcontractors, suppliers and hauliers all see the benefit and so there can be an effort to spread the costs.
While distribution centres have been commonly used in other sectors in the UK, currently there are only a few examples of CCCs. The Heathrow Consolidation Centre (HCC) was established in 2001 for the ongoing work at Heathrow airport. In 2005, the London Construction Consolidation Centre (LCCC) was set up as a pilot study. Subsequently, Wilson James took over the LCCC and relocated it to Silvertown, near City Airport. The house builder Taylor Wimpey has set up Taylor Wimpey Logistics which consolidates materials in a Newmarket facility that then provides for its sites across England and Wales.
Earned Value Management Handbook, Published by the Association for Project Management in March 2013 suggests that cost variance (CV) is: the cost comparison of what has been earned with what has been spent.
Cost variance can be calculated as: -
CV = Budgeted Cost of Work Performed (BCWP) Actual Cost of Work Performed (ACWP)
Or: -
CV% = (CV/BCWP) x 100
Construction projects are often subject to delays, irrespective of whether the contractor is or is not to blame. A delay claim for one day (or however number of days are involved) means the construction scheduled for that day was not completed, which could have severe financial implications and adversely affect the project's progress.
Delay analysis identifies why delays occur on a construction project and the impact they are expected to have on the overall programme. The outcome of the analysis may lead to legal action brought by one party to the contract.
Dilapidations are breaches of leases due to the condition of the property being leased, either during or at the end of the lease period. This may result from mistreatment of the property or poor or absent maintenance or repairs that are required by the lease. Further work may also be required at the end of a lease to reinstate alterations that have been made to the property by the tenant.
Tenants should be clear about their responsibility for dilapidations and reinstatement when signing a lease or carrying out alterations and should budget and account for any necessary works during the course of the lease. If they fail to do this they face the prospect of unexpected, or unaffordable works, or having insufficient time to carry out the works before the end of the lease.
Digital technology refers to the systems, hardware and processes that use digital data or signals to achieve a particular set of user-defined results. It pervades most walks of modern life and is the basis for telecommunications, computer systems, navigation and photography, but also manufacturing and finance, to name but a few.
In construction, digital technology has caused a cultural shift and comprises the set of tools that use and manipulate digital data to help improve, deliver and operate the built environment. These tools include:
Use of drones to facilitate site surveys - Facilitating remote meetings (eg Skype)
Facilitating remote meetings (eg Skype) - Artificial Intelligence (AI) and machine learning.
Artificial Intelligence (AI) and machine learning.
3D printing - Communications such as email.
Communications such as email. - Software such as computer aided design, computer aided manufacture and building information modelling.
Software such as computer aided design, computer aided manufacture and building information modelling.
Internet of things. - Cloud-based computing
Cloud-based computing - Virtual reality
Virtual reality - Digital technology has brought about improved collaboration within the building team, and between it and other stakeholders. It has also resulted in new materials and processes, greater innovation and buildings that would have been either very difficult or impossible to design and construct before the advent of the digital revolution. Digital technology is not only achieving better results at every level, but is also helping to make construction safer, more collaborative and more efficient.
Digital technology has brought about improved collaboration within the building team, and between it and other stakeholders. It has also resulted in new materials and processes, greater innovation and buildings that would have been either very difficult or impossible to design and construct before the advent of the digital revolution. Digital technology is not only achieving better results at every level, but is also helping to make construction safer, more collaborative and more efficient.
Durability is the resistance to degradation of products, materials, buildings and other built assets over time. This can be a difficult property to assess - whilst a tough material may be hard to the touch but it may also be non-durable if it decomposes or is eroded in a relatively short period of time.The opposite can also be true.
Many factors affect durability, whether concerning the nature of the material itself or the way it has been assembled with other materials:
Molecular structure. - Resistance to damp, moisture and water.
Resistance to damp, moisture and water. - Resistance to corrosive substances.
Resistance to corrosive substances. - Resistance to vermin and other aggressive animal life such as wood boring beetles.
Resistance to vermin and other aggressive animal life such as wood boring beetles.
Resistance to mould and rot. - Fire resistance.
Fire resistance. - Ability to accept movement.
Ability to accept movement. - Resistance to atmospheric pollution.
Resistance to atmospheric pollution. - Resistance to heat and cold.
Resistance to heat and cold. - Capacity for moisture absorption.
Capacity for moisture absorption. - Surface profiles, orientation, texture and colour.
Surface profiles, orientation, texture and colour.
As well as its constituent materials, a building as a complete entity may also be said to be durable (or non-durable). Buildings constructed for temporary purposes, such as demountable site cabins and exhibition pavilions, do not tend to stand the test of time because they are not designed to.
Viability is a measure of the likely success of a particular action or set of actions. An assessment of economic viability is an evaluation of the various economic effects that may result from the implementation of a particular project. This assessment will help decision makers decide whether a project is feasible or not.
Assessing economic viability is informed by financial analysis and the main tool which is usually used for this is cost benefit analysis (CBA). This involves expressing costs and benefits in monetary terms to allow comparisons to be made. But other non-financial benefits may also be explored. If at th
Energy cost is: The total energy cost from space heating, water heating, ventilation and lighting, less the costs saved by energy generation as derived from SAP calculations and assumptions. This is measured in /year using constant prices based on average fuel prices for 2012 (which input into the 2012 SAP calculations) and do not reflect subsequent changes in fuel prices. Energy costs for each dwelling are based on a standard occupancy and a standard heating regime.
Environmental scanning is a process in which an organisation monitors its internal and external environment as a means of formulating or altering a strategic plan. It involves the ongoing tracking of trends, occurrences, patterns and relationships within its different environments and detecting early indications of opportunities or threats to the current and future plans of the organisation.
In a construction context, an organisation may gather information about the external environment; its competitors, pricing, technology, legislation, government policy, consumer behaviour, as well as information about its internal environment; its strengths and weaknesses.
This allows the state of the organisation to be assessed, and compared to the vision for where it plans to be in five or ten years time. This can be used to develop a forward strategy, identifying changes to company policy, objectives, activities and so on that can be made.
One popular method of environmental scanning is SWOT analysis. Each letter stands for one area to review: Strengths, Weaknesses, Opportunities, and Threats. The strengths and opportunities are factors within the company, and the weaknesses and threats come from sources outside the company.
Most scans include a thorough look at competition, economics, technology, legal issues, and social/demographic factors.
The term estimate is a very broad one that refers to any activity that attempts to quantify something. In the construction industry, it is typically used in relation to the approximate costs associated with a construction project, used, for example to assess the viability or affordability of the project or aspects of it.
An estimator, also known as a cost planner or cost engineer, is responsible for calculating how much it will cost a supplier to provide a client with products or building work. The estimator typically becomes involved during the tender process when a supplier is submitting a bid to try and win a contract. They are concerned with pricing the contract competitively but need to ensure that, if they are successful, the work/products can be provided whilst still making a reasonable profit for the supplier.
Expediting is a project management activity which monitors the supply chain to ensure goods and items that have been ordered for a construction project arrive on time and meet the quality specified.
Construction projects particularly large ones can involve significant quantities of materials, labour and other services. A large contractor may have to manage thousands of employees and hundreds of tonnes of material and other products. Delays in the supply of products, materials or equipment can mean the project will not be completed to time or on budget. As well as the extra, unforeseen costs involved, such delays can destroy reputations and even result in job losses or claims.
Expediting is used to manage such risks and ensure the project is completed within the specified contract dates. It involves following-up purchases to ensure that items ordered are delivered on time and to the point required by the contractor.
Extra over (EO) is a term that is often used when taking off for a bill of quantities (BoQ). Taking off is the process of identifying elements of construction works that can be measured and priced.
When taking off for a BoQ, the term extra over can be used to refer to items that to a certain extent have already been measured, but have not been priced at the full value of all their labour and materials. A common example of this is when measuring drain pipes, for which the estimator may determine a cost based on the full length of the pipe measured along its centre-line, and then assess an extra over cost for the additional cost necessary to pay for fittings such as bends and junctions. So the cost of a section of pipe with a bend is the cost of the length of the pipe plus the extra over cost for the bend.
EO items should be listed directly beneath the main item over which they are measured, as this simplifies the the interpretation of the BoQ by suppliers. If the EO item cannot be listed immediately beneath, reference should be given in its description in the main item it relates to.
The bill of quantities (sometimes referred to as 'BoQ' or 'BQ') is a document prepared by the cost consultant (often a quantity surveyor) that provides project specific measured quantities of the items of work identified by the drawings and specifications in the tender documentation.
The quantities may be measured in number, length, area, volume, weight or time. Preparing a bill of quantities requires that the design is complete and a specification has been prepared.
The bill of quantities is issued to tenderers for them to prepare a price for carrying out the works. The bill of quantities assists tenderers in the calculation of construction costs for their tender, and, as it means all tendering contractors will be pricing the same quantities (rather than taking off quantities from the drawings and specifications themselves), it also provides a fair and accurate system for tendering.
The contractor tenders against the bill of quantities, stating their price for each item. This priced bill of quantities constitutes the tenderer's offer. As the offer is built up of prescribed items, it is possible to compare both the overall price and individual items directly with other tenderers' offers, allowing a detailed assessment of which aspects of a tender may offer good or poor value. This information can assist with tender negotiations.
A fee proposal is a proposal prepared by a consultant for a prospective client describing the services that the consultant proposes to undertake and the fee that will be charged. This may be in the form of a letter, or may be a more detailed document accompanied by a cover letter.
It is very important that the nature of an appointment is set out in detail before work commences to avoid potential confusion or misunderstanding of what is expected, how much it will cost, and what is not included, and to prevent scope creep. Institutes such as the Royal Institute of British Architects (RIBA) include a requirement for a written agreement of appointment in their code of conduct.
A fee proposal may be prepared in response to a formal request for proposals prepared by the client, which sets out the nature of the project, the clients requirements and the information that they expect the consultant to include in their proposals, (generally described as the consultants proposals), or it may be prepared following more informal communications with the client.
A financial year sometimes called the tax period, accounting period, fiscal year or budget year is the period of time, usually 12 months, that is used for accounting purposes and for the submission of taxes to the Inland Revenue.
Organisations use the financial year to report on their progress and measure whether they have met their operational goals for that year. This helps them to plan for the following year.
For some businesses, it is preferable for their financial year to run from April 1 to March 31 the following year a full 365 (or 366 days if a leap year). This aligns with the governments fiscal year. However, for personal tax purposes, the year runs from April 6 to April 5 a period which reflects the old ecclesiastical calendar.
Firms and individuals are free to choose an accounting period that is convenient to them, as long as they have informed the Inland Revenue. Operating a financial year that accords with the calendar year January 1 to Dec 31 is preferable for some. Many large organisations in the UK use the calendar year as their accounting period, whereas for universities it typically ends during the summer to align with the close of the academic year.
The term functional condition indexation (FCI) refers to:
the ratio of the functionalcost estimateof predictedlife cyclemajorrepairsor replacements (identified by aconditionandRemaining lifeassessment) to the Capitalised replacementvalueor rebuildcosts, expressed over an agreed period of analysis (e.g. abandingof years such as 1, 2 to 3, 4 to 5, 6 to 10 or 11+).
Capital Works Management Framework, Guidance Note, Glossary, Published by the Government of Ireland Department of Finance in 2009 suggests that:
Function Analysis is a way of breaking down project objectives into their component parts and determining how they contribute to the overall project objectives. A completed function analysis shows what the financial investment buys for a client. Successful function analysis drives innovative project decisions, and also forms a basis for risk management and for value management.
The rough estimate of global cost of the entire project is often based on functional unit costs multiplied by number of units according to the established norms in a sector. For example, construction costs for a school could be based on a norm of 6 m2/per pupil @ 100/m2; so, a rough estimate for a 1,000 pupil school would be 6 x 100 x 1,000.
Gross value added (GVA) is an economic metric that quantifies the value added to goods and services produced. This is representative of the contribution to the economy of producers, or the wider industry or sector.
It can be determined by the production approach, the income approach or the expenditure approach:
The production approach estimates the value of output goods or services minus the value of inputs to the production process.
The income approach determines the incomes earned by individuals and corporations producing the goods or services.
The expenditure approach determines total expenditure on goods and services produced in the domestic economy.
GVA is often used in calculating the gross domestic product (GDP, a measure of the state of the economy as a whole).
RICS Insight Paper Value of natural capital - the need for chartered surveyors published by the Royal Institution of Chartered Surveyors in 2017, describes hedonic pricing as a revealed preference method of valuation that draws on the revealed preferences of stakeholders.
In hedonic pricing: 'property transaction data are analysed to determine the influence of the factor being valued, for example proximity to open space or location in a National Park. This relies on having sufficient data to produce a robust analysis.'
A Homebuyer Report is a type of building survey.
Building surveys are a means of providing a detailed evaluation of a propertys condition. They may also be prepared for individual homeowners, home buyers, or for investors in property portfolios to help inform future investments.
HomeBuyer Reports were introduced in 2009, and follow a format specified by the Royal Institution of Chartered Surveyors (RICS). They are sometimes referred to as a Homebuyer Survey.
The term hourly rate refers to the amount of remuneration a worker/employee receives for each hour that they work. Those who are paid at an hourly rate can be described as doing time work, unlike salaried workers who are paid a fixed salary regardless of the amount of time they work. Hourly rates tend to apply to part-time and manual labour, particularly in construction where tradespeople and site labourers are often paid by the hour.
Construction sites can sometimes be fitted with a clocking-in device that monitors the precise time that operatives arrive and depart, allowing them to be paid by the minute, or it can be rounded up or down to the nearest half hour. Weekends, Bank Holidays and evening work can be paid at a higher hourly rate as an employee incentive.
Approved document F, Ventilation, defines airtightness as a general descriptive term for the resistance of the building envelope to infiltration with ventilators closed. The greater the airtightness at a given pressure difference across the envelope, the lower the infiltration.
It suggests that air permeability is the physical property used to measure the airtightness of the building fabric. It is defined as air leakage rate per hour per square metre of envelope area at a test reference pressure differential across the building envelope of 50 Pascal (50 N/m2). The design air permeability is the target value set at the design stage.
The Air Tightness Testing and Measurement Association (ATTMA) defines air leakage as the '...uncontrolled flow of air through gaps and cracks in the fabric of a building. It is sometimes known as infiltration or draughts. Air leakage is not to be confused with ventilation, which is controlled airflow in and out of a building'.
The term antiquities refers to artefacts from ancient history or antiquity, i.e. the civilisations of Ancient Greece, Rome, Egypt and other Eastern cultures.
In terms of architecture, antiquities can be said to be the styles of classical architecture that stemmed from those ancient civilisations and those dating later that were influenced by them. Although there are a wide range of classical architectural styles - and some such as the Gothic style, which are sometimes classed as classical and sometimes not they all conform to common vocabulary of decorative and constructive elements.
In classical architecture, the term arcade refers to a series of arches supported by columns or other vertical elements such as piers. This can be used to form a passageway between arches and a solid wall, or a covered walkway providing access to commercial buildings or markets. Arcades are structurally very strong, and so can carry large loads and stretch for large distances.
Arcades were first developed by the Romans, who took inspiration from ancient aqueduct designs. They used arcades to construct large wall structures; the most famous example being the Colosseum in Rome which has 80 arcaded openings on its first three storeys.
Roman arcades came to be distinguished by the use of pilasters that were attached to piers carrying an entablature. The form developed to become arches resting on the capitals of a row of columns. This style was also adopted during the Gothic period as a decorative element used to divide a churchs nave wall into three horizontal parts.
Arcades have also featured in medieval cloisters, Islamic courtyards, Renaissance commercial streets, Middle Eastern bazaars, Baroque marketplaces, and modern shopping centres.
An arch is a curved structural form that carries loads around an opening, transferring them around the profile of the arch to abutments, jambs or piers on either side.
Arches have been a prominent feature in architecture since the time of the Etruscans who are credited with its invention, although the Romans developed it further and spread its use. The techniques involved in designing and constructing arches have since developed into many other structural forms, including vaults, arcades and bridges.
Arches are compressive structures, that is, there are no tensile stresses. They are self-supporting, stabilised by the force of gravity acting on their weight to hold them in compression. This makes them very stable and efficient, capable of larger spans, and supporting greater loads than horizontal beams.
The downward load of an arch must be transferred to its foundations. The outward thrust exerted by an arch at its base must be restrained, either by its own weight or the weight of supporting walls, by buttressing or foundations, or by an opposing tie between the two sides. The outward thrust increases as the height, or rise, of the arch decreases.
Building archaeology is the discipline of reconstructing the history of existing buildings using direct observations. Archaeologists can trace a structures past by analysing data such as materials, building techniques, how elements connect with one another, and so on. In a similar way to architectural conservation, building archaeology uses scientific and analytical techniques to describe, assess and date structures.
The main difference between building and excavations archaeology is that the latter requires invasive digging procedures in order to make visible the sources of data, whereas on the whole, a building can be analysed by observation of its exposed surfaces, materials and building techniques without impacting upon the structure itself.
Establishing timelines may not always be the main point of interest for the archaeologist, but it may be necessary to understand dates to obtain an accurate and thorough description of a buildings development, as well placing data within some kind of historical context, which can help identify explanations for the building.
The National Planning Policy Framework (NPPF) Annex 2: Glossary, published by the Ministry of Housing, Communities & Local Government (MHCLG) in 2012, suggests: There will be archaeological interest in a heritage asset if it holds, or potentially holds, evidence of past human activity worthy of expert investigation at some point.
Archigram was a UK-based art and architecture collective that came to prominence in the 1960s. As part of the burgeoning avant garde of the time, it aimed to explore extreme alternatives to urban design as a response to what it perceived to be the dullness and intellectual conservatism of modern architecture.
Archigram was formed in London in 1961 by six young architects:
Warren Chalk - Peter Cook
Peter Cook - Dennis Crompton
Dennis Crompton - David Greene
David Greene - Ron Herron and
Ron Herron and - Michael Webb.
Michael Webb. - Virtually all of their plans and ideas remained unrealised, freeing them to explore unorthodox and outlandish ideas which they often published in their Archigram magazine.
Virtually all of their plans and ideas remained unrealised, freeing them to explore unorthodox and outlandish ideas which they often published in their Archigram magazine.
They were defined less by a specific set of principles, than by an optimistic spirit that corresponded to the prevailing mood of the 1960s, looking to shake off out-dated ideas and conventions. They were inspired by the technocratic ideas of Buckminster Fuller as well as the American Beat movement and Pop art.
In classical architecture, the architrave is the lowest section of the horizontal entablature. It acts as a lintel or beam that rests on the capitals of the vertical columns. It is generally topped with a frieze and cornice. The architrave varies corresponding to the distinguishing features of the main architectural orders Doric, Ionic and Corinthian.
Architraves can also be found in building interiors. Here, an architrave is a moulding that sits above a door, window or other opening, where the architrave extends across the top of the side mouldings to the opening.
However, in the modern construction industry, the term architrave it is frequently used to refer to any horizontal or vertical moulding that forms the surround to a door, window or other opening, the purpose of which is to conceal the joints between the wall or ceiling and the timber casings that form the opening.
Art Deco is a modernist architectural style that flourished in the mid-1920s through to the early-1930s. As well as having a significant influence on architecture, it also extended to fashion, art, sculpture, jewellery and furniture. It is characterised by its distinctive sharp-edges and stylised, geometric, decorative details.
Despite examples being evident in Europe and South America, Art Deco is seen as being synonymous with the American architecture of the time, being the first movement to break from the preceding Revival styles and embodying the ideas of the modern age.
Art Deco first came to public attention in 1922 when Finnish architect Eliel Saarinen entered a design competition for the Chicago Tribune Headquarters. Although it didnt win, the style was widely publicised as being new and exciting.
This view became widespread after the 1925 Exposition Internationale des Art Decoratifs in Paris, a showcase for innovative new design ideas. The style focused on applied decoration and the embellishment of buildings with hard-edged, low-relief designs, as well as geometric shapes such as chevrons and ziggurats, inspired by Native American artwork as well as Egyptian, Babylonian and Assyrian archaeology.
However, it provoked criticism from proponents of modernism such as the Bauhaus movement and Le Corbusier, who viewed Art Deco as vulgar escapism that followed the whims of fashion rather than being rooted in functional realism.
Nonetheless, Art Deco began to grow in popularity and became a commonly adopted style for buildings such as theatres, cinemas, commercial buildings, government buildings, apartments, industrial complexes, and the the emerging building form of the age - the skyscraper.
Art Moderne, also known as Streamline Moderne, is an architectural style that developed out of 1930s Art Deco. It was seen as a response to the Great Depression, designing buildings to be more streamlined and austere as opposed to the ambitious, opulent forms of Art Deco.
Buildings of the Art Moderne style were designed to emphasise simple geometry, incorporating curving forms, long horizontal lines and occasionally nautical elements.
The European Bauhaus movement was influential on American designers who adopted the principle of taking classical architecture in its simplest form, stripped of ornamentation or excess, unlike the chevrons, zigzags and decoration of Art Deco.
Art Moderne buildings were typically designed in low, horizontal shapes as opposed to Art Decos tendency towards tall and vertical buildings. They were also usually white, whereas Art Deco buildings embraced colour. The sharp angles of Art Deco were replaced with simple, aerodynamic curves. Exotic timbers and stone were replaced with stucco, cement and glass.
The Bauhaus was the most influential modernist art school of the 20th century, one whose approach to teaching, and understanding art's relationship to society and technology, had a major impact both in Europe and the United States long after it closed.
It was shaped by the 19th and early-20th century trends such as the Arts and Crafts movement, which had sought to level the distinction between fine and applied arts, and to reunite creativity and manufacturing. This is reflected in the romantic medievalism of the school's early years, in which it pictured itself as a kind of medieval crafts guild.
In the mid-1920s, the medievalism gave way to a stress on uniting art and industrial design, and it was this which ultimately proved to be its most original and important achievement. The school is also renowned for its faculty, which included artists Wassily Kandinsky, Josef Albers, Laszlo Moholy-Nagy, Paul Klee and Johannes Itten, architects Walter Gropius and Ludwig Mies van der Rohe, and designer Marcel Breuer.
Art Nouveau was a movement that emerged towards the end of the 19th century. It had a significant influence on the decorative arts and architecture but was relatively short-lived and fell out of favour in the 1920s with the arrival of Art Deco.
Art Nouveau was symptomatic of the struggle between the old and the new. Whilst it rejected some of the revivalist styles of the 19th century, it did adopt some of the elements of Rococo, with organic forms and applied art typified by Hector Guimard's Paris metro entrances.
Assembly drawings can be used to represent items that consist of more than one component. They show how the components fit together and may include, orthogonal plans, sections and elevations, or three-dimensional views, showing the assembled components, or an exploded view showing the relationship between the components and how they fit together.
They may be used to show how to assemble parts of a kit such as furniture, how to assemble a complex part of a building (an assembly), or to show the relationship between a number of details.
The location of assemblies may be shown on general arrangement drawings, or sometimes on detail drawings. The components that form the assembly may be shown shop drawings that allow their fabrication.
Assembly drawings may include instructions, lists of the component parts, reference numbers, references to detail drawings or shop drawings, and specification information. However, they should not duplicate information provided elsewhere, as this can become contradictory and may cause confusion. They may also include dimensions, notation and symbols. It is important that these are consistent with industry standards so that their precise meaning is clear and can be understood.
An autonomous vehicle (AV) is a self-driving vehicle which requires little or no human direction, can sense its environment, typically navigates by satellite and detects objects in its path that it must avoid.
AVs are not just cars: they can also be trains, ships, trucks, drones, tractors, lunar vehicles and so on. They are typically equipped with computers, software and sensors which gather information about the external environment, and are connected to satellites.
Tensile surfaces, that is, surfaces which carry only tension and no compression or bending, rely on double curvature for their stability. Stability is provided by the opposition of two curvatures which enable the surface to be tensioned without losing its form.
Tensioning the surface reduces its elasticity and so its tendency to deform under load, and the curvature itself means that the surface will deform less for any given extension.
Tensile surfaces can be used in buildings to create thin, long span enclosures, such as roofs for sports stadia, shopping centres, atria and so on. Typically they are constructed using a PVC coated polyester or PTFE coated glass fabric, typically just 1 mm thick.
'Blobitecture', also known as 'blobism', is a term given to a post-modern architectural style characterised by curved and rounded building shapes, or 'blob architecture'. Blobitecture buildings appear to have an organic form that is soft and free-flowing, yet comes together to produce a complex whole.
The design of buildings has historically been limited by the performance of materials found in nature or easily manufactured from available materials. With the modern capability of technology to supply entirely 'artificial' complex substances, with unique performance characteristics the range of possible design forms has grown considerably.
Architecture radicals, such as Archigram in the 1960s, Buckminster Fuller and the deconstructivists, began to design unusual, inflatable and 'plastic' buildings that exploited this potential, and sometimes were even beyond the structural possibilities of the time.
Biotechnology is the application of biological characteristics to make products or solve problems. For example, biotechnology is being applied to environmental processes where enzymes are used to manage toxic materials by either neutralising them or removing them.
Researchers are also applying the theories of biotechnology to the fields of architecture and construction by treating building structures as living organisms.
As a term, biophilia comes from Greek and means a love of nature. Biophilic designs therefore are those that connect people to nature and natural processes, helping people act in more productive ways. The word was first used in this context in The heart of man, a book by German psychologist, Erich Fromann.
Edward Wilson, an American biologist, popularised the term in the 1980s. His concern was that increasing urbanisation was leaving people disconnected from the natural world. In his book Biophilia, he argued that humans have an innate and evolutionarily based affinity for nature and defined the term as referring to, the connections that human beings subconsciously seek with the rest of life.
A more recent explanation was provided by Judith Heerwagen, who undertook extensive research into the relationship between buildings and psychological wellbeing. She suggested that biophilia evolved to guide functional behaviours associated with finding, using and enjoying natural resources that aided survival and reproductive fitness and avoiding those that are harmful.'
Typically, a brick wall is a vertical element of construction that is made of bricks and mortar and is used to form the external walls of buildings, parapets, internal partitions, freestanding walls, retaining walls and so on.
The first walls were made from mud bricks held together by a thin mud slurry, some of which have proved to be surprisingly resilient. A contemporary brick wall is typically made of clay, concrete or calcium-silicate bricks. The most common brick size is 215mm (L) x 102.5mm (W) x 65mm (H). Bricks are bound together by a cementitious or lime mortar, usually 10mm thick for the horizontal (bedding) joints and 10mm wide for the vertical (perpend) joints.
Brick walls can be straight, curved, zig-zag and so on in plan form and typically vary in thickness from 102.5 mm upwards. Brick walls can also be sloped but usually require some form of support to achieve this eg from steelwork or a concrete backing.
Brutalism, also known as Brutalist architecture, is a style that emerged in the 1950s and grew out of the early-20th century modernist movement. Brutalist buildings are characterised by their massive, monolithic and blocky appearance with a rigid geometric style and large-scale use of poured concrete. The movement began to decline in the 1970s, having been much criticised for being unwelcoming and inhuman.
The term Brutalism was coined by the British architects Alison and Peter Smithson, and popularised by the architectural historian Reyner Banham in 1954. It derives from Bton brut (raw concrete) and was first associated in architecture with Le Corbusier, who designed the Cite Radieuse in Marseilles in the late-1940s.
Brutalism became a popular style throughout the 1960s as the austerity of the 1950s gave way to dynamism and self-confidence. It was commonly used for government projects, universities, car parks, leisure and shopping centres, and high-rise blocks of flats.
Brutalism became synonymous with the socially progressive housing solutions that architects and town planners promoted as modern streets in the sky. With an ethos of social utopianism, together with the influence of constructivist architecture, it became increasingly widespread across European communist countries such as the Soviet Union, Bulgaria, Yugoslavia, and Czechoslovakia.
Brutalism was generally characterised by its rough, unfinished surfaces, unusual shapes, heavy-looking materials, straight lines, and small windows. Modular elements were often used to form masses representing specific functional zones, grouped into a unified whole. As well as concrete, other materials commonly used in Brutalist buildings included brick, glass, steel, and rough-hewn stone.
Building acoustics is the science of controlling noise in buildings. This includes the minimisation of noise transmission from one space to another and the control of the characteristics of sound within spaces themselves.
Building acoustics are an important consideration in the design, operation and construction of most buildings, and can have a significant impact on health and wellbeing, communication and productivity. They can be particularly significant in spaces such as concert halls, recording studios, lecture theatres, and so on, where the quality of sound and its intelligibility are very important.
The term 'building fabric' refers to structural materials, cladding, insulation, finishes, etc., that enclose the interior of a building, separating the internal from the external.
Very broadly, for most buildings, the building fabric will include a number of elements:
The roof. - External walls.
External walls. - Windows.
Windows. - Doors.
Doors. - The lowest floor.
The lowest floor. - Each of these will in turn be assemblies of a number of components.
Each of these will in turn be assemblies of a number of components.
Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics to support them.
There are a very wide range of foundation types suitable for different applications, depending on considerations such as:
The nature of the load requiring support. - Ground conditions.
Ground conditions. - The presence of water.
The presence of water. - Space availability.
Space availability. - Accessibility.
Accessibility. - Sensitivity to noise and vibration.
Sensitivity to noise and vibration. - Very broadly, foundations can be categorised as shallow foundations or deep foundations.
Very broadly, foundations can be categorised as shallow foundations or deep foundations.
Shallow foundations are typically used where the loads imposed by a structure are low relative to the bearing capacity of the surface soils.
Deep foundations are necessary where the bearing capacity of the surface soils is not adequate to support the loads imposed by a structure and so those loads need to be transferred to deeper layers with higher bearing capacity.
Computational fluid dynamics (CFD) can play an integral role in all areas of building design, providing accurate and time-efficient simulations of building performance relating to air flow, temperature, pressure and other similar parameters.
In this article, we explore the benefits of computational fluid dynamics software as a design assistance tool and identify where it is actively bridging the gap between architecture and engineering, particularly for architects, heating ventilating and air conditioning (HVAC) engineers - and those in the construction sector who wish to better optimise building designs.
Understanding how natural phenomena affect buildings, particularly internal and external airflows, is an increasingly important aspect of architectural design. This is largely due to the increasing complexity of contemporary buildings and a growing interest in improving building performance in terms of the environmental impact (Kaijima et al., 2013).
CFD has proven to be a key factor for performance enhancement in a number of areas from Formula 1 to the development of swimwear, and the benefits experienced by many industries are now being felt by those in the construction sector.
It is ideal for modelling: -
The thermal comfort of occupants; - Distribution of environmental conditions within a space;
Distribution of environmental conditions within a space; - Effectiveness of natural ventilation (including the stack effect);
Effectiveness of natural ventilation (including the stack effect);
Heat losses through exterior walls or glass; - Effectiveness of air inlets, extractors, radiators:
Effectiveness of air inlets, extractors, radiators:
Build-up of heat in key spaces; - Positioning of sensors to detect heat or cooling;
Positioning of sensors to detect heat or cooling;
Positioning of major HVAC equipment; - Wind loading and forces imposed on a building, and
Wind loading and forces imposed on a building, and
The impact of a new building on air movement around a site.
Traditionally, CFD had many barriers including hefty licenses, large hardware and power requirements, and an intrinsic understanding of the equations involved. Today, vendors have worked to create high performance solutions that can be accessed on-demand, with a pay-as-you-use model, intuitive code and simple graphical user interfaces (GUI).
C-K theory (concept knowledge theory) is a design approach that examines the concept of design as a continuous process that builds on theory and reason. It was developed within the Engineering Design curriculum at Mines ParisTech, Centre for Management Science in the 1990s as an impetus to push designers and engineers to innovate by seeking breakthroughs rather than by improving what is already known.
C-K theory is associated with research, development and academia in the UK, US, France and other parts of the world. It can also be applied to management techniques as a method for inspiring collaborative innovation.
A clerestory is a type of window that is usually found at or near the roof line. It often takes the form of a band of windows across the tops of buildings that allow natural light in without compromising privacy or security.
In Roman architecture, clerestories were often used to light large halls where the interior walls were far apart from the structures exterior walls. Semi-circular windows were often built above the side roofs using groined vaults.
While clerestories were common features during the Roman and Gothic periods of architecture, they are still found today in large buildings such as halls, train stations, gymnasiums, and so on. In domestic buildings, they may take the form of a narrow band of windows along the top of a wall.
Construction Operations Building Information Exchange (COBie) is a non-proprietary data format for the publication of a subset of building information models (BIM) focused on delivering asset data rather than geometric information. It is formally defined as a subset of the Industry Foundation Classes (IFC - the international standard for sharing and exchanging BIM data across different software applications), but can also be conveyed using worksheets or relational databases.
COBie was devised by William East of the United States Army Corps of Engineers, who authored a pilot standard in 2007 to improve the process of handing over information to building owners, occupiers and operators enabling them to manage their asset more efficiently. In 2008 it became COBie when it was revised to comply with international standards for data and classification.
COBie helps capture and record important project data at the point of origin, including equipment lists, product data sheets, warranties, spare parts lists, preventive maintenance schedules and so on. This information is essential to support operations, maintenance and asset management once the built asset is in service.
COBie does not increase the need for information, it simply structures it in a more accessible format, so that it is easier to use and re-purpose. The format is intended to be easy to manage by any organisation, irrespective of size and IT capability. Its simplicity means that all tiers of the supply chain should be able to contribute to the data set, even if just by entering it directly into the spreadsheet. The format also 'insulates' the client from unnecessary complexity, technology changes, interoperability problems and proprietary software issues.
In May 2011 the UK government published the Government Construction Strategy, announcing the government's intention to require Level 2 BIM (collaborative 3D BIM with all project and asset information, documentation and data being electronic) on its projects by 2016. The required submissions of BIM information for Level 2 are in the COBie format. These submissions, or 'data drops' are required at key milestones through the development of projects to ensure they are properly validated and controlled, enabling the client to check the available data in terms of technical compliance, compliance with the brief, cost / price, and so on.
Generally, data drops are aligned to project stages, and the information required reflects the level of development that the project should have reached by that stage. As it develops, the COBie file may contain data from consultants, the contractor, sub-contractors and suppliers, and even the client. Ultimately the data will provide information for the efficient operation and management of the facility.
COBie consists of multiple sheets documenting attributes of the facility, its systems and assets and details of their product types, warranties, maintenance requirements and so on. As the project develops so additional attributes, issues and documentation can be associated to specific items.
In classical architecture, a colonnade is a row of columns spaced at regular intervals in a similar way to a balustrade. They can be used to support a horizontal entablature, an arcade or covered walkway, or as part of a porch or portico. The most iconic example of a portico lined with a colonnade is the Parthenon in Greece. Colonnades can also be used to line open courtyards, and may often be a feature of landscape design.
The use of colonnades dates back to Ancient Greece and Roman architecture where they were used for large public buildings to border open spaces, such as temples and marketplaces.
Colonnades were later used in Baroque and Neoclassical architecture for buildings such as museums and courthouses to create an aesthetic of importance and grandness, such as the Lincoln Memorial in Washington D.C (see image above).
Colonnade size and design can vary. They are usually made from materials such as marble, limestone and painted timber. Larger columns are used for more monumental buildings, while smaller and more slender columns can be found in the Regency architecture of formal homes.
Computer-generated imagery (CGI) is a very broad term that refers to processes involving the use of computer software to create images.
CGI technology has a wide range of uses in the construction industry. Increasingly, architects and other designers, such as interior designers, use CGI to help explore design ideas and to facilitate discussions with clients, contractors and other stakeholders.
Proponents of CGI claim that its many applications can help to inform and refine the design, consultation and construction process, as well as driving efficiency, improving safety and helping to maximise profits.
The emergence of CGI as a project tool has been facilitated by the development of computer aided design (CAD) software and building information modelling (BIM) software that mean much of the information needed to generate CGI on a project has already been created for other purposes.
Until relatively recently, CGI was used predominately to create photo-realistic images of buildings before they had been completed on site. Subsequently real photographs would be taken of the completed building. However, its level of sophistication means that it can now be difficult to distinguish between CGI and photography. Indeed, in an interview with Designing Buildings Wiki, the architectural photographer Paul Grundy explained the challenges faced by traditional photographers of buildings who are increasingly commissioned by architects to replicate CGI renderings photographically.
The term computer aided design (CAD) refers to the use of computers to create graphical representations of physical objects to assist in the design process. It can also refer to the use of computers to prepare presentational images or to prepare production information enabling objects to be manufactured, although sometimes this is referred to as computer aided drafting as it does not necessarily involve designing. In combination, these processes may be referred to as computer-aided design and drafting (CADD).
CAD can be used to create 2D or 3D representations, and can also be used to generate animations and other presentational material. It may allow the addition of supplementary information such as dimensions, descriptions of components, references to specifications and so on.
Specialist CAD software is available for specific purposes, and a wide range of software applications have been developed for use in the design and construction of built assists such as buildings.
Architectural photographers take photographs of buildings and other built structures in a professional capacity. Their photographs are often intended for commercial purposes, for the developer to publish online or in brochures, or for the portfolios of the project team. As potential buyers and clients are often drawn to properties by an image, it is very important that attractive photographs are made available, and the right photographs can be very valuable to those who commission them.
Architectural photographers may be trained photographers who have specialised in architecture through their career, or they may be have a background training as an architect or related profession.
As photographer Paul Grundy said in an interview with Designing Buildings Wiki, it is not essential for an aspiring architectural photographer to study architecture. Universities and colleges offer a variety of different photography courses, during which it may become possible to take a specialist module in architecture. Professional experience can be gained through working as an assistant to a photographer. According to Paul Grundy, "...it takes 10 years of hard work, regardless of what you shoot, to become a professional photographer."
Rendering is the process of applying cement mixture to external, or sometimes internal, walls to achieve a smooth or textured surface. It is similar in technique to plastering.
Render has waterproofing and fire rating qualities, but is also used for aesthetic purposes. It is very common in countries across Europe, particularly around the Mediterranean.
The main components of renders are cement, sand, lime and water. A common mix ratio used for rendering is 6 parts sand, 1 part cement and 1 part lime. Any general purpose cement can be used, although the sand should be fine and clean of impurities. Coarser sand is usually used as the base layer and slightly finer sand for the top layer.
Additives can be included in the mix that help with bonding or slowing the drying process, as well as pigments that alter the colour depending on the aesthetic requirements. By adding lime the render can be given a smoother texture, increasing its elasticity and making it less likely to crack after drying.
Render is usually mixed with a cement mixer which ensures an even mix with the addition of the correct amount of water. Render is then applied using a trowel in thin, smooth coats. A thin finishing top coat or finishing wash can be applied to achieve decorative effects. Depending on the surface texture finish required, top coats may be applied using a trowel, brush or sponge. There is considerable skill involved in achieving different textures, finishing styles and decorative effects.
Offsets can be applied to beam elements.
An offset will allow you to draw the beam at a different physical location than where the neutral axis actually is. The image below shows how the processor sees the beam elements with the beam offsets.
Gross Volume: Gross volume of the Beam element. Calculated by the internal geometry analysis engine, ignoring any subtractions and holes.
Product naming is the discipline of deciding what a product will be called, and is very similar in concept and approach to the process of deciding on a name for a company or organization. Product naming is considered a critical part of the branding process, which includes all of the marketing activities that affect the brand image, such as positioning and the design of logo, packaging and the product itself. The process involved in product naming can take months or years to complete. Some key steps include specifying the objectives of the branding, developing the product name itself, evaluating names through target market testing and focus groups, choosing a final product name, and finally identifying it as a trademark for protection.[1]
Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials.
A Handrail System is an important part of making your ramp or stairs friendly for those who need assistance. Fortress® offers two Handrail Systems, square and round. Both systems integrate with our Fortress railing product lines or can be used with any other railing system to create a safe, durable and beautiful stair installation. Have peace of mind knowing the system is safe, long-lasting and virtually maintenance-free.
What is Site Finished Hardwood? When you opt for site-finished hardwood, you are purchasing wood flooring that will be shipped to your home unfinished to be sanded, possibly stained, and then sealed and finished with a protective layer on the job site in your home.
Air Permeability refers to the amount of air that will travel through a window or door system in its closed position. Air permeability testing relies on the quality of the systems sealing, engineering and manufacturing to ensure that all opening segments seal together well and fully to stop as much air travel through a system as possible.
It is important in terms of comfort to the internal spaces to ensure minimal wind/breeze intrusion and is also an important factor when it comes to environmental factors, to limit the travel of energy from the internal to the external of the system.
The resistance wind load is the capacity of a window, subjected to strong pressures, like that caused by wind, to maintain an acceptable deformation and to preserve its property.
The bending strength or flexural strength of a material is defined as its ability to resist deformation under load. During a bending test described in ASTM D790 the maximum achieved flexural stress value is noted as flexural strength. For materials that deform significantly but do not break, the load at yield, typically measured at 5% deformation/strain of the outer surface, is reported as the flexural strength or flexural yield strength. The test beam is under compressive stress at the concave surface and tensile stress at the convex surface. In the figure (source: ASTM.org) three examples are shown.
Global warming potential (GWP) is the heat absorbed by any greenhouse gas in the atmosphere, as a multiple of the heat that would be absorbed by the same mass of carbon dioxide (CO 2).
In mechanics, compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size (as opposed to tensile strength which withstands loads tending to elongate). In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently.